marmoset-sequence-sheds-light-on-primate-biology-evolution

Marmoset Sequence Sheds Light on Primate Biology, Evolution

A team of scientists from around the world led by Baylor College of Medicine and Washington University in St. Louis has completed the genome sequence of the common marmoset – the first sequence of a New World Monkey – providing new information about the marmoset’s unique rapid reproductive system, physiology and growth, shedding new light on primate biology and evolution. The team published the work today in the journal Nature Genetics.

“We study primate genomes to get a better understanding of the biology of the species that are most closely related to humans,” said Dr. Jeffrey Rogers, associate professor in the Human Genome Sequencing Center at Baylor and a lead author on the report. “The previous sequences of the great apes and macaques, which are very closely related to humans on the primate evolutionary tree, have provided remarkable new information about the evolutionary origins of the human genome and the processes involved.”

With the sequence of the marmoset, the team revealed for the first time the genome of a non-human primate in the New World monkeys, which represents a separate branch in the primate evolutionary tree that is more distant from humans than those whose genomes have been studied in detail before. The sequence allows researchers to broaden their ability to study the human genome and its history as revealed by comparison with other primates. ”Each new non-human primate genome adds to a deeper understanding of human biology,” said Dr. Richard Gibbs, director of the Human Genome Sequencing Center at Baylor and a principal investigator of the study.

Read the full article here.

Friends Share Genetic Similarities

If you consider your friends family, you may be on to something. A study from the University of California, San Diego, and Yale University finds that friends who are not biologically related still resemble each other genetically.

Published in the Proceedings of the National Academy of Sciences, the study is coauthored by James Fowler, professor of medical genetics and political science at UC San Diego, and Nicholas Christakis, professor of sociology, evolutionary biology, and medicine at Yale. “Looking across the whole genome,”

The study is a genome-wide analysis of nearly 1.5 million markers of gene variation, and relies on data from the Framingham Heart Study. The Framingham dataset is the largest the authors are aware of that contains both that level of genetic detail and information on who is friends with whom. The researchers focused on 1,932 unique subjects and compared pairs of unrelated friends against pairs of unrelated strangers. The same people, who were neither kin nor spouses, were used in both types of samples. The only thing that differed between them was their social relationship.Fowler said, “we find that, on average, we are genetically similar to our friends. We have more DNA in common with the people we pick as friends than we do with strangers in the same population.”

The findings are not, the researchers say, an artifact of people’s tendency to befriend those of similar ethnic backgrounds. The Framingham data is dominated by people of European extraction. While this is a drawback for some research, it may be advantageous to the study here: because all the subjects, friends and not, were drawn from the same population. The researchers also controlled for ancestry, they say, by using the most conservative techniques currently available. The observed genetic go beyond what you would expect to find among people of shared heritage– these results are “net of ancestry,” Fowler said.

Read the full article here.

Running For Life: How Speed Restricts Evolutionary Change of the Vertebral Column

One of the riddles of mammal evolution explained: the strong conservation of the number of trunk vertebrae. Researchers of the Naturalis Biodiversity Center and the University of Utah show that this conservation is probably due to the essential role of speed and agility in survival of fast running mammals. They measured variation in vertebrae of 774 individual mammal skeletons of both fast and slow running species. The researchers found that a combination of developmental and biomechanical problems prevents evolutionary change in the number of trunk vertebrae in fast running and agile mammals. In contrast, these problems barely affect slow and sturdy mammals. The study will appear on 14 July 2014 in PNAS.

Read the full article here.

U.S. Researchers Call for Greater Oversight of Powerful Genetic Technology

In 2011, experiments that allowed the potentially deadly H5N1 flu virus to spread between mammals ignited intense discussions about whether such research should be done at all, much less published. But most of the debate occurred after the research had been carried out. Kenneth Oye, a social scientist at the Massachusetts Institute of Technology in Cambridge, thinks that the discussion needs to take place before the lab work starts. In an article appearing online today in Science, he and nine colleagues have outlined what they think needs to be done about an emerging technology called gene drive.

Gene drive involves stimulating biased inheritance of particular genes to alter entire populations of organisms. It was first proposed more than a decade ago, and researchers have been developing gene drive approaches to alter mosquitoes to slow the spread of malaria and dengue fever. Although progress has been quite slow, recent advances in gene editing could lead to a rapid application of gene drive approaches to other species, Oye and his colleagues predict. To avoid a repeat of the H5N1 brouhaha, Oye says, “what we would really like to see is good, well-informed discussion of the benefit and potential risks specific to the particular application, species, and context. … We need to do it before people get that hot about it.”

