Category Archives: Human Genetics

Heres what you need to know.

Kate HarloeJul. 28, 2017 1:35 PM

Ben Birchall/Associated Press

For the first known time in the United States, scientists used a gene-editing technique called CRISPR to modify early-stage human embryos, according to a report published Wednesday in MIT Technology Review.

Since the development several years ago ofCRISPR, a tool that allows scientists to change sequences of DNA within a cell, scientists have speculated about its potential to free families of genetic disease or stop the spread of other diseases like malaria, among other possibilities. But the technology also raises major ethical questions.

Heres a quick rundown of the latest breakthroughand how it could change the way we think about humanreproduction and, well, humans themselves.

How did the experiment work?

According to MIT Technology Reviews report, a team of researchers at Oregon Health & Science University, led by geneticist Shoukhrat Mitalipov, used CRISPR to correct disease-causing genes in human embryos. Its not yet clear whether these were viable embryosembryos that could, theoretically, grow into humans.

A wide range of diseaseslike Huntingtons, sickle-cell anemia, and Tay-Sachs, for exampleare caused by mutations in genes. Its also not clear what genes Mitalipov and his team edited in their experiment. But regardless, it appears that their study was successful in a couple ways: First, they reportedly edited a greater number of embryos than scientists had in previous studies. Second, Mitalipov and his team claim they did so without causing as manyerrors as previous scientists.

CRISPR has been used to edit human embryos a few times before; Chinese scientists did it in March. But in prior experiments, scientists ran into problems when CRISPR edits were taken up only by some of the cells in an embryo. This is called mosaicism:it means that the child that develops from the embryo could still inherit the disease that scientists tried to edit away.

According to MITs report, Mitalipov reduced the occurrence of mosaicism and seemed to largely avoid off-target edits (another kind of CRISPR error, wherein scientists accidentally alter a gene other than the one they aim to change).

Why is this important?

A couple reasons. First, its the only known attempt to use CRISPR to edit human embryos in the United States. More on the legality of that below.

Second, if this attempt really was successful, its big news for people whose families carry genetic disease. In theory, using this technique, scientists could edit not just our offspring, but our offsprings offspring. This is called human germline editing. When scientists edit the DNA in an embryo, the changes will theoretically be inherited by each successive generation, permanently fixing the germlinethe genetic inheritanceof a family.

This seems ethically complex.

Right. The ethics and laws surrounding human germline editingare murky. Scientists in favor of human germlinemodification often argue that the techniquewill help us reduce the occurrence of genetic diseases.

But criticsdisagree.This is just not needed for preventing inheritable disease, said Marcy Darnovsky, Executive Director of the Center for Genetics and Society. There are [other techniques that] can already be used safely to prevent the births of children with serious genetic diseases in almost every case. One example of such a technique is preimplantation diagnosis, commonly referred to as PGD, which allows parents to screen embryos for certain disease-causing genes before implanting them through in vitro fertilization (IVF). But its not always effectiveif someone carries two copies of a defective gene, for example, all their embryos would carry that gene, as well.

Darnovsky also worries about safety. Despite whatever the claims are about safety, [like] no mosaicism, we still dont know if that would mean its safe to create a new human being and anyone who tried it would be taking an enormous and unacceptable risk with that future persons life.

Another concern: Right now, scientists aresupposed to stick to editing disease-causing genes. But the technology opens up the possibility of editing genes for enhancementallowing parents to edit for certain kinds of physical and behavioral characteristics in their children. Darnovsky worries that this would usher in an era of genetic discrimination. That would be layering new forms of inequality and discrimination onto the ones we already live with, she said.

Is this legal?

Probably.In 2015, Congress passed a law forbidding the Food and Drug Administration from reviewing applications for germline editing of human embryos, meaning no clinical trials can move forward with FDA funding. We dont yet knowhow Mitalipov funded his project, but assuming it was funded privately, its perfectly legal.

That wouldnt be the case in many other countries. The Center for Genetics and Society reports that over 40 countries, including most with established biotech sectors, have established legal prohibitions on germline modification for human reproduction. An international treaty also prohibits it. The United States has no such policy.

Whats next?

Well know more once the study is released, but its worth noting that in February of this year, the National Academy of Sciences and the National Academy published a report that said human germline editing could be permitted in the future. It outlined criteria for germline editing, recommending that it only be used for disease prevention. The authors of the report wrote that editing for the enhancement of human traits and capacities should not be allowed at this time. But the report didnt eliminate the possibility of editing for enhancement in the future.

