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Potential use of iPS cells to combat acute kidney disease …

Whilst transplantation often remains the only effective treatment for acute kidney disease, a new study from Kyoto University points to a future where renal progenitor cells derived from iPSCs could be transplanted into affected kidneys to combat these debilitating conditions.

In recent years, a popular avenue of investigation for treating kidney disease and damage has been transplantation of renal progenitor cells (RPCs), which can develop into the variety of cells required for organ repair. One problem with this line of study has been growing the number of RPCs required for effective treatment. This investigation, lead by Professor Kenji Osafune and published in Stem Cells Translational Medicine, shows iPSCs can be expanded and differentiated into RPCs at high enough levels to make them a strong candidate for the therapy.

One issue outstanding with this potential therapy is the difficulty associated with transplanting the RPCs directly into kidney parenchyma, with few studies managing to introduce sufficient cell numbers. The kidney is a very solid organ, which makes it very difficult to bring enough number of cells upon transplantation, Osafune explained.

To circumvent this problem, the team transplanted RPCs derived from iPSCs into the kidney subcapsule at the kidney surface. These cells never integrated into the host organ, but the mice receiving the treatment showed better recovery from their acute kidney injury nevertheless. Compared to control experiments, introduction of RPCs was concomitant with reduced necrosis and fibrosis of the damaged kidneys. Osafune has suggested that these improvements may be due to the RPCs expressing two known renal progenitor marker proteins, Osr1 and Six2, which have not been tested together until now.

As the cells did not integrate into the host kidney, another mode of action must have caused the benefits observed. The study concluded that paracrine secretions of renal protective factors from the RPCs caused the improvements seen in the treated mice. As kidney fibrosis marks progression towards chronic disease, Osafune hinted the paracrine secretions could be utilised as a preventative therapy for other diseases, or give clues for drug discovery. There is no medication for acute kidney injury. If we can identify the paracrine factor, maybe it will lead to a drug.

Sources: Toyohara T, Mae SU, Sueta SU et al. Cell Therapy Using Human Induced Pluripotent Stem Cell-Derived Renal Progenitors Ameliorates Acute Kidney Injury In Mice. Stem Cells Translational Medicine. doi: 10.5966/sctm.2014-0219

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New gene therapy research to treat genetic deafness …

Posted on: Friday, July 31, 2015 by Nicola Robas

We are a step closer to being able to prevent some types of inherited deafness thanks to ground breaking research showing that gene therapy has been successfully used in mice to restore hearing. Nicola Robas from our Biomedical Research team tells us more.

The instructions for how our bodies develop and function are contained in our genes. We each have small variations in our genetic instructions but most of the time these differences do not alter how a gene functions. However, sometimes the differences can stop a gene from working properly. If this occurs in a gene needed for hearing it can lead to deafness (known as genetic or inherited deafness). So far scientists have identified over 100 genes that can cause genetic hearing loss. While our ability to diagnose genetic hearing loss has vastly improved, the current treatments remain limited to hearing aids and cochlear implants. These devices can be very effective at improving hearing but they cannot help everyone with inherited deafness, and they do not fix the root cause of the hearing loss.

Researchers have been looking at one particular type of inherited hearing loss caused by changes in a gene called TMC1. The protein produced by the TMC1 gene forms part of the machinery in the sound-sensing hair cells of the inner ear that converts mechanical sound waves into electrical signals that are then sent to the brain, allowing us to perceive sound. If TMC1 is not working correctly, then sound signals cannot be sent from the ear to the brain, leading to a hearing loss. In people, changes in TMC1 can cause 2 forms of deafness. In the most common form of TMC1-related deafness, children become profoundly deaf from a very young age, usually around two years old. The second causes children to go deaf gradually from about the age of 10 to 15.

Gene therapy to replace a faulty gene with a normally functioning copy has the potential to prevent certain types of genetic deafness. New research, led by scientists at Harvard Medical School, has shown in mice, that gene therapy can restore the hearing of animals with a faulty TMC1 gene. A virus engineered to produce a healthy copy of this gene was injected into the cochlea of mice in which TMC1 wasnt working correctly (thereby acting as an experimental model of the human form of deafness).

25 days after the injection the mice showed a partial recovery of hearing. The mice went from having a profound hearing loss to a point where, if they were people, they would benefit from a hearing aid. The researchers think that only a partial recovery was seen because the virus delivering the gene was not able to reach all the cells it needed to. There are two types of sound-sensing hair cells in the ear – inner hair cells that activate the auditory nerves carrying sound signals to the brain, and outer hair cells that amplify sound vibrations allowing people to hear really quiet sounds. TMC1 is needed by both cell types, but the virus was only able to get into and rescue the inner hair cells.

At least half of all childhood deafness is inherited and we know there are more than 100 different genes that can cause deafness. If shown to work in people, then this gene therapy has the potential to cure one specific type of genetic deafness (TMC1-related deafness). TMC1 accounts for around 6% of genetic deafness so, if this approach is successful, it will only have a direct benefit for a small number of families. However, more people could benefit in the future as the same technology could be adapted to treat other types of inherited deafness just delivering a healthy copy of a different gene. The only problem is that many forms of inherited deafness affect the ear before birth so in these cases, a childs ear would need to be treated during pregnancy which, with the technology and surgical techniques available today, would be very difficult. So for now, gene therapy to replace faulty genes is likely to be limited to treating progressive forms of inherited deafness that start after birth.

At the moment, this gene therapy is not yet ready to be tested in people. More work still needs to be done in the laboratory to refine the techniques, improve the way the virus delivers the healthy gene, understand how long the effect lasts for, and gather enough data to deem the approach safe and effective. If all goes well, the researchers hope to begin clinical trials in people in 5 years.

This research was published in the journal Science Translational Medicine

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biomedical research – Genentech

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Chris Bowden explains the RAS-RAF pathway, an important and evolving area of cancer research.

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doctor Gene Therapy TV the Human Genetic Revolution

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I had spent two years in physical therapy while being bounced from Specialist to Specialist, all who repeatedly told me they did not know what was wrong or how to fix my lower back pain. The problem was that my right SI joint would slip out of place, causing severe pain and considerable restriction. It seemed the only solution would be to fuse the joint, but every Doctor refused because I was only 25 years old.

