Links for Keyword: Genes & Behavior

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By ANDREW POLLACK In the late 1980s, scientists at Osaka University in Japan noticed unusual repeated DNA sequences next to a gene they were studying in a common bacterium. They mentioned them in the final paragraph of a paper: “The biological significance of these sequences is not known.” Now their significance is known, and it has set off a scientific frenzy. The sequences, it turns out, are part of a sophisticated immune system that bacteria use to fight viruses. And that system, whose very existence was unknown until about seven years ago, may provide scientists with unprecedented power to rewrite the code of life. In the past year or so, researchers have discovered that the bacterial system can be harnessed to make precise changes to the DNA of humans, as well as other animals and plants. This means a genome can be edited, much as a writer might change words or fix spelling errors. It allows “customizing the genome of any cell or any species at will,” said Charles Gersbach, an assistant professor of biomedical engineering at Duke University. Already the molecular system, known as Crispr, is being used to make genetically engineered laboratory animals more easily than could be done before, with changes in multiple genes. Scientists in China recently made monkeys with changes in two genes. Scientists hope Crispr might also be used for genomic surgery, as it were, to correct errant genes that cause disease. Working in a laboratory — not, as yet, in actual humans — researchers at the Hubrecht Institute in the Netherlands showed they could fix a mutation that causes cystic fibrosis. But even as it is stirring excitement, Crispr is raising profound questions. Like other technologies that once wowed scientists — like gene therapy, stem cells and RNA interference — it will undoubtedly encounter setbacks before it can be used to help patients. © 2014 The New York Times Company

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19317 - Posted: 03.04.2014

Brendan Borrell Scientists can now take snapshots of where and how thousands of genes are expressed in intact tissue samples, ranging from a slice of a human brain to the embryo of a fly. The technique, reported today in Science1, can turn a microscope slide into a tool for creating data-rich, three-dimensional maps of how cells interact with one another — a key to understanding the origins of diseases such as cancer. The methodology also has broader applications, enabling researchers to create, for instance, unique molecular ‘barcodes’ to trace connections between cells in the brain, a stated goal of the US National Institutes of Health's Human Connectome Project. Previously, molecular biologists had a limited spatial view of gene expression, the process by which a stretch of double-stranded DNA is turned into single-stranded RNAs, which can in turn be translated into protein products. Researchers could either grind up a hunk of tissue and catalogue all the RNAs they found there, or use fluorescent markers to track the expression of up to 30 RNAs inside each cell of a tissue sample. The latest technique maps up to thousands of RNAs. Mapping the matrix In a proof-of-principle study, molecular biologist George Church of Harvard Medical School in Boston, Massachusetts, and his colleagues scratched a layer of cultured connective-tissue cells and sequenced the RNA of cells that migrated to the wound during the healing process. Out of 6,880 genes sequenced, the researchers identified 12 that showed changes in gene expression, including eight that were known to be involved in cell migration but had not been studied in wound healing, the researchers say. “This verifies that the technique could be used to do rapidly what has taken scientists years of looking at gene products one by one,” says Robert Singer, a molecular cell biologist at Albert Einstein College of Medicine in New York, who was not involved in the study. © 2014 Nature Publishing Group,

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 19306 - Posted: 03.01.2014

by Bethany Brookshire When most people think of the quintessential lab mouse, they think of a little white mouse with red eyes. Soft fur. A timid nature. But scientists think of something very different. This mouse is black, small and fast, with pink ears and a pinkish tail. It’s got black eyes to match. The fur may be soft, but the temper sure isn’t. This is the C57 Black 6 mouse. Each Black 6 mouse should be almost identical to every other Black 6 mouse. They have been bred to their own siblings for hundreds of generations, so there should be very few genetic differences left. But even supposedly identical mouse strains have their differences. These take the form of mutations in single DNA base pairs that accumulate in different populations. Recently, researchers showed that one of these tiny changes in a single gene was enough to produce a huge difference in how two groups of Black 6 mice respond to drugs. And the authors identified a surprising number of other small DNA differences still waiting to be explored. On one level, the new work offers scientists a novel tool for identifying genes that could relate to behaviors. But it also serves as a warning. “Identical” mouse populations aren’t as alike as many scientists had assumed. The Black 6, the most common lab mouse in the United States, is used for everything from drug abuse studies to cancer research. The Black 6 is also the reference strain for the Mouse Genome Sequencing Consortium. Whenever scientists discover a new genetic change in a mouse strain, they compare it first against the Black 6. And it’s the mouse used by the International Knockout Mouse Consortium (now the International Mouse Phenotyping Consortium), which keep a library of mouse embryos with different deleted genes. The Allen Brain Atlas, a database of neuroanatomy and gene activity throughout the mouse brain, relies on the Black 6 as well. © Society for Science & the Public 2000 - 2014