Reactions to the report were mixed. Some experts, like Darnovsky, feel that human germline modification should not be done for any purpose. But in an interview with Science, Eric Lander, president and founding director of MIT and Harvards Broad Institute, a genomics research center, said he thought the report struck the right balance of optimism and caution. They want to put friction tape on the slope so the slope isnt slippery, Lander said. Whether and for how long the tape will hold is an open question.

Mother Jones is a nonprofit, and stories like this are made possible by readers like you. Donate or subscribe to help fund independent journalism.

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US Scientists Just Edited a Human Embryo for the First Time. (Yes, People Are Freaking Out.) - Mother Jones

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The polygamous town facing genetic disaster BBC News That's because genetic information is useless on its own. To be meaningful to medical research, it must be linked to information about disease. In fact, more human disease genes have been discovered in Utah with its Mormon history than any other ...

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The polygamous town facing genetic disaster - BBC News

Scientists have found that a "ghost" lineage of archaic human may have interbred with the ancestors of modern humans in what is now sub-Saharan Africa around 200,000 years ago.

A protein that helps make human spit slimy reveals signs that the ancestors of modern humans interbred with an extinct human lineage that was an even more distant relation than Neanderthals, a new study finds.

The ancestors of modern humans once shared the world with ancient human lineages such as the Neanderthals, the closest extinct relatives of modern humans, as well as the Denisovans, which might have once roamed a vast range stretching from Siberia to Southeast Asia. In previous research, DNA extracted from fossilized bones and teeth of Neanderthalsand Denisovanshas revealed that the ancestors of modern humans interbred with both of these groups.

Previous research also suggested that the ancestors of modern humans may have interbred with other human lineages not known from the fossil record. For example, a 2011 studyanalyzing modern human DNA found that the species may have bred with a now-extinct lineage of humanity before leaving Africa. [Denisovan Gallery: Tracing the Genetics of Human Ancestors]

Now, researchers suggest that a "ghost" lineage of ancient humans may have contributed the DNA for a protein called mucin-7 found in the saliva of modern humansliving in sub-Saharan Africa today.

"About 5 to 7 percent of every population in sub-Saharan Africa has this divergent protein," said Omer Gokcumen, study co-senior author of the new study and an evolutionary genomicist at the University at Buffalo in New York.

The scientists were investigating mucin-7 in order to learn more about its role in human health. This molecule helps give saliva its slimy consistency and binds onto microbes, potentially helping rid the body of dangerous germs.

The researchers examined copies of the gene for mucin-7 the gene is called MUC7 in more than 2,500 modern human genomes. The scientists found that a number of genomes from sub-Saharan Africa possessed a version of the MUC7 gene that was wildly different from versions found in other modern humans. In fact, the Neanderthal and Denisovan versions of this gene more closely resembled those of other modern humans than this outlier did.

The researchers suggested the most plausible explanation for this mysterious version of the MUC7 gene is that it came from what they called a "ghost" lineage that is, one that scientists have not found the fossils of yet.

"We were not looking for this discovery we essentially stumbled onto it," Gokcumen told Live Science.

That this variant is so widespread across Africa suggests that it may have entered the modern human gene pool before the ancestors of modern humans separatedinto different regions across that continent, Gokcumen said. Given the usual rate at which genes mutate during the course of time, the researchers estimated the interbreeding event with this mystery lineage "may have happened about 200,000 years ago, but this lineage separated from the ancestors of modern humans maybe 500,000 years or 1 million years ago," Gokcumen added.

The scientists said they aren't sure how the variants of this protein might differ in function. "We do know that MUC7 has two major functions," said study co-senior author Stefan Ruhl, an oral biologist also at the University at Buffalo. "One is helping to lubricate the oral cavity for eating and swallowing, and the other, and this may be more important, is to let good microbes stay in the body and sort out the undesirable ones."

An analysis of mouth, skin, stool and other biological samples from 130 people revealed that different versions of MUC7 were strongly associated with different oral microbiomes the collections of microbes within the mouth. "This suggests that MUC7 is interacting with the oral microbiome and plays a role in terms of viruses, bacteria, parasites or fungi," Ruhl told Live Science. "On the other hand, we haven't ruled out that it may play a role in lubrication say, when it comes to environmental conditions such as dryness of the air."

