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DNA Database Brings Scientists Closer to Pinpointing Genes for Disease

Untitled-1Scientists say they are closer to pinning down the genetic causes of inherited diseases ranging from muscular dystrophy to certain types of heart disease after analysing the DNA of more than 60,000 people. Researchers have discovered more than 3,000 genes in which certain mutations are likely to play a role in disease, as well as more than 160 genetic mutations that have previously been linked to inherited conditions – but are in fact harmless. The findings will help to pin down whether genetic mutations seen in a patient are likely to be behind their disease.

The research is the fruit of an international collaboration, dubbed Exac, which pulled together data from around the world to produce the largest ever catalogue of variations in protein-coding regions of DNA, boasting data from 60,706 individuals.

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Who’s the Daddy? Female Fish Have Novel Way of Finding Reliable Mates

fishFemale fish have a novel way of finding Mr Right when it comes to picking fathers for their offspring, scientists have revealed. Like most other species of fish, female ocellated wrasse release their eggs into the water for fertilization by males, making just who ends up as the daddy something of a lottery. But now researchers have revealed that females are able to influence which males will succeed in fertilizing their eggs. Writing in the journal Nature Communications, a team of researchers from the US say that the female ocellated wrasse is able to sort Mr Nice from Mr Nasty thanks to a substance, known as ovarian fluid, that coats the eggs she has released. While the researchers are still teasing apart just how the ovarian fluid affects the reproductive success of the males, the study suggests that the ovarian fluid could be affecting the velocity and motion of the sperm. In a number of experiments, the researchers took eggs from female fish and either removed the ovarian fluid, left it in place, or removed it and then re-introduced the fluid. Sperm from both types of male were then introduced to the eggs simultaneously, with the fertilized eggs later analyses to determine their paternity. Further experiments introduced the sperm from each type of male separately to explore whether the influence of the ovarian fluid differed between them.

The results revealed that rather than attracting more nesting males, or simply offering an advantage to their sperm, the ovarian fluid appears to remove the numbers advantage for sperm of the sneaker males.

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Finding the Brain’s Generosity Centre

Would you give money to this man?Scientists from Oxford University and UCL have identified part of our brain that helps us learn to be good to others. The discovery could help understanding of conditions like psychopathy where people’s behaviour is extremely antisocial. The researchers were led by Dr Patricia Lockwood, who explained: ‘Prosocial behaviours are social behaviours that benefit other people. They are a fundamental aspect of human interactions, essential for social bonding and cohesion, but very little is currently known about how and why people do things to help others.’ The scientists used a well-understood model of how people learn to maximise good outcomes for themselves and applied this model to understand how people learn to help others. While being scanned in a MRI machine, volunteers had to work out which symbols were more likely to give them, or someone else, a reward. ‘This the first time anyone has shown a particular brain process for learning prosocial behaviours – and a possible link from empathy to learning to help others. By understanding what the brain does when we do things for other people, and individual differences in this ability, we are better placed to understand what is going wrong in those whose psychological conditions are characterised by antisocial disregard for others.’

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The Biggest Issue in Women’s Sports Is About to Come to a Head

Expectations are soaring for 25-year-old South African runner Caster Semenya, who races next week in the 800 meters. She’s favored to clinch a gold medal. She might even shatter the longest-running world record for track and field. And if she does, it could affect much more than the pride of her competitors. A big win for Semenya would likely add fuel to an already-fiery debate about gender and sports, and whether women like her should be allowed to race at all. For decades, the International Association of Athletics Federations (IAAF), the world’s governing body for track and field, has sought to preserve the male-female division in its sport through variations of sex testing—gynecological exams, chromosome tests, or hormone tests to make sure female competitors aren’t actually men trying to pass as women, or intersex women with masculine traits that might give them an unfair boost. Since 2011, sex testing has focused on testosterone. Women like Semenya whose functional levels of the hormone are within “the male range,” or higher than 10 nanomoles per liter of blood, have been barred from international competitions like the Olympics. But not this year. For the first time in more than half a century, female Olympians will not be subject to any form of sex testing in Brazil, which means intersex track athletes will be allowed to compete with their natural testosterone levels.