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 19097 - Posted: 01.04.2014

by Tina Hesman Saey BOSTON— Siberians may use genes to stay warm, a new study shows. As part of an effort to catalog genetic diversity in Siberia, Alexia Cardona of the University of Cambridge and collaborators sampled DNA from 200 Siberians representing 10 native groups. The team looked for genes that have more changes in Siberians than would be expected by chance — a sign that the genes evolved rapidly in the 24,000 years since people settled the frigid land. Rapid changes suggest that a gene is important for adapting to an environment. Several of the Siberians’ genes have variants that may help keep Arctic dwellers warm during the long winters, Cardona reported October 24 at the annual meeting of the American Society of Human Genetics. Among the candidates for genetic heaters are genes involved in metabolizing fats. Some Siberian groups eat mostly meat, so genes that help convert animal fat to energy are important for creating heat. Another gene with variants unique to Siberians is called PRKG1; it helps regulate body heat by controlling muscle contraction and the constriction and dilation of blood vessels. Muscle contractions are an important part of shivering, which can raise body temperature. The researchers also identified variants in genes involved in thyroid function, which plays a role in temperature regulation. A. Cardona et al. Genome-wide analysis of cold adaption in indigenous Siberian populations. American Society of Human Genetics annual meeting, Boston, October 24, 2013. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 18853 - Posted: 10.30.2013

By David Dobbs If you want a look at a high-profile field dealing with a lot of humbling snags, peer into #ASHG2013, the Twitter hashtag for last week’s meeting of the American Society of Human Genetics, held in Boston. You will see successes, to be sure: Geneticists are sequencing and analyzing genomes ever faster and more precisely. In the last year alone, the field has quintupled the rate at which it identifies genes for rare diseases. These advances are leading to treatments and cures for obscure illnesses that doctors could do nothing about only a few years ago, as well as genetic tests that allow prospective parents to bear healthy children instead of suffering miscarriage after miscarriage. But many of the tweets—or any frank geneticist—will also tell you stories of struggle and confusion: The current list of cancer-risk genes, the detection of which leads some people to have “real organs removed,” likely contains many false positives, even as standard diagnostic sequencing techniques are missing many disease-causing mutations. There’s a real possibility that the “majority of cancer predisposition genes in databases are wrong.” And a sharp team of geneticists just last week cleanly dismantled a hyped study from last year that claimed to find a genetic signature of autism clear enough to diagnose the risk of it in unborn children. This sample reads like an abstract of the entire field of genetics. In researching a book about genetics over the past four years, I’ve found a field that stands in a bizarre but lovely state of confusion—taken aback, but eager to advance; balanced tenuously between wild ambition and a deep but troubling humility. In the 13 years since the sequencing of the first human genome, the field has solved puzzles that 14 years ago seemed hopeless. Yet geneticists with any historical memory hold a painful awareness that their field has fallen short of the glory that seemed close at hand when Francis Collins, Craig Venter, and Bill Clinton announced their apparent triumph in June 2000. © 2013 The Slate Group, LLC