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Biologic Healing Regenerative Medicine

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Having someone elses marrow or stem cells is called a donor transplant, or an allogeneic transplant. This is pronounced al-lo-jen-ay-ik.

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Bone marrow or stem cell transplants for AML | Cancer …

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Female Behaviour Drives Expression and Evolution of …

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PLOS Genetics

By Adriana D. Briscoe, Aide Macias-Muoz, Krzysztof M. Kozak, James R. Walters, Furong Yuan, Gabriel A. Jamie, Simon H. Martin, Kanchon K. Dasmahapatra, Laura C. Ferguson, James Mallet, Emmanuelle Jacquin-Joly, Chris D. Jiggins | Published 7/30/2015

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Genetic female | definition of genetic female by Medical …

genetic female

1. a person with a normal female karyotype, including two X chromosomes;

2. a person whose cell nuclei contain Barr sex chromatin bodies, which are normally absent in males.

1. An individual with a normal female karyotype, including two X-chromosomes.

2. An individual whose cell nuclei contain Barr bodies.

1. A person with a normal female karyotype, including two X chromosomes.

2. A person whose cell nuclei contain Barr sex chromatin bodies, which are normally absent in males.

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Genetics – biology

Genetics

Background:

Homunculus in Sperm One question that has always intrigued us humans is Where did we come from? Long ago, Hippocrates and Aristotle proposed the idea of what they called pangenes, which they thought were tiny pieces of body parts. They thought that pangenes came together to make up the homunculus, a tiny pre-formed human that people thought grew into a baby. In the 1600s, the development of the microscope brought the discovery of eggs and sperm. Antonie van Leeuwenhoek, using a primitive microscope, thought he saw the homunculus curled up in a sperm cell. His followers believed that the homunculus was in the sperm, the father planted his seed, and the mother just incubated and nourished the homunculus so it grew into a baby. On the other hand, Regnier de Graaf and his followers thought that they saw the homunculus in the egg, and the presence of semen just somehow stimulated its growth. In the 1800s, a very novel, radical idea arose: both parents contribute to the new baby, but people (even Darwin, as he proposed his theory) still believed that these contributions were in the form of pangenes.

Modern genetics traces its beginnings to Gregor Mendel, an Austrian monk, who grew peas in a monastery garden. Mendel was unique among biologists of his time because he sought quantifiable data, and actually counted the results of his crosses. He published his findings in 1865, but at that time, people didnt know about mitosis and meiosis, so his conclusions seemed unbelievable, and his work was ignored until it was rediscovered in 1900 by a couple of botanists who were doing research on something else. Peas are an ideal organism for this type of research because they are easy to grow and it is easy to control mating.

We will be looking at the sorts of genetic crosses Mendel did, but first, it is necessary to introduce some terminology:

Monohybrid Cross and Probabilities:

A monohybrid cross is a genetic cross where only one gene/trait is being studied. P stands for the parental generation, while F1 and F2 stand for the first filial generation (the children) and second filial generation (the grandchildren). Each parent can give one chromosome of each pair, therefore one allele for each trait, to the offspring. Thus, when figuring out what kind(s) of gametes an individual can produce, it is necessary to choose one of the two alleles for each gene (which presents no problem if they are the same).

Purple Pea Flower White Pea Flower For example, a true-breeding purple-flowered plant (the dominant allele for this gene) would have the genotype PP, and be able to make gametes with either P or P alleles. A true-breeding white-flowered plant (the recessive allele for this gene) would have the genotype pp, and be able to make gametes with either p or p alleles. Note that both of these parent plants would be homozygous. If one gamete from each of these parents got together to form a new plant, that plant would receive a P allele from one parent and a p allele from the other parent, thus all of the F1 generation will be genotype Pp, they will be heterozygous, and since purple is dominant, they will look purple. What if two individuals from the F1 generation are crossed with each other (PpPp)? Since gametes contain one allele for each gene under consideration, each of these individuals could contribute either a P or a p in his/her gametes. Each of these gametes from each parent could pair with each from the other, thus yielding a number of possible combinations for the offspring. We need a way, then, to predict what the possible offspring might be. Actually, there are two ways of doing this. The first is to do a Punnett square (named after Reginald Crandall Punnett). The possible eggs from the female are listed down the left side, and there is one row for each possible egg. The possible sperm from the male are listed across the top, and there is one column for each possible sperm. The boxes at the intersections of these rows and columns show the possible offspring resulting from that sperm fertilizing that egg. The Punnett square from this cross would look like this:

Note that the chance of having a gamete with a P allele is and the chance of a gamete with a p allele is , so the chance of an egg with P and a sperm with P getting together to form an offspring that is PP is =, just like the probabilities involved tossing coins. Thus, the possible offspring include: PP, ( Pp + pP, which are the same (Pp), since P is dominant over p), so = Pp, and pp.

Another way to calculate this is to use a branching, tree diagram:

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View Bioidentical Hormone Doctors Nationwide

Our Directory of Bioidentical Hormone Doctors is dedicated to helping you find qualified Bioidentical Hormone Doctors that will provide you with the general guidance needed to obtain the best possible results and optimum natural hormone levels.

Our directory of Bioidentical Hormone Doctors specialize in many aspects of anti-aging and natural hormone therapy to treat conditions such as perimenopause, menopause, andropause and thyroid function.

We also Feature Many Bioidentical Hormone Doctors inCanada

CANADA BIOIDENTICAL HORMONE DOCTORS Find Bioidentical Hormone Doctors in Alberta, British Columbia, Ontario, Manitoba, New Brunswick and more.

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Hormone and Wellness Center of Texas – Hormone Replacement …

Hormone and Wellness Centers of Texas offers an expertise in hormone replacement therapy and high ethical standards for all of their products and services.

Hormone and Wellness Centers of Texas has a commitment to the highest standards of personal care while serving men and woman so that they can live a more fulfilled life.

10 Myths about Hormone Replacement Therapy

Amino acids are the building blocks of every structure in your skin. Essential skin proteins like collagen, elastin, lipids and all cellular tissues are made from amino acids. We derive the amino acids in our products from 17 different plant sources because it gives us a pure version of the desired amino acids.

