Posts Tagged ‘Genes’

Posted: December 4, 2012 by Wildcat in Uncategorized
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Several “brainy” genes that were duplicated in a tiny sea creature nearly 550 million years ago may have led to the massive expansion in intelligence in vertebrate species, two new studies have found. The studies, published today (Dec. 2) in the journal Nature Neuroscience, suggest this duplication of certain genes spurred an explosion in the number of chemicals that regulate brain function in vertebrates (animals with backbones), thereby leading to greater intelligence, the research suggests. “This genome event produced a kind of cognitive big bang; it produced a large set of interesting behavior,” said study co-author Seth Grant, a neuroscientist at the University of Cambridge in the United Kingdom. “It produced a molecular toolbox, which in the case of the brain, produced many, many more proteins that you find in the synapses, the junctions between nerve cells.” The study showed that changes, or mutations, in these genes lead to learning problems in both mice and humans, as well as psychological disorders in humans, said Jeffrey Boore, the CEO of Genome Project Solutions, who was not involved in the study. That supports the notion that these genes “have diversified throughout evolution from their ancient duplications to perform important, specific, diverse roles in mammal cognition in behavior.” (via Intelligence Genes Found | Vertebrate Evolution | LiveScience)

Posted: November 21, 2012 by Wildcat in Uncategorized
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The prevailing wisdom has been that every cell in the body contains identical DNA. However, a new study of stem cells derived from the skin has found that genetic variations are widespread in the body’s tissues, a finding with profound implications for genetic screening, according to Yale School of Medicine researchers. Published in the Nov. 18 issue of Nature, the study paves the way for assessing the extent of gene variation, and for better understanding human development and disease. “We found that humans are made up of a mosaic of cells with different genomes,” said lead author Dr. Flora Vaccarino, the Harris Professor of Child Psychiatry at the Yale Child Study Center. “We saw that 30 percent of skin cells harbor copy number variations (CNV), which are segments of DNA that are deleted or duplicated. Previously it was assumed that these variations only occurred in cases of disease, such as cancer. The mosaic that we’ve seen in the skin could also be found in the blood, in the brain, and in other parts of the human body.” (via YaleNews | Skin cells reveal DNA’s genetic mosaic)

Posted: November 16, 2012 by Wildcat in Uncategorized
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Up to 10 per cent of the active genes of an organism that has survived 80 million years without sex are foreign, a new study from the University of Cambridge and Imperial College London reveals. The asexual organism, the bdelloid rotifer, has acquired a tenth of its active genes from bacteria and other simple organisms like fungi and algae. The findings were reported Nov. 15 in the journal PLoS Genetics. Bdelloid rotifers are best known for going 80 million years without sex, as they have evolved to reproduce successfully without males. Many asexual creatures go extinct without the benefit of traditional genetic evolution. However, bdelloids have flourished by developing ingenious ways of overcoming the limitations of being asexual. Bdelloids have also developed the fascinating ability to withstand almost complete desiccation when the freshwater pools they typically live in dry up. They can survive in the dry state for many years only to revive with no ill effect once water becomes available again. “We were thrilled when we discovered that nearly 10 per cent of bdelloids’ active genes are foreign, adding to the weirdness of an already odd little creature,” said Professor Alan Tunnacliffe, lead author of the study from the University of Cambridge. “We don’t know how the gene transfer occurs, but it almost certainly involves ingesting DNA in organic debris, which their environments are full of. Bdelloids will eat anything smaller than their heads!” (via Tenth of quirky creature’s active genes are foreign: Believed to ‘ingest’ DNA from other simple organisms)