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 18846 - Posted: 10.29.2013

Intelligence tests were first devised in the early twentieth century as a way to identify children who needed extra help in school. It was only later that the growing eugenics movement began to promote use of the tests to weed out the less intelligent and eliminate them from society, sparking a debate over the appropriateness of the study of intelligence that carries on to this day. But it was not the research that was problematic: it was the intended use of the results. As the News Feature on page 26 details, this history is never far from the minds of scientists who work in the most fraught areas of behavioural genetics. Although the ability to investigate the genetic factors that underlie the heritability of traits such as intelligence, violent behaviour, race and sexual orientation is new, arguments and attitudes about the significance of these traits are not. Scientists have a responsibility to do what they can to prevent abuses of their work, including the way it is communicated. Here are some pointers. First: be patient. Do not speculate about the possibility of finding certain results, or about the implications of those results, before your data have even been analysed. The BGI Cognitive Genomics group in Shenzhen, China, is studying thousands of people to find genes that underlie intelligence, but group members sparked a furore by predicting that studies such as theirs could one day let parents select embryos with genetic predispositions to high intelligence. Many other geneticists are sceptical that the project will even find genes linked to this trait. © 2013 Nature Publishing Group

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 1: An Introduction to Brain and Behavior
Link ID: 18739 - Posted: 10.03.2013

By Fritz Andersen, It was hot that Sunday morning in February 2011 in Old San Juan. I had just retired after 40 years of cardiology practice in the suburbs of Washington, and my wife and I were spending the winter in Puerto Rico. A couple of friends had arrived by cruise ship, and I took them to see the 450-year-old Spanish fortress that sits above the entrance of the harbor. The fortress walls radiated heat, and after reentering the city we walked to our home for a breather and a refreshing ceiling fan. While sitting in the kitchen and sipping a beer, I suddenly passed out. I woke up a bit dizzy and confused; my friend, an internist from Arlington, told me I had had a grand mal seizure. My wife, Carmen Alicia, called a local friend, also a cardiologist, who sent us to a nearby hospital; there, an MRI exam revealed a small spot on my brain. The neurologist felt it needed to be biopsied to obtain a tissue diagnosis. I immediately returned to Virginia and went to several specialists, who suggested further testing before I decided to have an invasive brain biopsy. I also had a blood test for cysticercosis, an infection that results from eating undercooked pork contaminated with Tenia solium. This common parasite produces cysts all over the body, including the brain. It is the most common reason for seizures in many countries, particularly in India, where children with seizures are first treated for this disease even before other studies are done. My blood test was strongly positive. I started a course of oral medicine to treat it. The test reassured me. Unfortunately, my spot grew a bit over the course of three months, reaching the size of a grape. A biopsy and excision were now indicated. © 1996-2013 The Washington Post

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 18692 - Posted: 09.24.2013

By CARL ZIMMER From biology class to “C.S.I.,” we are told again and again that our genome is at the heart of our identity. Read the sequences in the chromosomes of a single cell, and learn everything about a person’s genetic information — or, as 23andme, a prominent genetic testing company, says on its Web site, “The more you know about your DNA, the more you know about yourself.” But scientists are discovering that — to a surprising degree — we contain genetic multitudes. Not long ago, researchers had thought it was rare for the cells in a single healthy person to differ genetically in a significant way. But scientists are finding that it’s quite common for an individual to have multiple genomes. Some people, for example, have groups of cells with mutations that are not found in the rest of the body. Some have genomes that came from other people. “There have been whispers in the matrix about this for years, even decades, but only in a very hypothetical sense,” said Alexander Urban, a geneticist at Stanford University. Even three years ago, suggesting that there was widespread genetic variation in a single body would have been met with skepticism, he said. “You would have just run against the wall.” But a series of recent papers by Dr. Urban and others has demonstrated that those whispers were not just hypothetical. The variation in the genomes found in a single person is too large to be ignored. “We now know it’s there,” Dr. Urban said. “Now we’re mapping this new continent.” Dr. James R. Lupski, a leading expert on the human genome at Baylor College of Medicine, wrote in a recent review in the journal Science that the existence of multiple genomes in an individual could have a tremendous impact on the practice of medicine. “It’s changed the way I think,” he said in an interview. Scientists are finding links from multiple genomes to certain rare diseases, and now they’re beginning to investigate genetic variations to shed light on more common disorders. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18657 - Posted: 09.17.2013