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Stem Cells Show Promise in Heart Failure Treatment

A new method for delivering stem cells to damaged heart muscle has shown early promise in treating severe heart failure, researchers report.

In a preliminary study, they found the tactic was safe and feasible for the 48 heart failure patients they treated. And after a year, the patients showed a modest improvement in the heart’s pumping ability, on average.

It’s not clear yet whether those improvements could be meaningful, said lead researcher Dr. Amit Patel, director of cardiovascular regenerative medicine at the University of Utah.

He said larger clinical trials are underway to see whether the approach could be an option for advanced heart failure.

Other experts stressed the bigger picture: Researchers have long studied stem cells as a potential therapy for heart failure — with limited success so far.

“There’s been a lot of promise, but not much of a clinical benefit yet,” said Dr. Lee Goldberg, who specializes in treating heart failure at the University of Pennsylvania.

Researchers are still sorting through complicated questions, including how to best get stem cells to damaged heart muscle, said Goldberg, who was not involved in the new study.

What’s “novel” in this research, he said, is the technique Patel’s team used to deliver stem cells to the heart. They took stem cells from patients’ bone marrow and infused them into the heart through a large vein called the coronary sinus.

Patel agreed that the technique is the advance.

“Most other techniques have infused stem cells through the arteries,” Patel explained. One obstacle, he said, is that people with heart failure generally have hardened, narrowed coronary arteries, and the infused stem cells “don’t always go to where they should.”

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Stem Cells Show Promise in Heart Failure Treatment

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New blood cancer drug reaches cells hiding in bone marrow …

SAN DIEGO, July 28 (UPI) — A new drug aimed at dormant cancer stem cells that hide in the hypoxic zones of bone marrow, where most drugs can’t reach, is currently entering 5 Phase II clinical trials after it was shown to make blood cancer treatment more effective.

Researchers in a Phase I clinical trial, the results of which are published in The Lancet Haematology, found that the drug vismodegib was effective against three types of blood cancer — refractory or resistant myeloid leukemia, myelodysplastic syndrome and myelofibrosis.

Vismodegib inhibits the Hedgehog signaling pathway, which is essential to both vertebrate embryonic development and has been implicated in the development of some cancers. The drug, trade name Erivedge, is already approved in the U.S. and Europe for treatment of metastatic or locally advanced basal cell carcinoma.

“Our hope is that this drug will enable more effective treatment to begin earlier and that with earlier intervention, we can alter the course of disease and remove the need for, or improve the chances of success with, bone marrow transplantation,” said Dr. Catriona Jamieson, chief of the Division of Regenerative Medicine in the School of Medicine at the University of California San Diego, in a press release. “It’s all about reducing the burden of disease by intervening early.”

Preclinical research showed the drug could “coax” dormant cancer stem cells in hypoxic zones to begin differentiating and enter the bloodstream, where they can be attacked by the chemotherapy and the immune system.

In the study, researchers treated 47 adults with blood and marrow cancers with with the drug in 28-day cycles. Treatment cycles were continued with escalating doses until a participant experienced adverse effects with no improvement in their condition. The participants who did not have adverse reactions or serious side effects continued to receive treatment cycles of the drug.

Serious adverse effects were seen in only 3 of the participants, though 60 percent of the group experienced treatment-related problems. Nearly half the people in the study saw positive clinical activity as a result of treatment with vismedogib, the researchers said, and 5 Phase II clinical trials are being scheduled for the drug for use with blood cancer.

“This drug gets that unwanted house guests to leave and never come back,” Jamieson said. “It’s a significant step forward in treating people with refractory or resistant myeloid leukemia, myelodysplastic syndrome and myelofibrosis. It’s a bonus that the drug can be administered as easily as an aspirin, in a single, daily oral tablet.”

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Skin Stem Cells: Benefits, Types, Medical Applications and …

Our skin has the amazing capability to renew itself throughout our adult life. Also, our hair follicle goes through a cycle of growth and degeneration. This happens all the time in our skin even though we are not aware of it. However, even though skin renews itself we still have to help it a little bit to get better results. Stem cells play an important role in this process of skin renewal or hair growth and the purpose of this article is to discuss and provide additional information about these tiny cells that play a big part in our life.

Skin stem cell is defined as multipotent adult skin cells which are able to self-renew or differentiate into various cell lineages of the skin. These cells are active throughout our life via skin renewal process or during skin repair after injuries. These cells reside in the epidermis and hair follicle and one of their purposes is to ensure the maintenance of adult skin and hair regeneration.

The truth is, without these little cells, our skin wouldnt be able to cope with various environmental influences. Our skin is exposed to different influences 24/7, for example, washing your face with soap, going out during summer or cold winter days etc. All these factors have a big impact on our skin and it constantly has to renew itself to stay in a good condition. This is where skin stem cells step in. They make sure your skin survives the influence of constant stress, heat, cold, even makeup, soap, etc.

Our skin is quite sensitive and due to its constant exposure to different influences throughout the day, it can get easily damage. Damage to skin cells can be caused by pretty much everything, from soap to cigarette smoke. One of the most frequent skin cell damages are the result of:

Skin stem cells are still subjected to scientific projects where researchers are trying to discover as much as possible about them. So far, they have identified several types of these cells, and they are:

Also, some scientists suggest that there is another type of stem cells mesenchymal stem cells which can be found in dermis (layer situated below the epidermis) and hypodermis (innermost and the thickest layer of the skin). However, this claim has been branded controversial and is a subject of many arguments and disputes between scientists. It is needed to conduct more experiments to find out whether this statement really is true.

Stem cells are found in many organs and tissues, besides skin. For example, scientists have discovered stem sells in brain, heart, bone marrow, peripheral blood, skeletal muscle, teeth, liver, gut etc. Stem cells reside in a specific area of each tissue or organ and that area is called stem cell niche. The same case is with the skin as well.