Oye is not alone in calling for government agencies, scientists, and the general public to figure out how to regulate the release of mosquitoes and other organisms with gene drive alterations. In June, the WHO Special Programme for Research and Training in Tropical Diseases issued guidelines for evaluating genetically modified mosquitoes. A year earlier, the European Food Safety Authority came out with a six-step protocol for environmental assessments of all genetically modified organisms. “People are beginning to think through these issues,” says Austin Burt, an evolutionary geneticist at Imperial College London. Introducing these genetically modified mosquitoes into the wild should, over time, cause the modified gene to spread throughout the population and interrupt malaria transmission. He and researchers at about 10 institutions are working on the idea, but he says they are at least 5 years from testing it in the field.

Read the full article here.

Chimp Intelligence “Runs In Families,” Environment Less Important, Study Finds

A chimpanzee’s intelligence is largely determined by its genes, while environmental factors may be less important than scientists previously thought, according to a Georgia State University research study. The study found that some, but not all, cognitive, or mental, abilities, in chimpanzees depend significantly on the genes they inherit. The findings are reported in the latest issue of Current Biology.

“Intelligence runs in families,” said Dr. William Hopkins, professor in the Center for Behavioral Neuroscience at Georgia State and research scientist in the Yerkes National Primate Research Center at Emory University. “The suggestion here is that genes play a really important role in their performance on tasks while non-genetic factors didn’t seem to explain a lot. So that’s new.”

The role of genes in human intelligence or IQ has been studied for years, but Hopkins’ study is among the first to address heritability in cognitive abilities in nonhuman primates. Studies have shown that human intelligence is inherited through genes, but social and environmental factors, such as formal education and socioeconomic status, also play a role and are somewhat confounded with genetic factors.  Chimpanzees, which are highly intelligent and genetically similar to humans, do not have these additional socio-cultural influences. “We wanted to see if we gave a sample of chimpanzees a large array of tasks,” he said, “would we find essentially some organization in their abilities that made sense. The bottom line is that chimp intelligence looks somewhat like the structure of human intelligence.”

In the future, Hopkins wants to continue the study with an expanded sample size. He would also like to pursue studies to determine which genes are involved in intelligence and various cognitive abilities as well as how genes are linked to variation in the organization of the brain.

Hopkins also would like to determine which genes changed in human evolution that allowed humans to have such advanced intelligence.

Read the full article here.

Fair Game?: Eric Vilain at TEDxUCLA

ISG director, Eric Vilain, recently gave a provocative TEDx talk on Sports, Genes and Fairness, at the very heart of Society and Genetics matters. Feel free to share and post anywhere, and enjoy!

http://youtu.be/nu9GnW4HD18

Genetic Basis for Distinct Type of Autism Uncovered

A variation in the CHD8 gene has a strong likelihood of leading to a type of autism accompanied by digestive problems, a larger head and wide-set eyes. “We finally got a clear-cut case of an autism-specific gene,” said Raphael Bernier, University of Washington associate professor of psychiatry and behavioral sciences and clinical director of the Autism Center at Seattle Children’s. He is one of the lead authors of a Cell paper published today, “Disruptive CHD8 Mutations Define a Subtype of Autism in Early Development.

Today’s discovery is part of an emerging approach to studying the underlying mechanisms of autism and what those mean for people with the condition. Many research teams are trying to group subtypes of autism based on genetic profiles. The approach could uncover hundreds more genetic mutations. Genetic testing for the various forms eventually could be offered to families to guide them on what to expect and how to care for their child.

“This will be a game changer in the way scientists are researching autism,” he said. In the short term, Bernier said, clinicians can pay attention to the small population with this CHD8 mutation and provide targeted treatment.

Read the full article here. 

To Avoid Interbreeding, Monkeys Have Undergone Evolution in Facial Appearance

Old World monkeys have undergone a remarkable evolution in facial appearance as a way of avoiding interbreeding with closely related and geographically proximate species, researchers from New York University and the University of Exeter have found. Their research provides the best evidence to date for the role of visual cues as a barrier to breeding across species.

“Evolution produces adaptations that help animals thrive in a particular environment, and over time these adaptations lead to the evolution of new species,” explains James Higham, an assistant professor in NYU’s Department of Anthropology and the senior author of the study, which appears in the journal Nature Communications. “A key question is what mechanisms keep closely related species that overlap geographically from inter-breeding, so that they are maintained as separate species. Our findings offer evidence for the use of visual signals to help ensure species recognition: species may evolve to look distinct specifically from the other species they are at risk of inter-breeding with. In other words, how you end up looking is a function of how those around you look. With the primates we studied, this has a purpose: to strengthen reproductive isolation between populations.”

To do this, they photographed nearly two dozen species of guenons in various settings, over an 18-month period: in zoos in the United States and the United Kingdom and in a wildlife sanctuary in Nigeria. Armed with more than 1,400 standardized photographs, the researchers employed what is known as the eigenface technique, which has been used in the field of computer vision for machine recognition of faces, in order to distinguish primate features and then to determine whether the appearance of each guenon species was related to the appearance of other species.

Their results showed that, as predicted, the face patterns of guenon species have evolved to become more visually distinctive—specifically from those guenon species they overlap with geographically—and hence those that they are risk of hybridizing with.

Read the full article here.