Future research can explore when and where this interbreeding happened, "and if it happened just once or multiple times," Gokcumen said.

The scientists detailed their findingsonline July 21 in the journal Molecular Biology and Evolution.

Original article on Live Science.

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Human Ancestor Mated with 'Ghost Lineage' And the Proof Is in Your Spit - Live Science

Terence Capellini, an associate professor of human evolutionary biology, is co-author of new research revealing a genetic switch that changes the activity of a key skeletal gene related to height, and pinpoints a variant in the switch that favors shortness and is far more prevalent among Eurasian populations than expected.

The study, described in a July 3 paper in Nature Genetics, also points to a surprising link between the sequence that favors shortness and an increased risk of osteoarthritis.

There are a couple [of] aspects of this study that are interesting, Capellini said. One is that these genetic variants are occurring in noncoding sequences, so while genes are important, this shows that the genetic machinery around a gene can have a dramatic impact on how it works. But another interesting finding is that while evolution has increased the frequency of a variant that leads to decreased height, because of linked mutations, there is also an increased risk of osteoarthritis.

From the outset, the goal of Capellini and his colleagues wasnt to understand that link, but simply to better understand the genetics behind height variation.

To do so, the team from Harvard, Stanford, and the University of Waterloo in Ontario, Canada, combined the power of developmental biology, evolutionary genomics, and bioinformatics. The gene they chose to focus on, GDF5, has been linked repeatedly to height variation in genome-wide association studies.

This type of study has been done on upwards of 250,000 people, Capellini said. When you look at the results of these studies, this gene comes up again and again, and when you zoom in on the GDF5 region there are a lot of genetic variants that are also associated with height variation.

Essentially, Capellini said, those variations found in the noncoding regions around the gene can alter the activity of the gene in various areas in the body if they occur in specific genetic switches.

If you want to influence height, one place you want to turn on the gene is in the growth plates of bones, Capellini said. But the reality is that, for all the height studies that have been done, no one really knows the switches, let alone which one in the GDF5 region contains the actual DNA variant that causes the change in height.

To find it, the researchers attached a blue-producing reporter gene to each potential switch, and then tracked where the color was expressed in mouse embryos. What they found, he said, was a sequence that controls the activity of the gene in the growth plates, and, more importantly, a single DNA base change in the switch that influences its activity and height variation.

When Capellini and colleagues deleted the GDF5 growth plate switch from mice, their bones became shorter. This was in line with what the researchers saw when testing the human short height variant. Interestingly, they also saw that the femoral neck the connection between the femur and the femoral head grew shorter as well.

Other tests showed that the variant in favor of shorter height is prevalent among European and Asian populations, but rarely seen among African populations. Capellini and his colleagues suggest that this may be due to several factors:

We argue that shorter height may have been advantageous in the past because if you were living in a colder climate, having a short, stocky body may actually help you survive, he said. When you look at animals that reside in the Arctic, they tend to have shorter appendages to reduce the risk of frostbite and to maintain body heat.

However, given the effect of the switch on femoral neck length, Capellini and Stanfords David Kingsley also suggest, If youre tall and you have a long femoral neck, youre at higher risk for hip fracture So the thinking is that a shorter femoral neck might also have been a protective mechanism thats brought this sequence to very high frequency in some populations.

Its a very interesting situation, because favorable selection during human history means the variant we are studying is now present in literally billions of people, said Kingsley, a professor of developmental biology and co-leader of the study.

The growth switch wasnt the only one Capellini, Kingsley, and colleagues found.

The variant that decreases height is lowering the activity of GDF5 in the growth plates, but there are lots of other mutations that are physically linked to it, Capellini said. A few others occur in different switches we found, each of which turn GDF5 on in the joints, and these mutations are associated with hip and knee osteoarthritis risk, and likely lower GDF5 activity in the joints.

While the study offers new insight into the roles of noncoding DNA and the complex relationship between height and arthritis, Capellini stressed that GDF5 is only one gene of many that play a role in height, and that more work needs to be done to get a fuller picture.

We know the genetics of height and arthritis are complex, with potentially thousands of genes involved, he said. This makes us appreciate that biology is highly complex and we need to tease out more of these relationships to really get a sense of how one feature may be associated with another.

The research was supported with funding from the Natural Sciences and Engineering Research Councilof Canada, the Arthritis Foundation, the National Institutes of Health, the William F. Milton Fund of Harvard, the China Scholarship Council, and the Jason S. Bailey Fund of Harvard.