The ability of stem cells to regenerate and form almost any cell type in the body inspired scientists to work on various skin products that contain stem cells. Also, they decided to investigate the effect of plant stem cells on human skin. They discovered that plant stem cells are, actually, very similar to human skin stem cells and they function in a similar way as well. This discovery made scientists turn to plants as the source of stem cells and are trying to include them into the skin products due to their effectiveness in supporting skins cellular turnover. Another similarity between plant stem cells and human skin stem cells is their ability to develop according to their environment.

Fun Fact: The inspiration to use plant stem cells in skin care came from an unusual place almost extinct apple tree from Switzerland.

The benefits of plant stem cells on human skin are versatile. They offer possibility to treat some skin conditions, heal wounds, and repair the skin after some injury faster than it would usually take. Also, they bring back elasticity to the skin, reduce the appearance of wrinkles and slow down the aging process.

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International Society for Cellular Therapy

ISCT is a global society of clinicians, regulators, technologists, and industry partners with a shared vision to translate cellular therapy into safe and effective therapies to improve patients lives. ISCT Members gain access to an influential global community of peers, experts, and organizations invested in cell therapy. ISCT offers a unique collaboration between academia, regulatory bodies, and industry partners in cell therapy translation. Join us today!

To drive the translation of all cellular therapies for the benefit of patients worldwide.

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International Society for Cellular Therapy

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Research Specialist, Gene Therapy Job

Jobing Description

Who we are:

Calico is a research and development company whose mission is to harness advanced technologies to increase our understanding of the biology that controls lifespan. We will use that knowledge to devise interventions that enable people to lead longer and healthier lives. Executing on this mission will require an unprecedented level of interdisciplinary effort and a long-term focus for which funding is already in place.

Position description:

Calico is recruiting biologists to work as part of a cutting-edge research team focused on studying and experimentally altering age-related physiological dysfunction in preclinical models. We are particularly excited about candidates with experience in gene therapy, vector-based delivery of genetic material in vivo, cell-based therapeutic strategies, and physiological endpoints in preclinical models. Experience with genome-editing technologies and pluripotent cell culture is a plus. The successful candidate will develop gene therapy tools to regulate biological networks in a temporal and tissue-specific manner, and to use those tools to alter age-related physiological dysfunction in a manner relevant to future clinical therapy.

Position requirements:

A Ph.D. in biology, cell biology, molecular biology, genetics, or biochemistry with a completed postdoc or 3+ years of additional, relevant experience, with a strong track record of research productivity as evidenced by high-quality, impactful publications. You need to be an enthusiastic team player, thrive on attention to detail, have excellent verbal/written communication skills, and be excited about studying aging!

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Research Specialist, Gene Therapy Job

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Gene Therapy Research

The articles in gene therapy institutes category describe the institutional organisations conducting gene therapy research. We are particurarly interested in hearing from professors who have set up a gene therapy institute or from consortia of researchers who are funded from grants focussing on gene therapy.

If you want more details of your gene therapy institute or group to feature on the Gene Therapy Review, then please contact usfor a brochure detailing the options open to academic researchers.

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WHO | Genetic research

The role of genetic research is indispensable in the ever challenging fields of diagnosis and treatment of genetic disorders, infectious diseases and non communicable diseases. Main areas of genetic research include:

Researchers and policy makers alike are continuously assessing the value of this research in terms of its utility and cost-effectiveness for public health.

To provide information on genetic research, this section includes online articles from journals that address recent discoveries, advanced technologies, and current treatment options in the area of genetic.

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Male-pattern hair loss – Wikipedia, the free encyclopedia

Male-pattern hair loss, also known as androgenic alopecia and male pattern baldness (MPB), is hair loss that occurs due to an underlying susceptibility of hair follicles to androgenic miniaturization. It is the most common cause of hair loss and will affect up to 70% of men and 40% of women at some point in their lifetimes. Men typically present with hairline recession at the temples and vertex balding, while women normally thin diffusely over the top of their scalps.[1][2][3] Both genetic and environmental factors play a role, and many etiologies remain unknown.

Classic androgenic hair loss in males begins above the temples and vertex, or calvaria, of the scalp. As it progresses, a rim of hair at the sides and rear of the head remains. This has been referred to as a ‘Hippocratic wreath’, and rarely progresses to complete baldness.[4] The Hamilton-Norwood scale has been developed to grade androgenic alopecia in males.

Female androgenic alopecia is known colloquially as “female pattern baldness”, although its characteristics can also occur in males. It more often causes diffuse thinning without hairline recession; and, like its male counterpart, rarely leads to total hair loss.[5] The Ludwig scale grades severity of androgenic alopecia in females.

Animal models of androgenic alopecia occur naturally and have been developed in transgenic mice;[6]chimpanzees (Pan troglodytes); bald uakaris (Cacajao rubicundus); and stump-tailed macaques (Macaca speciosa and M. arctoides). Of these, macaques have demonstrated the greatest incidence and most prominent degrees of hair loss.[7][8]

Androgenic alopecia is typically experienced as a “moderately stressful condition that diminishes body image satisfaction”.[9] However, although most men regard baldness as an unwanted and distressing experience, they usually are able to cope and retain integrity of personality.[10]

Research indicates that the initial programming of pilosebaceous units begins in utero.[11] The physiology is primarily androgenic, with dihydrotestosterone (DHT) the major contributor at the dermal papillae. Below-normal values of sex hormone-binding globulin, follicle-stimulating hormone, testosterone, and epitestosterone are present in men with premature androgenic alopecia compared to normal controls.[12] Although follicles were previously thought permanently gone in areas of complete hair loss, they are more likely dormant, as recent studies have shown the scalp contains the stem cell progenitors from which the follicles arose.[13]

Transgenic studies have shown that growth and dormancy of hair follicles are related to the activity of insulin-like growth factor at the dermal papillae, which is affected by DHT.[14]Androgens are important in male sexual development around birth and at puberty. They regulate sebaceous glands, apocrine hair growth, and libido. With increasing age,[15] androgens stimulate hair growth on the face, but suppress it at the temples and scalp vertex, a condition that has been referred to as the ‘androgen paradox’.[16]