By Shinnosuke Nakayama and The Conversation In our society, not many people are lucky enough to have an ideal boss who they would want to follow faithfully for the rest of their lives. Many might even find their boss selfish and arrogant or complain that they don’t listen to their opinions. We humans push the concept of leaders and followers to the extreme but they exist throughout the animal kingdom. These leaders and followers of the natural world could help us decide whether that unpopular boss can learn to be part of the team. Leaders and followers are found in many group-living animals, such as fish, birds and primates. Group living can offer many benefits to group members, such as increasing the chances of finding food or avoiding predators. Unlike some human workplaces, groups of animals know that they need to agree on where to go and when to go there in order to take full advantage of group living. Leaders share common characteristics, so are to some extent predictable. In humans, leaders generally show higher scores in certain personality traits, notably extraversion. Similarly, in animals, bolder and more active individuals tend to be found as leaders. Evolutionary theories suggest that boldness and leadership can coevolve through positive feedback. Individuals who force their preferences on others are more likely to be followed, which in turn encourages these individuals to initiate more often. This feedback results in distinct social roles for leaders and followers within a group, as shown by several experimental studies. It would therefore seem that leaders and followers are born through natural selection, and that you have no chance of becoming a leader if you are born a follower. But our work with stickleback fish suggests that while followers may not have what it takes to lead, leaders can learn to follow. © 2013 Scientific American

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 11: Emotions, Aggression, and Stress
Link ID: 18580 - Posted: 08.29.2013

By Tina Hesman Saey Genetic factors may exert a tiny influence on how much schooling a person ends up with, a new study suggests. But the main lesson of the research, experts say, should be that attributing cultural and socioeconomic traits to genes is a dicey enterprise. “If there is a policy implication, it’s that there’s even more reason to be skeptical of genetic determinism,” says sociologist Jeremy Freese of Northwestern University in Evanston, Ill. Published May 30 in Science by a group of more than 200 researchers, the study does mark the first time genetic factors have been reproducibly associated with a social trait, says Richard Ebstein, a behavioral geneticist at the National University of Singapore. “It announces to social scientists that some things they’ve been studying that make a difference to health and life success do have a base in genetics.” But even if it does survive further inspection — and many similar links between genes and social characteristics have not — the study accounts for no more than 2 percent of whatever it is that makes one person continue school while someone in similar circumstances chooses to move on to something else. Previous studies comparing twins and family members have suggested that not-yet-identified genetic factors can explain 40 percent of people’s educational attainment; factors such as social groups, economic status and access to education would explain the other 60 percent. That percentage attributed to genetics is similar to the heritability of physical and medical characteristics such as weight and risk of heart disease.That makes a hunt for the genetic factors underlying educational attainment an attractive prospect. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 14: Attention and Consciousness
Link ID: 18211 - Posted: 06.01.2013

By Tina Hesman Saey COLD SPRING HARBOR, N.Y. – Taming foxes changes not only the animals’ behavior but also their brain chemistry, a new study shows. The finding could shed light on how the foxes’ genetic cousins, wolves, morphed into man’s best friend. Lenore Pipes of Cornell University presented the results May 10 at the Biology of Genomes conference. The foxes she worked with come from a long line started in 1959 when a Russian scientist named Dmitry Belyaev attempted to recreate dog domestication, but using foxes instead of wolves. He bred silver foxes (Vulpes vulpes), which are actually a type of red fox with white-tipped black fur. Belyaev and his colleagues selected the least aggressive animals they could find at local fox farms and bred them. Each generation, the scientists picked the tamest animals to mate, creating ever friendlier foxes. Now, more than 50 years later, the foxes act like dogs, wagging their tails, jumping with excitement and leaping into the arms of caregivers for caresses. At the same time, the scientists also bred the most aggressive foxes on the farms. The descendents of those foxes crouch, flatten their ears, growl, bare their teeth and lunge at people who approach their cages. The foxes’ tame and aggressive behaviors are rooted in genetics, but scientists have not found DNA changes that account for the differences. Rather than search for changes in genes themselves, Pipes and her colleagues took an indirect approach, looking for differences in the activity of genes in the foxes’ brains. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18164 - Posted: 05.16.2013