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New insight on height, arthritis - Harvard Gazette

Dive Brief:

Just two quarters after taking over as CEO at Biogen, Michel Vounatsos says he intends to make the company the "fastest-growing large-cap biotech."The new exec hopes to diversify Biogen's pipeline beyond the current MS franchise and the Alzheimers disease candidate aducanumab, which currently represents its largest pipeline opportunity or risk, if it should fail.

During an earnings call on July 25, Biogen laid out a plan to shift resources back to its base neuroscience franchise; something it moved away from for several years under previous CEO George Scangos.

Biogen intends to redirect about $400 million annually by 2019 toward R&D and "commercial value creation opportunities,"by "unlocking resources"within the portfolio.

"We believe our strategy will help support a healthy, resilient MS business for Biogen,"said Vounatsos, who also touted the overall performance of its new SMA drug Spinraza and highlighting its value to the company.

"Overall, we believe Spinraza will become one of our largest commercial assets, shifting the center of gravity for Biogen beyond MS to generate new growth,"he added.

On the call, Biogen execs said Spinraza will be a model for the types of drugs and deals the company wants to pursue. (Spinraza was developed through a deal with Ionis.)

Vounatsos also cited a recent deal with Bristol-Myers Squibb as the type of "growth-driving"deal that the company wants to replicate.In April, Biogen picked up a Phase 2-ready drug for Alzheimers disease and progressive supranuclear palsy from Bristol-Myers for $300 million upfront and the promise of $410 million in milestones.

While the company intends to retain its leadership position in MS, it hopes to move into other areas of neuroscience through both R&D and business development.

"We plan to maximize our performance in the near-term, while focusing on growth in the future,"said Vounatsos, who pointed to four key areas including MS, Alzheimers disease, Parkinsons disease and SMA. He also noted that pain, ophthalmology, neuropsychiatry and acute neurology would be tangential areas of interest.

"Biogen has a long history in neurology and has built up substantial core competencies in the area. It is our belief that no other area of medicine holds as much promise, with as much need, as neuroscience,"said EVP of R&D Mike Ehlers on the call.

"The opportunity space is vast and the time is right. With an ongoing revolution in basic neurobiology, human genetics, biomarkers, patient stratification and neural imaging, as well as increasing receptivity to clinical endpoints and regulatory paths, we believe that all signs point to neuroscience as the next oncology. Yet, for most companies, it is either not an area of focus or represents an opportunistic play. Our view is that success in neuroscience requires intense focus and that opportunistic approaches will not maximize value. There is a need for a leader in neuroscience. Our goal is to be that leader,"he added.

Top image credit: Dollar Photo Club

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Biogen: 'Our goal is to be that leader' - BioPharma Dive

I was a little surprised to see Ethical Issues in Fecal Microbiota Transplantation festooning the cover of the May issue of The American Journal of Bioethics not their typical topics of gene editing and testing, stem cells, and medical matters of life or death. But as fecal transplants become more medically accepted, questions of access and quality control are indeed arising. So here are a few scintillating facts about borrowing bowel microbiomes to combat dysbiosis.

1. The only sort-of approved use of FMT is for recurrent infection with Clostridium difficile, which causes severe diarrhea. The infection is usually acquired in a health care facility. A 2013 FDA enforcement discretionruling allows doctors to provide FMT without filing an Investigational New Drug Application but only to treat C. diff infection (CDI). Its 90% effective! The procedure is in clinical trials for other indications, albeit against a backdrop of widespread DIYvariations on the theme.

2. The procedure may become frontline treatment for CDI, not just a last resort when antibiotics have failed to control the terrifying torrents of watery stool. And its needed. Results of a study reported in the Annals of Internal Medicine found that cases of multiply recurrent CDI more than two bouts in a short time period are increasing at more than four times the rate of the infection in general. The numbers are daunting: up to half of the 500,000 people in the US who get CDI annually get it again at least once, for a total cost exceeding $5 billion a year. Drug resistant strains are arising and new drugs are coming on the market, but a fecal transplant may be the way to go from the get-go. CDI, say many whove had it, is far worse than overcoming the ick factor of receiving a bit of foreign poop.

