Mitochondrial DNA mutations abound

ODRA NOELMembers of the 1,000 Genomes Project this week (July 7) showed that the mitochondrial DNA (mtDNA) of healthy people harbors plenty of pathogenic mutations. Their work was published in PNAS.

Metabolic disease specialist Neal Sondheimer of the Children’s Hospital of Philadelphia said the study “offers the intriguing possibility that maybe everybody has a little bit of something wrong with their mitochondrial DNA and that might play a role in aging.”

Intelligence is heritable

WIKIMEDIA, THOMAS LERSCHA team led by investigators at Georgia State University’s Neuroscience Institute reported in Current Biology this week (July 10) evidence to suggest chimpanzees inherit general intelligence from their parents. “This is really major evidence that . . . those estimates of the heritability of human intelligence are probably dead on,” Alexander Weiss, a psychologist at the University of Edinburgh in the U.K. who was not involved in...

Separately, researchers at University College London and their colleagues published a genome-wide association study (GWAS) involving 2,794 human twin pairs, showing a correlation among genetics, reading, and mathematical abilities. Their analysis appeared in Nature Communications this week (July 8).

Sperm show signs of mother’s stress

WIKIMEDIA, SEWERYN OLKOWICZMice that are malnourished while pregnant can pass down epigenetic markers of such stress to their sons’ sperm, according to a study published in Science this week (July 10). Scientists from the U.K.’s University of Cambridge and their colleagues showed that the germ cells of male mice whose mothers were malnourished while pregnant showed more hypomethylated DNA than did male mice whose mothers received the proper nutrition.

“There is a lot of interest in the impact of maternal nutrition on offspring metabolic disease but few studies have specifically examined the impact of maternal under-nutrition on sperm methylation—or examined the consequences [in grandchildren],” Margaret Morris of the University of New South Wales in Sydney told The Scientist in an e-mail. “It is interesting that the methylation changes were not maintained in the [second generation’s] offspring.”

Diving into DNA ancestry

FLICKR, GLYN LOWEMore and more people are swabbing their cheeks and sending off saliva to DNA ancestry testing companies, in part because the firms have stepped up their advertising efforts. But whether consumers know exactly what they’re buying is an open question—one that the top three firms are struggling to resolve as they educate the public on genetic genealogy basics.

“We have a generally low genetic literacy rate in the U.S. and elsewhere. It really is a struggle for these companies to take on the burden of educating consumers—they’re not just trying to sell their products . . . they have to educate individuals to know, what does this [type of testing] say, what does it not say, and all of the various nuances sometimes get lost,” said Jennifer Wagner, a Pennsylvania-based lawyer.

Other news in life science:

Neuroscientists Threaten to Boycott Brain Project
More than 250 European researchers sign a letter criticizing the European Commission’s $1.6 billion effort to create a computer simulation of the human brain.

Smallpox Vials Found in FDA Storage
Employees packing up an old storage unit run by the US Food and Drug Administration uncovered 16 forgotten vials of smallpox.

Human Gene Set Shrinks Again
Proteomic data suggest the human genome may encode fewer than 20,000 genes.

Insecticides Harm Birds Indirectly
The effects of neonicotinoid use on insect populations appear to be rippling through the food chain, scientists show.

New Catalog of Human Gut Microbes
An updated analysis of the gut microbiome extends the list of known bacterial genes to 9.8 million.

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