Ed Yong The US adolescents who signed up for the Study of Mathematically Precocious Youth (SMPY) in the 1970s were the smartest of the smart, with mathematical and verbal-reasoning skills within the top 1% of the population. Now, researchers at BGI (formerly the Beijing Genomics Institute) in Shenzhen, China, the largest gene-sequencing facility in the world, are searching for the quirks of DNA that may contribute to such gifts. Plunging into an area that is littered with failures and riven with controversy, the researchers are scouring the genomes of 1,600 of these high-fliers in an ambitious project to find the first common genetic variants associated with human intelligence. The project, which was launched in August 2012 and is slated to begin data analysis in the next few months, has spawned wild accusations of eugenics plots, as well as more measured objections by social scientists who view such research as a distraction from pressing societal issues. Some geneticists, however, take issue with the study for a different reason. They say that it is highly unlikely to find anything of interest — because the sample size is too small and intelligence is too complex. Earlier large studies with the same goal have failed. But scientists from BGI’s Cognitive Genomics group hope that their super-smart sample will give them an edge, because it should be enriched with bits of DNA that confer effects on intelligence. “An exceptional person gets you an order of magnitude more statistical power than if you took random people from the population — I’d say we have a fighting chance,” says Stephen Hsu, a theoretical physicist from Michigan State University in East Lansing, who acts as a scientific adviser to BGI and is one of the project’s leaders. © 2013 Nature Publishing Group,

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 1: An Introduction to Brain and Behavior
Link ID: 18159 - Posted: 05.15.2013

Stephen S. Hall Male sexual dysfunction is never pretty, even in nematodes. In normal roundworm courtship, a slender male will sidle up to a plump hermaphrodite, make contact, and then initiate a set of steps leading up to insemination: a sinuous backwards motion as he searches for the sexual cleft, a pause to probe, and finally the transfer of sperm. The whole business is usually over in a couple of minutes. “It's very slithery, and affectionate,” says Cornelia Bargmann, who has been observing the behaviour of this particular worm, Caenorhabditis elegans, for 25 years. Last October, scientists in Bargmann's laboratory at the Rockefeller University, New York, reported the discovery of a gene that seems to be crucial to successful mating. Disrupting the action of this gene causes male sexual confusion of almost epic pathos: nematodes with certain mutations poke tentatively at an inert hermaphrodite, making confused, fruitless curlicues around the potential mate. Occasionally the mutant male succeeds, but often he literally falls off the job and begins the search anew for a mate. Jennifer Garrison, a postdoc of Bargmann's who tracked the behaviour of these males, just shakes her head as she replays the scene on her computer screen. “Really sad,” she says. There are two punchlines to this story of thwarted invertebrate mating. One is the charming squeamishness with which Bargmann describes it, hesitating at words such as “vulva” and “spicule” and other anatomical gewgaws of roundworm reproduction. “As a well-brought-up Southern girl,” she says with a laugh, “it's still difficult to talk about this!” © 2013 Nature Publishing Group

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17828 - Posted: 02.20.2013

IF TWO animals have identical brain cells, how different can they really be? Extremely. Two worm species have exactly the same set of neurons, but extensive rewiring allows them to lead completely different lives. Ralf Sommer of the Max Planck Institute for Developmental Biology in Tübingen, Germany, and colleagues compared Caenorhabditis elegans, which eats bacteria, with Pristionchus pacificus, which hunts other worms. Both have a cluster of 20 neurons to control their foregut. Sommer found that the clusters were identical. "These species are separated by 200 to 300 million years, but have the same cells," he says. P. pacificus, however, has denser connections than C. elegans, with neural signals passing through many more cells before reaching the muscles (Cell, doi.org/kbh). This suggests that P. pacificus is performing more complex motor functions, says Detlev Arendt of the European Molecular Biology Laboratory in Heidelberg, Germany. Arendt thinks predators were the first animals to evolve complex brains, to find and catch moving prey. He suggests their brains had flexible wiring, enabling them to swap from plant-eating to hunting. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17749 - Posted: 02.04.2013