3. Some medical organizations and insurers (including Medicare) cover fecal transplants for CDI.

4. Whats in a bowel movement? From 25 percent to54 percentof the solid portion after removing the 75 percent thats water consists of bacteria. The rest is undigested nutrients, electrolytes, and mucus, with color from bile pigments and odor from bacterial compounds (phenols, indole, skatole, ammonia, and hydrogen sulfide). But stool composition varies daily in individuals, which will complicate standardizing transplants. It also presents an obstacle to using a microbiome profile as a form of identification. One bioethicist mentioned checking stool at airports to see whether travelers have come from countries banned from immigration. Would a passport from a Swede be accepted if her feces harbor bacteria native to Somalia?

5. Fecal transplants may conjure mental images of turkey basters, but the material is delivered via enema, colonoscope, nasogastric tube (a nose hose), or capsule.

6. The technology is at least 1,700 years old. The first recorded use was in4th century China by a physician, Ge Hong, to treat food poisoning and diarrhea. In various times and places, poop has been delivered as yellow soup to humans and other animals (especially cattle) and German soldiers reportedly infused camel feces to treat bacterial diarrhea during World War I.

7. Reductionists attempting to drill down to the good stuff in a turd and then recreate it note that just part of a microbiome need be transferred, akin to a keystone organism in an ecosystem. Seres Therapeutics SER-109a capsule that delivers an ecology of bacterial spores enriched and purified from healthy, screened human donors is in phase 3 clinical trials to treat CDI. More mysterious is SER-262 the first synthetically-derived and designed microbiome therapeutic. It fared well against placebo in a 24-week phase 1 randomized controlled clinical trial.

8. Researchers are hard at work describing the optimal feces donor. Most references cite the Amsterdam protocolin this regard. And the American Gastroenterological Association maintains a National FMT Registrytomonitor adverse events and the details of donors. Will we one day have poop centers much like frozen yogurt shops where a hopeful recipient can order up a particular fecal microbiome? Or even mix flavors?

9. Altering the intestinal microbiome might treat autism, Parkinsons disease, depression, and anxiety, perhaps by affecting serotonin levels, thanks to the gut-brain axis.In an intriguing experiment, stool from people with major depressive disorder had a different effect on depression-like behaviors when transplanted into germ-free mice compared to the rodents more spirited response to stool from happy humans.

10. Should people pay for poop, like they do for sperm? Should we patent exceptionally healing donations? Anyone remember The Repository for Germinal Choice, an ill-fated California sperm bank for Nobel-prizewinners?

11. Delivery. Once feces donations are standardized, how will they be prepared and shipped? Dried out like sea monkeys? Fedex? UPS? Amazon Prime?

12. Should informed consent for a recipient include knowing the donors diet? Would a transplant from a person who ate pork be like implanting pig heart valves into an orthodox Jewish person? Might a recipient request a vegan donor?

13. OpenBiomeis a nonprofit stool bank that sends frozen matter to hospitals. Founded by a relative of someone who fought CDI futilely with seven rounds of vancomycin before a transplant helped, the company pays $40 for donating several times a week for two months. Stool must pass two rounds of screening, and the original owner must be aged 18-50, have a BMI under 30, and live nearCambridge, MA, where donations are deposited. The homepage opens to an image of clean, white bottles countering the ick factor is a big challenge for this emerging industry.

14. Fecal transplantation may have unexpected effects, especially since standardizing it as a medical substance is so challenging. The first noted was obesity, which is sort of obvious, but one man who had alopecia since age 6 had a transplant to treat CDI and grew so much hair that he had to shave!

15. AdvancingBiotreats private payers. Prep costs $115 and delivery depends on the route: esophagogastroduodenoscopy (down the hatch) is $307 and colonoscopy $341 to $591. The become a donor page shows 10 smiling people, most of them millennials. Those willing to sell their excrement must be between the ages of 18 and 65, have a BMI under 35, provide a medical history, and have a blood test for infections, including cholera, E. coli, plague, foodborne Salmonella and Shigella, as well as various eggs and larvae. Presumably the donation must score a healthy type 3 or 4 on the Bristol Stool Chart.

Stay tuned. Scatological jokes aside, fecal transplantation is a valid medical procedure that will likely continue to find new niches.

Ricki Lewis has a PhD in genetics and is a genetics counselor, science writer and author of Human Genetics: The Basics. Follow her at her website or Twitter @rickilewis.