These observations have led to study at the level of the mesenchymal dermal papillae.[17][18]Types 1 and 2 5 reductase enzymes are present at pilosebaceous units in papillae of individual hair follicles.[19] They catalyze formation of the androgens testosterone and DHT, which in turn regulate hair growth.[16] Androgens have different effects at different follicles: they stimulate IGF-1 at facial hair, leading to growth, but stimulate TGF 1, TGF 2, dickkopf1, and IL-6 at the scalp, leading to catagenic miniaturization.[16] Hair follicles in anaphase express four different caspases. Tumor necrosis factor inhibits elongation of hair follicles in vitro with abnormal morphology and cell death in the bulb matrix.[20]

Studies of serum levels of IGF-1 show it to be increased with vertex balding.[21][22] Earlier work looking at in vitro administration of IGF had no effect on hair follicles when insulin was present, but when absent, caused follicle growth. The effects on hair of IGF-I were found to be greater than IGF-II.[23] Later work also showed IGF-1 signalling controls the hair growth cycle and differentiation of hair shafts,[14] possibly having an anti-apoptotic effect during the catagen phase.[24]In situ hybridization in adult human skin has shown morphogenic and mitogenic actions of IGF-1.[25] Mutations of the gene encoding IGF-1 result in shortened and morphologically bizarre hair growth and alopecia.[26] IGF-1 is modulated by IGF binding protein, which is produced in the dermal papilla.[27]

DHT inhibits IGF-1 at the dermal papillae.[28] Extracellular histones inhibit hair shaft elongation and promote regression of hair follicles by decreasing IGF and alkaline phosphatase in transgenic mice.[29] Silencing P-cadherin, a hair follicle protein at adherens junctions, decreases IGF-1, and increases TGF beta 2, although neutralizing TGF decreased catagenesis caused by loss of cadherin, suggesting additional molecular targets for therapy. P-cadherin mutants have short, sparse hair.[30]

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Male Hormone Replacement – Testosterone – The Turek Clinic

The average age of men in the US is projected to rise significantly over the next 25 years, with the greatest increase occurring in men > 65 years old.

As this happens, there will be a dramatic increase in age-related health problems too, including cancer, strokes, heart disease and hormone deficiency. Although the health risks associated with age-related hormonal decline in women, termed menopause, have been thoroughly addressed, it has now been shown that hormonal changes in the aging male are associated with significant health problems.

Specialty board certified Dr. Paul Turek at The Turek Clinic, a Best Doctors in America choice for 7 years running, has expertise and interest in helping patients understand all of the issues, good and bad, that surround testosterone replacement therapy in men of all ages.

To learn more about male hormone replacement, please select one of the following topics. If you are ready to schedule a consultation with Dr. Turek, please request a consultation here.

There is a progressive decline in testosterone production in men with age. These changes can be dramatic, such that 50% of men >60 years old have low levels of testosterone. Although the rate of decline varies widely, a general rule of thumb is that testosterone levels decrease about 1% yearly after age 50. Despite the fact that it is not as rapid a drop in hormones as women get with menopause, it certainly is just as real. This has been termed male menopause, male climacteric, andropause, or more appropriately, partial androgen deficiency in the aging male (PADAM). Serum testosterone levels in men fall progressively from the third decade to the end of life, mainly due to a decline in the cells in the testis that make the hormone (Leydig cells). This decline may also be due to changes in hormones (GnRH, LH) and proteins (SHBG, albumin) that regulate testosterone production.

One issue with testosterone that complicates matters is the fact that it exists in several different forms in the blood, and each form has different hormonal activity (Figure 1). Free or unbound testosterone is a fully active hormone, but protein-bound testosterone are only partly active, or sometimes completely inactive. What is usually measured in a blood draw is the total testosterone, which is a combination of the free and protein-bound forms. An analogy to explain this is to think of the total testosterone as all of the cars in a parking lot.

Importantly, though, only the cars that can start or drive are useful or active. Free testosterone comprises all of the cars that can start and be driven away, but the protein-bound testosterone are those cars that may or may not start, and those that may or may not be able to be driven away. So, aging is associated with 1) lower total testosterone production (fewer cars in the lot) and 2) higher levels of certain proteins that bind testosterone (sex hormone-binding globulin, SHBG), such that even fewer cars can start and run, and it is this combination of events that leads to declining testosterone activity with age. Thus, the complex physiology of testosterone balance often clouds the interpretation of age-related declining levels of the hormone.

Testosterone affects the function of many organs in the body (Table 1). In the brain, it influences libido or sex drive, male aggression, mood and thinking. Testosterone can improve verbal memory and visual-spatial skills. It as also been shown to decrease fatigue and depression in men with low levels. It is responsible for muscle strength and growth, and stimulates stem cells and blood cells in bones and kidneys. Penile growth, erections, sperm production, and prostatic growth and function all depend on testosterone. It also causes body hair growth, balding, and drives beard growth. Thus, testosterone makes us who we are, and influences how we look.

In men with low testosterone levels, testosterone can improve bone mineral density and reduce bone fractures, an effect similar to that found in postmenopausal women on estrogen replacement. Importantly, hip fractures are 2-3 times as likely to kill an older man as a woman of the same age, and 40% of older male patients with hip fractures die within 1 year of the injury.

Testosterone results in increases in lean body mass, possibly strength and can decrease fat mass. By stimulating erythropoietin, testosterone increases blood counts. It appears to improve lipid profiles and dilates blood vessels in the heart but no data has yet shown that it reduces heart attacks or strokes. It appears not to alter LDL or total cholesterol levels. In recent work, it has been shown that men with chronically low testosterone levels have 2-3 fold higher risk of developing metabolic syndrome and have up to a 40% greater risk of death than men with normal testosterone levels.

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Hypergonadotropic hypogonadism – Wikipedia, the free …

Hypergonadotropic hypogonadism (HH), also known as primary or peripheral/gonadal hypogonadism, is a condition which is characterized by hypogonadism due to an impaired response of the gonads to the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), and in turn a lack of sex steroid production and elevated gonadotropin levels (as an attempt of compensation by the body). HH may present as either congenital or acquired, but the majority of cases are of the former nature.[1][2]

There are a multitude of different etiologies of HH. Congenital causes include the following:[1][3][4]

Acquired causes (due to damage to or dysfunction of the gonads) include gonadal torsion, vanishing/anorchia, orchitis, premature ovarian failure, ovarian resistance syndrome, trauma, surgery, autoimmunity, chemotherapy, radiation, infections (e.g., sexually-transmitted diseases), toxins (e.g., endocrine disruptors), and drugs (e.g., antiandrogens, opioids, alcohol).[1][3][4]

Examples of symptoms of hypogonadism include delayed, reduced, or absent puberty, low libido, and infertility.