Now, as scientists struggle to determine how testosterone affects performance, thousands of athletes are converging on Rio de Janeiro for what some have described as a total “free-for-all,” as far as gender boundaries go. If Semenya dominates, will it be fair? What does the science say?

 

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Where There’s Smoke And A Mutation There May Be An Evolutionary Edge For Humans

Smoke Lab-HubbardA genetic mutation may have helped modern humans adapt to smoke exposure from fires and perhaps sparked an evolutionary advantage over their archaic competitors, including Neandertals, according to a team of researchers. Modern humans are the only primates that carry this genetic mutation that potentially increased tolerance to toxic materials produced by fires for cooking, protection and heating, said Gary Perdew, the John T. and Paige S. Smith Professor in Agricultural Sciences, Penn State. At high concentrations, smoke-derived toxins can increase the risk of respiratory infections. For expectant mothers, exposure to these toxins can increase the chance of low birth weight and infant mortality. “If you’re breathing in smoke, you want to metabolize these hydrophobic compounds and get rid of them, however, you don’t want to metabolize them so rapidly that it overloads your system and causes overt cellular toxicity,” said Perdew.

The researchers used computational and molecular techniques to examine the difference in the genetics of polycyclic aromatic hydrocarbon tolerance between humans and Neandertals. They examined a genomic database of humans, Neandertals and a Denisovan, a hominin more closely related to Neandertals than humans. “We thought the differences in aryl hydrocarbon receptor ligand sensitivity would be about ten-fold, but when we looked at it closely, the differences turned out to be huge,” said Perdew. “Having this mutation made a dramatic difference. It was a hundred-fold to as much of a thousand-fold difference.”

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2016 | Patrick Allard, et al – Exposure to the BPA-Substitute Bisphenol S Causes Unique Alterations of Germline Function

ISG faculty, Patrick Allard, and two Human Biology & Society students, among others, have published a paper entitled “Exposure to the BPA-Substitute Bisphenol S Causes Unique Alterations of Germline Function,” with PLOS Genetics, 2016.

ABSTRACT:

Concerns about the safety of Bisphenol A, a chemical found in plastics, receipts, food packaging and more, have led to its replacement with substitutes now found in a multitude of consumer products. However, several popular BPA-free alternatives, such as Bisphenol S, share a high degree of structural similarity with BPA, suggesting that these substitutes may disrupt similar developmental and reproductive pathways. We compared the effects of BPA and BPS on germline and reproductive functions using the genetic model systemCaenorhabditis elegans. We found that, similarly to BPA, BPS caused severe reproductive defects including germline apoptosis and embryonic lethality. However, meiotic recombination, targeted gene expression, whole transcriptome and ontology analyses as well as ToxCast data mining all indicate that these effects are partly achieved via mechanisms distinct from BPAs. These findings therefore raise new concerns about the safety of BPA alternatives and the risk associated with human exposure to mixtures.

Songbirds’ Epic Migrations Connected To A Small Cluster Of Genes

thrush-with-tracker_770Scientists from the University of British Columbia have shown that there is a genetic basis to the migratory routes flown by songbirds, and have narrowed in on a relatively small cluster of genes that may govern the behaviour. “It’s amazing that the routes and timing of such complex behaviour could be genetically determined and associated with a very small portion of the genome,” said researcher Kira Delmore, lead author of the paper published today in Current Biology. “What’s even more amazing is that differences in this behaviour could be helping to maintain the huge diversity of songbirds we see in the natural world.”

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Orangutan Gives Clues To The Origins Of Human Speech

An orangutan called Rocky could provide the key to understanding how speech in humans evolved from the time of the ancestral great apes, according to a study led by Dr Adriano Lameira of Durham University and published in the journal Scientific Reports. Previously it was thought that great apes, our closest evolutionary relatives, could not learn to produce new sounds. As the human ability to speak is a learned behaviour it was therefore thought that this could not have originated from the great apes. It was also believed that control over the voice, or vocal fold action, which would give them the capacity to learn vowel-like sounds, was not an ability the great apes had. However, the research team found that Rocky, an orangutan living at Indianapolis Zoo in the USA, was able to copy the pitch and tone of sounds made by researchers to make vowel-like calls. The findings, which suggest that orangutans could have the ability to control their voices, shed new light on debates about whether or not spoken language stemmed from early human ancestors.

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