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15 facts about fecal transplants The straight poop - Genetic Literacy Project

CLEMSON With patches of exposed skin, large lesions across her face and dull, expressionless eyes, you might think Lorelei, a Shetland sheepdog, has been abused. But that would be far from the truth: Lorelei is loved and well cared-for. She suffers from a painful condition called dermatomyositis, a genetic skin disorder that affects dogs and humans.

Lorelei, a Shetland sheepdog living in France, became the poster dog for dermatomyositis. The disease caused painful lesions on her face, feet, ears and tail when she was a puppy, as seen in this photo.

The discovery, by Leigh Anne Clark, an associate professor of genetics at Clemson University, and her colleagues, could improve the future for dogs with dermatomyositis. The findings could also give scientists clues into the genetic variations of the 10 in 1 million people who have the disease.

The results from our study can be used as a tool for dog breeders to prevent the disease from affecting puppies, while preserving desirable traits and genetic variation within the breed. Using this new resource, even a dog with dermatomysitis can produce healthy puppies with a mate having a compatible genotype, said Clark.

Before their latest study, Clark and her colleagues were aware of several factors that indicated the disease is multifactorial, deriving from a combination of genetic and environmental effects.

Clark is developing a genetic test for breeders that will tell them the risk of a dame and a sire having puppies with dermatomyositis.

In dogs, dermatomyositis is seen almost exclusively in collie and Shetland breeds. A hereditary disorder will only affect certain breeds, whereas a non-genetic disorder should affect all dog breeds at the same frequency, so Clark knew the disease had a genetic basis.

Her team also recognized that the condition is a complex disorder involving several genetic components as opposed to a simple dominant or recessive disorder because of a wide range of characteristics, or phenotypes, that appear in affected dogs. And they knew that dermatomyositis involved genetic changes in the major histocompatibility complex, which functions in immune defense.

Clark also suspected that an environmental component often triggers onset of the disease because many dog owners reported the animals were under stress when the disease first appeared.

The team used genetic analyses from more than 160 dogs around the world, including Lorelei, who lives in France. Then they conducted a genome-wide association study, or GWAS, to compare genetic variants present in dogs that are affected and unaffected to determine which genetic changes are exclusive to affected dogs. GWAS allowed them to identify an association between a genetic variant and the disease phenotype.

The results displayed a very strong correlation between the dermatomyositis phenotype and variants on chromosomes 10 and 31, suggesting that risk variants for dermatomyositis were located on those chromosomes.

I remember when we saw [the results]. We were speechless. We started looking at the genotypes and writing them down, and it was exciting, said Clark.

Due to the complexity of dermatomyositis, Clark suspects that the genetic variants are working in conjunction to produce the disease. This is known as an additive effect, wherein multiple genetic influences combine to produce the disease phenotype.

Human juvenile dermatomyositis and canine dermatomyositis display similar symptoms and clinical expressions; they are both vasculopathies, affecting connective tissues. Clark hopes her research can be applied to identify risk alleles in humans.

Although this study is a breakthrough in understanding the genetic basis of dermatomyositis, Clark believes there is a lot more to learn about the disease. Future research will focus on dogs with moderate-risk genotypes, specifically asking why some moderate-risk dogs express the disease and others do not. Clark and her team also have a grant with the Collie Health Foundation to investigate moderate risk genotypes.

When Clark was growing up in Texas she worked for a Shetland breeder, an experience that fueled her love of dogs, taught her about breeding techniques and introduced her to genetics. She began researching dermatomyositis in 2004 as a postdoctoral fellow at Texas A&M University, but the work hit a dead end. Clark returned to the project several years later at Clemson, following the invention of new genetic techniques. She received funding to investigate the genetic basis of dermatomyositis in 2010.

Clarks work will help breeders accurately identify which dogs to pair for breeding. By understanding the genetic risks, breeders can selectively mate the dogs to reduce the disease in the population.

Eventually, Clark thinks the disease could be bred out of dogs, leaving collies and Shetlands like Lorelei to be models for good behavior and beauty, and not for a genetic disorder.

END

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Dogged genetics research identifies genes associated with skin disorder - Clemson Newsstand

Scientists have found out why dogs are genetically predisposed to be the mans best friend. Three genes in dogs made themfriendly and socially inhibited, which makes them behave differently towards people than wolves do.

Dogs are terribly obsessed with being close to people. They are basically incredibly social wolves, thanks to these genes. However, according to scientists, the genes thatmake dogs super social can also be present in humans who have the Williams-Beuren syndrome. This study was published on July 19 in the journal Science Advances.