by Michael Balter CAMBRIDGE, UNITED KINGDOM—Siberia may not be everyone's idea of a tourist destination, but it has been home to humans for tens of thousands of years. Now a new study of indigenous Siberian peoples presented here earlier this month at a meeting on human evolution reveals how natural selection helped people adapt to the frigid north. The findings also show that different living populations adapted in somewhat different ways. Siberia occupies nearly 10% of Earth's land mass, but today it's home to only about 0.5% of the world's population. This is perhaps not surprising, since January temperatures average as low as -25°C. Geneticists have sampled only a few of the region's nearly one dozen indigenous groups; some, such as the 2000-member Teleuts, descendants of a once powerful group of horse and cattle breeders also known for their skill in making leather goods, are in danger of disappearing. Previous research on cold adaptation included two Siberian populations and implicated a couple of related genes. For example, genes called UCP1 and UCP3 tend to be found in more active forms in populations that live in colder climes, according to work published in 2010 by University of Chicago geneticist Anna Di Rienzo and her colleagues. These genes help the body's fat stores directly produce heat rather than producing chemical energy for muscle movements or brain functions, a process called "nonshivering thermogenesis." The new study sampled Siberians much more intensely, including 10 groups that represent nearly all of the region's native populations. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 17730 - Posted: 01.29.2013

Ewen Callaway Even as home experiments go, Hopi Hoekstra’s one was peculiar: she built a giant plywood box in her garage in San Diego, California, filled it with more than a tonne of soil and then let a pet mouse dig away. “This thing was bursting at its seams and held together with duct tape,” says the evolutionary biologist, now at Harvard University in Cambridge, Massachusetts. “But it worked.” It allowed her to study the genetics of burrowing behaviour in a controlled setting. Armed with plastic casts of the burrows and state-of-the-art sequencing, Hoekstra’s team discovered clusters of genes that partly explain why the oldfield mouse (Peromyscus polionotus) builds elaborate two-tunnel burrows, whereas its close relative, the deer mouse (Peromyscus maniculatus), goes for a simple hole in the ground1. The findings highlight an underappreciated benefit of a genomics revolution that is moving at breakneck speed. Thanks to cheap and quick DNA sequencing, scientists interested in the genetics of behaviour need not limit themselves to a handful of favourite lab organisms. Instead, they can probe the genetic underpinnings of behaviours observed in the wild, and glean insights into how they evolved. “In my mind, the link between genes and behaviour in natural populations and organisms is the next great frontier in biology,” says Hoekstra. Oldfield mice are native to the southeastern United States, where they burrow in soils ranging from sandy beaches to silt-rich clays. Wherever they dig, their holes look much the same, with a long entrance tunnel and a second tunnel that stops short of the surface and allows them to escape predators. Such invariability hints that the trait is encoded in DNA, says Hoekstra. © 2013 Nature Publishing Group

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17693 - Posted: 01.17.2013

by Elizabeth Norton To humans, all fire ants may look alike. But the tiny, red, stinging bugs known as Solenopsis invicta have two types of social organization, and these factions are as recognizable to the ants as rival football teams are to us. Researchers once thought that the groups' distinct physiological and behavioral profiles stemmed from a variant in a single gene. Now, a new study provides the first evidence that the gene in question is bound up in a bundle of some 600 other genes, versions of which are all inherited together. This "supergene" takes up a large chunk of what may be the first known social chromosome, analogous to the chromosomes that determine sex in humans. The differences between the two types of fire ants start with the winged queens, according to evolutionary geneticist Laurent Keller of the University of Lausanne in Switzerland. A so-called monogyne queen is large, fat, and fertile. Once she's mated, she can fly long distances to start her colony, nourishing her eggs from her fat stores, and then wait until her larvae grow up into workers. A monogyne colony will accept only the original queen and kill any other that shows up; these ants are very aggressive in general. By contrast, a polygyne queen is smaller and needs mature workers to help set up a colony. Thus polygyne communities will accept multiple queens from nearby nests—unless, that is, one happens to be a monogyne, in which case, they kill her. In 1998, working with entomologist and geneticist Kenneth Ross of the University of Georgia in Athens, Keller showed that the two groups of fire ants had distinct versions of a gene known as Gp-9. All of the monogynes had two copies of one form; among the polygynes, many had one normal and one mutated copy of the gene. At first glance, the finding made sense. © 2010 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 17691 - Posted: 01.17.2013