Posted: November 15, 2012 by Wildcat in Uncategorized
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An international team led by the University of Edinburgh has discovered a new gene called miR-941 that helps explain how humans evolved evolved from apes by playing a crucial role in human brain development, and may shed light on how we learned to use tools and language. The researchers say it is the first time that a new gene — carried only by humans and not by apes — has been shown to have a specific function within the human body. They compared the human genome to 11 other species of mammals, including chimpanzees, gorillas, mouse and rat, to find the differences between them. The results showed that the gene — miR-941 — is unique to humans. The researchers say it emerged between six and one million years ago, after humans had evolved from apes. The gene is highly active in two areas of the brain that control our decision making and language abilities. The study suggests it could have a role in the advanced brain functions that make us human. It is known that most differences between species occur as a result of changes to existing genes, or the duplication and deletion of genes. But scientists say this gene emerged fully functional out of non-coding genetic material, previously termed “junk DNA,” in a startlingly brief interval of evolutionary time. Until now, it has been remarkably difficult to see this process in action. Researcher Dr. Martin Taylor, who led the study at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, said the results were significant. “As a species, humans are wonderfully inventive — we are socially and technologically evolving all the time. But this research shows that we are innovating at a genetic level too. (via New brain gene gives us edge over apes | KurzweilAI)

Posted: October 25, 2012 by Wildcat in Uncategorized
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Why some people respond to treatments that have no active ingredients in them may be down to their genes, a study in the journal PLoS ONE suggests. The so-called “placebo effect” was examined in 104 patients with irritable bowel syndrome (IBS) in the US. Those with a particular version of the COMT gene saw an improvement in their health after placebo acupuncture. The scientists warn that while they hope their findings will be seen in other conditions, more work is needed. Edzard Ernst, a professor of complementary medicine at the University of Exeter, said: “This is a fascinating but very preliminary result. “It could solve the age-old question of why some individuals respond to placebo, while others do not. “And if so, it could impact importantly on clinical practice. “But we should be cautious – the study was small, we need independent replications, and we need to know whether the phenomenon applies just to IBS or to all diseases.” (via BBC News – Placebo effect may be ‘down to genes’)

Posted: October 16, 2012 by Wildcat in Uncategorized
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Scientists have made the largest gene circuit ever reported—a step toward programming engineered bacteria to clean, produce biofuel, or fight infection.

We tend to assume computers are made of silicon, but there is actually no necessary connection between the machine and the material. All that an engineer needs to do to make a computer is to find a way to build logic gates—the elementary building blocks of digital computers—in whatever material is handy.

So logic gates could theoretically be made of pipes of water, channels for billiard balls, or even mazes for soldier crabs.

By comparison Tae Seok Moon’s ambition, which is to build logic gates out of genes, seems eminently practical. As a postdoctoral fellow in the lab of Christopher Voigt, a synthetic biologist at the Massachusetts Institute of Technology, he recently made the largest gene (or genetic) circuit yet reported.

Moon, now an assistant professor of energy, environmental, and chemical engineering at Washington University in St. Louis, is the lead author of an article describing the project in Nature. Voigt is the senior author.

The tiny circuits constructed from these gene gates and others like them may one day be components of engineered cells that will monitor and respond to their environments.

The number of tasks they could undertake is limited only by evolution and human ingenuity. Janitor bacteria might clean up pollutants, chemical-engineer bacteria pump out biofuels, and miniature infection-control bacteria might bustle about killing pathogens.

Posted: October 14, 2012 by Wildcat in Uncategorized
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By force of habit we tend to assume computers are made of silicon, but there is actually no necessary connection between the machine and the material. All that an engineer needs to do to make a computer is to find a way to build logic gates—the elementary building blocks of digital computers—in whatever material is handy. So logic gates could theoretically be made of pipes of water, channels for billiard balls or even mazes for soldier crabs. By comparison Tae Seok Moon’s ambition, which is to build logic gates out of genes, seems eminently practical. As a postdoctoral fellow in the lab of Christopher Voigt, PhD, a synthetic biologist at the Massachusetts Institute of Technology, he recently made the largest gene (or genetic) circuit yet reported. Moon, PhD, now an assistant professor of energy, environmental and chemical engineering in the School of Engineering & Applied Science at Washington University in St. Louis is the lead author of an article describing the project in the Oct. 7 issue of Nature. Voigt is the senior author. The tiny circuits constructed from these gene gates and others like them may one day be components of engineered cells that will monitor and respond to their environments. The number of tasks they could undertake is limited only by evolution and human ingenuity. Janitor bacteria might clean up pollutants, chemical-engineer bacteria pump out biofuels and miniature infection-control bacteria might bustle about killing pathogens. (via A complex logic circuit made from bacterial genes)