Everyone wants to find the genes that make dogs different from wolves, and try to understand how domestication changed the genome, said Bridgett von Holdt, who studies canine genetics at Princeton University.

Scientists from the Princeton University and Oregon State University wanted to find out what makes dogs and wolves behave that different. They chose 18 dogs and 10 gray wolves to make some behavioral tests, which included sociability and problem-solving exercises. They found out that dogs have a structural variation in 3 of the genes on chromosome 6 that could explain why dogs are so social and so fond of human beings. These three genes are called GTF2I, GTF2IRD1, and WBSCR17. According to lead authors, similar social behaviors can be seen in mice.

VonHoldt said that dogs tend to look more at humans than wolves do. As well, dogs are less independent in problem-solving tests when theyre around humans. When they are close to a person, their affinity remains for the rest of their lives. It might be what scientists call the domestication syndrome, which they have noticed in other animals. However, what astonishes scientists is how the genetic change occurs.

Many dogs maintain their puppy-like enthusiasm for social interactions throughout their life, whereas wolves grow out of this behavior and engage in more mature, abbreviated greetings as they age, said Monique Udell, who studies animal behavior at Oregon State University and co-authored the new study. One might think of how a young child greets you versus a teenager or adult relative.

During the behavioral tests, dogs had to open a puzzle box that had a hidden sausage inside. Only 2 out of 18 dogs opened the box regardless of the presence of a human. Wolves did a better job. Eight of 10 wolves completed this task successfully when a human was there with them, and nine opened when they were alone.

On the other hand, when dogs were with a person, they spent more time looking at the person than looking at the puzzle box; but wolves didnt mind about the person, they spent 100 percent of the time watching the box, forgetting that the human was there with them. Udell says that it was what they expected because dogs are distracted by social stimulation.

Another test consisted of evaluating how much time the animals spent within 1 meter from a person. This experiment was carried out in 4 phases. In the first, astranger sat on a chair making no eye contact with the creatures. In the second one, the same stranger actively engaged with the canine. The third and the four rounds were almost the same as the two first; the difference was that the person who sat was the animals owner or caretaker, instead of a complete stranger.

According to the results, dogs and wolves prefer to be close to people they know. Dogs spent a median of 93 percent of their time near people while wolves spent only 3 percent of theirs. With the strangers, dogs spent 53 of the time close to them while wolves spent 28 percent. This difference is not that dramatic.

Scientists also explain that dogs and humans could have similar genes. The same chromosomal mutation that makes a dog be so friendly and hyper social is linked to a rare disorder in humans, the Williams-Beuren Syndrome, or WBS. One of the symptoms of this condition is that people lack social inhibition making them terribly outgoing and trusting.

People with the Williams-Beuren Syndrome are also very social, and they tend to bond quickly with other people no matter if they are complete strangers. However, other symptoms include difficulty to learn and cardiovascular problems.

In fact, von Holdt started knowing this similarity between dogs and humans. On 2010, von Holdt had explained the entire genome of 225 gray wolves and 912 dogs from 85 breeds. There were clear differences between the genes of dogs and wolves, especially when it came to the WBS gene, WBSCR17. However, she wasnt entirely clear about how affected the behavior of dogs.

Three years ago, she began working with Udell who had developed behavioral data of dogs. Then, putting together elements of both research they were able to find the missing link.

Source: Los Angeles Times

Originally posted here:
Dogs are genetically predisposed to be the man's best friend - Pulse Headlines

Photo Credit: Anatolii Brohovskyi / Shutterstock.com

Dogs were the first animal to cohabit with humans, and modern research increasingly reveals the many ways in which humans and dogs have grown in tandem for thousands of years. New research out this week reveals that has likely been the case since the Early Neolithic period in ancient Europe, which dates the canine-human relationship back much further than previously theorized. New DNA research published this week in the journal Nature Communications shows modern dogs likely came from a single pack of wolves between 20,00040,000 years ago in Eurasia.

While previous studies suggested there may have been two separate instances of wolf domestication, the new study notes that most dogs of today can be traced back to a single Ancient European dog genome. While the study narrows the origins of dogs down to a 20 thousand year period, the exact location and timing remains a mystery.

Science has shown that the relationsihp between dogs and humans has always been a mutual one, and our ancient ties likely began because of a few hungry and particularly friendly wolves.