Treatment of HH is usually with hormone replacement therapy, consisting of androgen and estrogen administration in males and females, respectively.[3]

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XY sex-determination system – Wikipedia, the free encyclopedia

The XY sex-determination system is the sex-determination system found in humans, most other mammals, some insects (Drosophila), and some plants (Ginkgo). In this system, the sex of an individual is determined by a pair of sex chromosomes (gonosomes). Females have two of the same kind of sex chromosome (XX), and are called the homogametic sex. Males have two distinct sex chromosomes (XY), and are called the heterogametic sex.

This system is in contrast with the ZW sex-determination system found in birds, some insects, many reptiles, and other animals, in which the heterogametic sex is female.

A temperature-dependent sex determination system is found in some reptiles.

All animals have a set of DNA coding for genes present on chromosomes. In humans, most mammals, and some other species, two of the chromosomes, called the X chromosome and Y chromosome, code for sex. In these species, one or more genes present on their Y-chromosome that determine maleness. In this process, an X chromosome and a Y chromosome act to determine the sex of offspring, often due to genes located on the Y chromosome that code for maleness. Offspring have two sex chromosomes: an offspring with two X chromosomes will develop female characteristics, and an offspring with an X and a Y chromosome will develop male characteristics.

In humans, a single gene (SRY) present on the Y chromosome acts as a signal to set the developmental pathway towards maleness. Presence of this gene starts off the process of virilization. This and other factors result in the sex differences in humans.[1] The cells in females, with two X chromosomes, undergo X-inactivation, in which one of the two X chromosomes is inactivated. The inactivated X chromosome remains within a cell as a Barr body.

Humans, as well as some other organisms, can have a chromosomal arrangement that is contrary to their phenotypic sex; for example, XX males or XY females (see androgen insensitivity syndrome). Additionally, an abnormal number of sex chromosomes (aneuploidy) may be present, such as Turner’s syndrome, in which a single X chromosome is present, and Klinefelter’s syndrome, in which two X chromosomes and a Y chromosome are present, XYY syndrome and XXYY syndrome.[1] Other less common chromosomal arrangements include: triple X syndrome, 48, XXXX, and 49, XXXXX.

XY system in mammals: Sex is determined by presence of Y. “Female” is the default sex; due to the absence of the Y.[2] In the 1930s, Alfred Jost determined that the presence of testosterone was required for Wolffian duct development in the male rabbit.[3]

SRY is an intronless sex-determining gene on the Y chromosome in the therians (placental mammals and marsupials).[4] Non-human mammals use several genes on the Y-chromosome. Not all male-specific genes are located on the Y-chromosome. Other species (including most Drosophila species) use the presence of two X chromosomes to determine femaleness. One X chromosome gives putative maleness. The presence of Y-chromosome genes is required for normal male development.

Birds and many insects have a similar system of sex determination (ZW sex-determination system), in which it is the females that are heterogametic (ZW), while males are homogametic (ZZ).

Many insects of the order Hymenoptera instead have a system (the haplo-diploid sex-determination system), where the males are haploid individuals (which just one chromosome of each type), while the females are diploid (with chromosomes appearing in pairs). Some other insects have the X0 sex-determination system, where just one chromosome type appears in pairs for the female but alone in the males, while all other chromosomes appear in pairs in both sexes.

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Sexual differentiation – Wikipedia, the free encyclopedia

Sexual differentiation

Differentiation of the male and female reproductive systems does not occur until the fetal period of development.

Sexual differentiation is the process of development of the differences between males and females from an undifferentiated zygote. As male and female individuals develop from zygotes into fetuses, into infants, children, adolescents, and eventually into adults, sex and gender differences at many levels develop: genes, chromosomes, gonads, hormones, anatomy, and psyche.

Sex differences range greatly and include physiologically differentiating. Sex-dichotomous differences are developments which are wholly characteristic of one sex only. Examples of sex-dichotomous differences include aspects of the sex-specific genital organs such as ovaries, a uterus or a phallic urethra. In contrast, sex-dimorphic differences are matters of degree (e.g., size of phallus). Some of these (e.g., stature, behaviors) are mainly statistical, with much overlap between male and female populations.

Nevertheless, even the sex-dichotomous differences are not absolute in the human population, and there are individuals who are exceptions (e.g., males with a uterus, or females with an XY karyotype), or who exhibit biological and/or behavioral characteristics of both sexes.

Sex differences may be induced by specific genes, by hormones, by anatomy, or by social learning. Some of the differences are entirely physical (e.g., presence of a uterus) and some differences are just as obviously purely a matter of social learning and custom (e.g., relative hair length). Many differences, though, such as gender identity, appear to be influenced by both biological and social factors (“nature” and “nurture”).

The early stages of human differentiation appear to be quite similar to the same biological processes in other mammals and the interaction of genes, hormones and body structures is fairly well understood. In the first weeks of life, a fetus has no anatomic or hormonal sex, and only a karyotype distinguishes male from female. Specific genes induce gonadal differences, which produce hormonal differences, which cause anatomic differences, leading to psychological and behavioral differences, some of which are innate and some induced by the social environment.

Humans, many mammals, insects and other animals have an XY sex-determination system. Humans have forty-six chromosomes, including two sex chromosomes, XX in females and XY in males. It is obvious that the Y chromosome must carry at least one essential gene which determines testicular formation (originally termed TDF). A gene in the sex-determining region of the short arm of the Y, now referred to as SRY, has been found to direct production of a protein, testis determining factor, which binds to DNA, inducing differentiation of cells derived from the genital ridges into testes. In transgenic XX mice (and some human XX males), SRY alone is sufficient to induce male differentiation.