By Razib Khan In Slate there is an important piece up, The Early Education Racket, which attempts to reassure upper middle striving types that it isn’t the end of the world if their children don’t get into the right preschool. It is important because there are many people out there with lots of money (or perhaps more accurately, just enough money) and no common sense. Though the author, Melinda Wenner Moyer, offers that she’s not “making a Bell Curve argument here,” the general thesis that there are diminishing returns to inputs on childhood environment is well known to anyone with a familiarity with behavior genetics. Here’s a piece in Psychology Today from 1993, So Long, Superparents: If you are doubtful of this, I recommend you read The Nurture Assumption. This book was published in 1999, and Steve Pinker reported on the results in The Blank Slate a few years later, where I first encountered the thesis. The basic insight, that parental home environment seems to have minimal predictive power in explaining variation in outcomes, is still not very well known. The two primary issues to keep in mind are: 1) A substantial proportion of the variation in I.Q. and personality is heritable in a genetic sense. Many observations of parent-child similarities presumed that they were due to learning and emulation, but statistical analysis suggests this is not the case. Today, with genomic understanding of sibling relatedness (recall that though siblings should be related 0.50, there is some variation about this value) this seems more true than ever; much of the difference between siblings seems to be due to the variation of their genetic make up.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17688 - Posted: 01.17.2013

By Gary Stix The Atlantic featured a captivating fantasy in its November issue about a scenario to assassinate the U.S. president in 2016 by using a bioweapon specifically tailored to his genetic makeup—a virus that targeted the commander in chief and no one else. A great plot for a Hollywood thriller. But will we really see four years from now an engineered pathogen that could home in on just one person’s DNA, a lethal microbe that could be transmitted from person to person by a sneeze? The authors, including “genomic futurist” Andrew Hessel and cybercrime expert Marc Goodman, both faculty at Ray Kurzweil’s Singularity University, acknowledge that the plausibility of a hit on the president by the time of the next election might be reaching a bit. A personal gene bomb monogrammed for Barack Obama is still beyond the technical acumen of the best genetic engineers. But there is one good use beyond the cloaks and daggers to which the president’s genes might eventually be put. As Obama begins his second term next week, he has begun to contemplate his historical legacy. For his third act—that is, once he leaves office—he might consider extending that legacy further by undertaking a whole genome scan. Obama’s genome, as much as that of anyone alive, might help a bit in the long-running search for genes associated with emotional and psychological resilience. Anyone who runs for president and gets the nomination has to display a measure of mental toughness, and so might carry a set of such genes. Romney was a toughie too—recall the first debate—but he was also to the manner born, doing what was expected for someone of his breeding. © 2013 Scientific American

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 11: Emotions, Aggression, and Stress
Link ID: 17684 - Posted: 01.15.2013

By Susan Lunn, CBC News It's the time of year when people take stock of the past 12 months, and make resolutions for the New Year. That's kind of what Svante Paabo is doing — but the Swedish archeological geneticist is looking over a time span of 30,000 years. He's almost finished mapping the DNA of neanderthal man, a distant cousin of modern humans. Paabo has found that many people today carry within their DNA about 3 to 5 per cent in common with neanderthals. Paabo says it's important to learn more about our caveman cousins' DNA to reveal the differences between us and them, differences that have seen modern humans surive and thrive over the millennia, while neanderthals have become extinct. "I really hope that over the next 10 years we will understand much more of those things that set us apart. Which changes in our genome made human culture and technology possible? And allowed us to expand and become 7, 8, 9 billion people and spread all over the world?," he asked at a recent genetic conference in Ottawa. The room was packed with people from across North America who wanted to hear Paabo speak. He's recognized as the inspiration for Michael Crichton's Jurassic Park. © CBC 2012

Related chapters from BP7e: Chapter 6: Evolution of the Brain and Behavior; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17642 - Posted: 12.29.2012