Lifeboat Foundation: Safeguarding Humanity
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Category: genetics – Page 432

“There was something else, too – something weirder. Of all the non-human DNA fragments the team gathered, 99 percent of them failed to match anything in existing genetic databases the researchers examined. We found a whole new class of human-infecting ones that are closer to the animal class than to the previously known human ones, so quite divergent on the evolutionary scale.”

A landmark Stanford 2017 study indicates that more than 99 percent of the microbes inside us are unknown to science. The survey of DNA fragments circulating in the blood suggests the microbes living within us are vastly more diverse than previously known. In fact, 99 percent of that DNA has never been seen before.

A new survey of DNA fragments circulating in human blood suggests our bodies contain vastly more diverse microbes than anyone previously understood. What’s more, the overwhelming majority of those microbes have never been seen before, let alone classified and named, Stanford researchers reported in the Proceedings of the National Academy of Sciences.

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Almost half of our DNA sequences are made up of jumping genes—also known as transposons. They jump around the genome in developing sperm and egg cells and are important to evolution. But their mobilization can also cause new mutations that lead to diseases, such as hemophilia and cancer. Remarkably little is known about when and where their movements occur in developing reproductive cells, the key process that ensures their propagation in future generations, but can lead to genetic disorders for the hosts.

To address this problem, a team of Carnegie researchers developed new techniques to track the mobilization of jumping genes. They found that during a particular period of , a group of jumping-genes called retrotransposons hijacks special called nurse cells that nurture the developing eggs. These jumping genes use nurse cells to produce invasive material (copies of themselves called ) that move into a nearby egg and then mobilize into the egg’s DNA. The research is published in the July 26 on-line issue of Cell.

Animals have unwittingly developed a powerful system to suppress jumping gene activity that uses small, non-coding RNAs called piRNAs, which recognize jumping genes and suppress their activity. Occasionally, jumping genes still manage to move, suggesting that they employ some special tactics to escape piRNA control. However, tracking the mobilization of jumping genes to understand their tactics has been a daunting task.

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An ambitious effort to sequence the genome of every complex organism on Earth was officially launched on 1 November in London.

“Variation is the fount of all genetic knowledge,” says project member and evolutionary geneticist Jenny Graves of La Trobe University in Melbourne, Australia. “The more variation you have the better — so why not sequence everything?”

The Earth BioGenome Project aims to sequence the genomes of the roughly 1.5 million known animal, plant, protozoan and fungal species — collectively known as eukaryotes — worldwide over the next decade. The initiative is estimated to cost US$4.7 billion, although only a small proportion of that money has been committed so far.

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New research shows how police could use forensic DNA to track down a suspect’s relatives in genealogy databases that store a different kind of genetic data—and that were never intended for use in police investigations.

In other words, if your sibling leaves DNA at a crime scene, it could lead detectives to your door. That suggests new investigative possibilities for police—and also new concerns about genetic privacy and whether authorities who use forensic DNA in creative ways might be overstepping their bounds, says Noah Rosenberg, a professor of biology at Stanford University and senior author of a study, which appears in Cell.

“The potential to link people’s genotypes across databases has been developing for some time. It is both of interest and concerning, depending on one’s point of view,” says Rosenberg, who is also a member of Stanford Bio-X.

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Evidence has been building in recent years that our diet, our habits or traumatic experiences can have consequences for the health of our children — and even our grandchildren. The explanation that has gained most currency for how this occurs is so-called ‘epigenetic inheritance’ — patterns of chemical ‘marks’ on or around our DNA that are hypothesised to be passed down the generations. But new research from the University of Cambridge suggests that this mechanism of non-genetic inheritance is likely to be very rare.

A second study, also from Cambridge, suggests, however, that one way that environmental effects are passed on may in fact be through molecules produced from the DNA known as RNA that are found in a father’s sperm.

The mechanism by which we inherit innate characteristics from our parents is well understood: we inherit half of our genes from our mother and half from our father. However, the mechanism whereby a ‘memory’ of the parent’s environment and behaviour might be passed down through the generations is not understood.

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