Various processes are involved in the development of sex differences in humans. Sexual differentiation in humans includes development of different genitalia and the internal genital tracts, breasts, body hair, and plays a role in gender identification.[1]

The development of sexual differences begins with the XY sex-determination system that is present in humans, and complex mechanisms are responsible for the development of the phenotypic differences between male and female humans from an undifferentiated zygote.[2] Atypical sexual development, and ambiguous genitalia, can be a result of genetic and hormonal factors.[3]

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hypogonadism | pathology | Britannica.com

hypogonadism,in men, decreased testicular function that results in testosterone deficiency and infertility.

Hypogonadism is caused by hypothalamic, pituitary, and testicular diseases. Hypothalamic and pituitary diseases that may cause decreased testicular function include tumours and cysts of the hypothalamus, nonsecreting and prolactin-secreting pituitary tumours, trauma, hemochromatosis (excess iron storage), infections, and nonendocrine disorders, such as chronic illness and malnutrition. The primary testicular disorders that result in hypogonadism in postpubertal men include Klinefelter syndrome and related chromosomal disorders, although these disorders usually manifest at the time of puberty.

Other causes of hypogonadism in men include testicular inflammation (orchitis) caused by mumps; exposure to gonadal toxins, including alcohol, marijuana, and several anticancer drugs (e.g., cyclophosphamide, procarbazine, and platinum); and radiation with X-rays. Many of the disorders that cause delayed puberty are sufficiently mild that affected men do not seek care until well into adult life. This particularly applies to those disorders that decrease spermatogenesis and therefore fertility but spare Leydig cell function.

The clinical manifestations of hypogonadism in adult men include decreased libido, erectile dysfunction (inability to have or maintain an erection or to ejaculate), slowing of facial and pubic hair growth and thinning of hair in those regions, drying and thinning of the skin, weakness and loss of muscle mass, hot flashes, breast enlargement, infertility, small testes, and osteoporosis (bone thinning). The evaluation of men suspected to have hypogonadism should include measurements of serum testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin, in addition to the analysis of semen. Men with hypogonadism who have decreased or normal serum gonadotropin concentrations are said to have hypogonadotropic hypogonadism and may need to be evaluated for hypothalamic or pituitary disease with computerized axial tomography or magnetic resonance imaging (MRI) of the head. Men with hypogonadism who have increased serum gonadotropin concentrations are said to have hypergonadotropic hypogonadism, and their evaluation should be focused on the causes of testicular disease, including chromosomal disorders.

Men with hypogonadism caused by a hypothalamic disorder, pituitary disorder, or testicular disorder are treated with testosterone. Testosterone can be given by intramuscular injection or by patches or gels applied to the skin. Testosterone treatment reverses many of the symptoms and signs of hypogonadism but will not increase sperm count. Sperm count cannot be increased in men with testicular disease, although it is sometimes possible to increase sperm count in men with hypothalamic or pituitary disease by prolonged administration of gonadotropin-releasing hormone or gonadotropins. In men with testicular disease, viable sperm can sometimes be obtained by aspiration from the testes for in vitro fertilization.

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Emerging interactions between skin stem cells and their …

Hair follicle lineage and niche signals regulate hair follicle stem cells. (a) HFSCs can exist in two states. Quiescent bulge stem cells (Bu-SCs) are located in the outer layer of this niche and contribute to the generation of the outer root sheath. Primed stem cells reside in the hair germ, sandwiched between the bulge and a specialized dermal cluster known as the dermal papilla. They are responsible for generating the transit amplifying cell (TAC) matrix, which then gives rise to the hair shaft and its inner root sheath (IRS) channel. Although matrix and IRS are destroyed during catagen, many of the outer root sheath (ORS) cells are spared and generate a new bulge right next to the original one at the end of catagen. The upper ORS contributes to the outer layer of the new bulge, and the middle ORS contributes to the hair germ. Some of the lower ORS cells become the differentiated inner keratin 6+ (K6+) bulge cells, which provide inhibitory signals to Bu-SCs, raising their activation threshold for the next hair cycle. (b) During telogen, K6+ bulge cells produce BMP6 and FGF-18, dermal fibroblasts (DFs) produce BMP4 and subcutaneous adipocytes express BMP2. Together, these factors maintain Bu-SCs and hair germ in quiescence. At the transition to anagen, BMP2 and BMP4 are downregulated, whereas the expression of activation factors including noggin (NOG), FGF-7, FGF-10 and TGF-2 from dermal papillae and PDGF- from adipocyte precursor cells (APCs) is elevated. This, in turn, stimulates hair germ proliferation, and a new hair cycle is launched. Bu-SCs maintain their quiescent state until TAC matrix is generated and starts producing SHH.

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Stem cell controversy – Wikipedia, the free encyclopedia

The stem cell controversy is the consideration of the ethics of research involving the development, usage, and destruction of human embryos. Most commonly, this controversy focuses on embryonic stem cells. Not all stem cell research involves the creation, usage and destruction of human embryos. For example, adult stem cells, amniotic stem cells and induced pluripotent stem cells do not involve creating, using or destroying human embryos and thus are minimally, if at all, controversial.

The use of stem cells has been happening for decades. In 1998, scientists discovered how to extract stem cells from human embryos. This discovery led to moral ethics questions concerning research involving embryo cells, such as what restrictions should be made on studies using these types of cells? At what point does one consider life to begin? Is it just to destroy an embryo cell if it has the potential to cure countless numbers of patients? Political leaders are debating how to regulate and fund research studies that involve the techniques used to remove the embryo cells. No clear consensus has emerged. Other recent discoveries may extinguish the need for embryonic stem cells.[1]

Since stem cells have the ability to differentiate into any type of cell, they offer something in the development of medical treatments for a wide range of conditions. Treatments that have been proposed include treatment for physical trauma, degenerative conditions, and genetic diseases (in combination with gene therapy). Yet further treatments using stem cells could potentially be developed thanks to their ability to repair extensive tissue damage.[2]

Great levels of success and potential have been shown from research using adult stem cells. In early 2009, the FDA approved the first human clinical trials using embryonic stem cells. Embryonic stem cells can become all cell types of the body which is called totipotent. Adult stem cells are generally limited to differentiating into different cell types of their tissue of origin. However, some evidence suggests that adult stem cell plasticity may exist, increasing the number of cell types a given adult stem cell can become. In addition, embryonic stem cells are considered more useful for nervous system therapies, because researchers have struggled to identify and isolate neural progenitors from adult tissues[citation needed]. Embryonic stem cells, however, might be rejected by the immune system – a problem which wouldn’t occur if the patient received his or her own stem cells.