Here are three key scientifictheories about dog-human co-evolution:

1. A genetic mutation made some wolves (and dogs) want to cuddle with us and be our friends.

Dogs like to stay closer to humans and gaze at us longer than wolves do, a new study of canine genetics at Princeton University observed. And, the likelihood of an animal doing this correlates with that animal's given DNA.

As an article in the LA Times about the new study notes, similar genetic mutations in humans are linked with a rare developmental disorder called Williams-Beuren Syndrome (WBS).

People with WBS are typically hyper-social, meaning they form bonds quickly and show great interest in other people, including strangers, the Times piece notes.

In the study, researchers found that the more social dogs and wolves had similar mutations in three genes called GTF2I, GTF2IRD1 and WBSCR17. Those same genes have been observed in other studies to cause increased social behavior in mice and are thought to do the same thing in humans.

2. Dogs probably domesticated us, not the other way around.

Some scientists theorize that friendly wolves sought out humans. They probably made the first move in our thousands-of-years-old relationship, as a 2013 National Geographic feature details.

The article explains that the theory that humans used dogs to hunt doesnt hold much water because humans were already successful hunters without wolves, and didnt tend to be friendly towards other carnivorous species. It theorizes that friendly wolves likely made the first move, and sought out human relationships:

The wolves that were bold but aggressive would have been killed by humans, and so only the ones that were bold and friendly would have been tolerated.

Over time the physicality of those friendlier wolves changed.

Domestication gave them splotchy coats, floppy ears, wagging tails. In only several generations, these friendly wolves would have become very distinctive from their more aggressive relatives.

3. Dogs and humans ate together as we evolved, so our digestion has developed similarly.

As researchers on a 2013 study of dog genetics explain, there are a number of corresponding genes in dogs and humans particularly when it comes to processing food.

In both of our species, the genes responsible for metabolism and digestion, such as the genetic code for cholesterol, changed similarly. Researchers theorized those changes could be due to dramatic changes in the proportion of plants vs meats dogs and humans were consuming around the same time.

April M. Short is a yoga teacher and writer whopreviouslyworked as AlterNet's drugs and health editor. She currently works part-time for AlterNet, and freelances for a number of publications nationwide.

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3 Things You Probably Didn't Know About Humans' Ancient Relationship with Dogs - AlterNet

Ancient Greek DNA from Euboea and Corinth still present in populations in the region

Paestum, Salerno, Italy, Temple Of Athena, Magna Grecia.

No one questions the colonisation of Magna Graecia by the Greeks, the name given to the coastal areas of Southern Italy and Sicily, is proof of that. It was in the 8th century BC that Ancient Greeks came decided to settle in the fertile lands of Magna Graecia, according to artefact and other archaeological finds. New DNA research published in the European Journal of Human Genetics, has just confirmed there is a strong biological influence apart from the cultural. Scenarios ranging from a colonization process based on small groups of males moderately admixing with autochthonous [indigenous] groups... to substantial migrations from Greece and a Hellenic origin for a significant part of the pre-Roman Italian population, explains Lead author Sergio Tofanelli. Tofanelli and his colleagues find fault with previous DNA analyses of Greek colonisation primarily which were using specific lineages of haplotypes as markers, however, contemporary genomes in many cases do not accurately reflect the DND makeup of ancient populations. Using both mitochondrial DNA and Y chromosome analysis, the study simulates genetic change over time sequencing the DNA of more than 800 people native to the areas of Euboea and Corinth, where the first wave of Magna Grecia colonisers came from, along with people whose families were native to Sicily and southern Italy.

By modelling the typical mutation rate they recovered a strong signature of Greek DNA between the 8th and 5th centuries BC. "Despite the multiple alternative explanations for historical gene flow," they write, "it is relevant to stress here that a signature specifically related to the Euboea island in East. Sicily was consistently found at different levels of analysis-proving that it was most likely colonised first, in line with the historical and archaeological evidence, attesting to an extended and numerically important Greek presence in this region." Tofanellis finds point that "the migration and settlement process was driven by males. This is one of the few cases of sex-biased gene flow skewed towards an increased male instead of female contribution," the authors conclude. Part of the reason could be due to patrilocality as the norm for men was to stay in their birthplace while women could be offered to spouses in neighbouring kingdoms. This study is the first to use a full set of haplotypes and therefore provides better coverage of possible DNA links than previous studies.

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New research proves Greeks colonised Sicily and Southern Italy - Neos Kosmos