Some stem cell researchers are working to develop techniques of isolating stem cells that are as potent as embryonic stem cells, but do not require a human embryo.

Some believe that human skin cells can be coaxed to “de-differentiate” and revert to an embryonic state. Researchers at Harvard University, led by Kevin Eggan, have attempted to transfer the nucleus of a somatic cell into an existing embryonic stem cell, thus creating a new stem cell line.[3] Another study published in August 2006 also indicates that differentiated cells can be reprogrammed to an embryonic-like state by introducing four specific factors, resulting in induced pluripotent stem cells.[4]

Researchers at Advanced Cell Technology, led by Robert Lanza, reported the successful derivation of a stem cell line using a process similar to preimplantation genetic diagnosis, in which a single blastomere is extracted from a blastocyst.[5] At the 2007 meeting of the International Society for Stem Cell Research (ISSCR),[6] Lanza announced that his team had succeeded in producing three new stem cell lines without destroying the parent embryos. “These are the first human embryonic cell lines in existence that didn’t result from the destruction of an embryo.” Lanza is currently in discussions with the National Institutes of Health (NIH) to determine whether the new technique sidesteps U.S. restrictions on federal funding for ES cell research.[7]

Anthony Atala of Wake Forest University says that the fluid surrounding the fetus has been found to contain stem cells that, when utilized correctly, “can be differentiated towards cell types such as fat, bone, muscle, blood vessel, nerve and liver cells”. The extraction of this fluid is not thought to harm the fetus in any way. He hopes “that these cells will provide a valuable resource for tissue repair and for engineered organs as well”.[8]

The status of the human embryo and human embryonic stem cell research is a controversial issue as, with the present state of technology, the creation of a human embryonic stem cell line requires the destruction of a human embryo. Stem cell debates have motivated and reinvigorated the pro-life movement, whose members are concerned with the rights and status of the embryo as an early-aged human life. They believe that embryonic stem cell research instrumentalizes and violates the sanctity of life and is tantamount to murder.[9] The fundamental assertion of those who oppose embryonic stem cell research is the belief that human life is inviolable, combined with the belief that human life begins when a sperm cell fertilizes an egg cell to form a single cell.

A portion of stem cell researchers use embryos that were created but not used in in vitro fertility treatments to derive new stem cell lines. Most of these embryos are to be destroyed, or stored for long periods of time, long past their viable storage life. In the United States alone, there have been estimates of at least 400,000 such embryos.[10] This has led some opponents of abortion, such as Senator Orrin Hatch, to support human embryonic stem cell research.[11] See Also Embryo donation.

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Mutation – Wikipedia, the free encyclopedia

In biology, a mutation is a permanent change of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements. Mutations result from damage to DNA which is not repaired or to RNA genomes (typically caused by radiation or chemical mutagens), errors in the process of replication, or from the insertion or deletion of segments of DNA by mobile genetic elements.[1][2][3] Mutations may or may not produce discernible changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity.

Mutation can result in several different types of change in sequences. Mutations in genes can either have no effect, alter the product of a gene, or prevent the gene from functioning properly or completely. Mutations can also occur in nongenic regions. One study on genetic variations between different species of Drosophila suggests that, if a mutation changes a protein produced by a gene, the result is likely to be harmful, with an estimated 70 percent of amino acid polymorphisms that have damaging effects, and the remainder being either neutral or weakly beneficial.[4] Due to the damaging effects that mutations can have on genes, organisms have mechanisms such as DNA repair to prevent or correct (revert the mutated sequence back to its original state) mutations.[1]

Mutations can involve the duplication of large sections of DNA, usually through genetic recombination.[5] These duplications are a major source of raw material for evolving new genes, with tens to hundreds of genes duplicated in animal genomes every million years.[6] Most genes belong to larger families of genes of shared ancestry.[7] Novel genes are produced by several methods, commonly through the duplication and mutation of an ancestral gene, or by recombining parts of different genes to form new combinations with new functions.[8][9]

Here, domains act as modules, each with a particular and independent function, that can be mixed together to produce genes encoding new proteins with novel properties.[10] For example, the human eye uses four genes to make structures that sense light: three for color vision and one for night vision; all four arose from a single ancestral gene.[11] Another advantage of duplicating a gene (or even an entire genome) is that this increases redundancy; this allows one gene in the pair to acquire a new function while the other copy performs the original function.[12][13] Other types of mutation occasionally create new genes from previously noncoding DNA.[14][15]

Changes in chromosome number may involve even larger mutations, where segments of the DNA within chromosomes break and then rearrange. For example, in the Homininae, two chromosomes fused to produce human chromosome 2; this fusion did not occur in the lineage of the other apes, and they retain these separate chromosomes.[16] In evolution, the most important role of such chromosomal rearrangements may be to accelerate the divergence of a population into new species by making populations less likely to interbreed, thereby preserving genetic differences between these populations.[17]

Sequences of DNA that can move about the genome, such as transposons, make up a major fraction of the genetic material of plants and animals, and may have been important in the evolution of genomes.[18] For example, more than a million copies of the Alu sequence are present in the human genome, and these sequences have now been recruited to perform functions such as regulating gene expression.[19] Another effect of these mobile DNA sequences is that when they move within a genome, they can mutate or delete existing genes and thereby produce genetic diversity.[2]

Nonlethal mutations accumulate within the gene pool and increase the amount of genetic variation.[20] The abundance of some genetic changes within the gene pool can be reduced by natural selection, while other “more favorable” mutations may accumulate and result in adaptive changes.

For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly’s offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chance of this butterfly’s surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population.

Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual. These can accumulate over time due to genetic drift. It is believed that the overwhelming majority of mutations have no significant effect on an organism’s fitness.[citation needed] Also, DNA repair mechanisms are able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise-permanently mutated somatic cells.

Beneficial mutations can improve reproductive success.

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