Tardigrades, also known as "water bears", are strange water-dwelling, eight-legged, segmented micro-animals.
Extremophiles, they have been found in a range of locations including Antarctica, Tasmania, the deep sea and tropical rainforests.
On the 18th November 2015, The University of North Carolina reports -
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Originally Posted by University of North Carolina
Tardigrades, nearly microscopic animals that can survive the harshest of environments, including outer space, hold the record for the animal that has the most foreign DNA.
(Chapel Hill, N.C. – Nov 18, 2015) –Researchers from the University of North Carolina at Chapel Hill have sequenced the genome of the nearly indestructible tardigrade, the only animal known to survive the extreme environment of outer space, and found something they never expected: that they get a huge chunk of their genome – nearly one-sixth or 17.5 percent – from foreign DNA.
“We had no idea that an animal genome could be composed of so much foreign DNA,” said co-author Bob Goldstein, faculty in the biology department in UNC’s College of Arts and Sciences. “We knew many animals acquire foreign genes, but we had no idea that it happens to this degree.”
The work, publish today in the Proceeding of the National Academy of Sciences, not only raises the question of whether there is a connection between foreign DNA and the ability to survive extreme environments, but further stretches conventional views of how DNA is inherited.
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“We think of the tree of life, with genetic material passing vertically from mom and dad,” said Boothby. “But with horizontal gene transfer becoming more widely accepted and more well known, at least in certain organisms, it is beginning to change the way we think about evolution and inheritance of genetic material and the stability of genomes. So instead of thinking of the tree of life, we can think about the web of life and genetic material crossing from branch to branch. So it’s exciting. We are beginning to adjust our understanding of how evolution works.”
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Press release here -
http://uncnews.unc.edu/2015/11/23/a-...m-foreign-dna/
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Originally Posted by Sciencealert.com
Scientists have sequenced the entire genome of the tardigrade, AKA the water bear, for the first time. And it turns out that this weird little creature has the most foreign genes of any animal studied so far – or to put it another way, roughly one-sixth of the tardigrade's genome was stolen from other species. We have to admit, we're kinda not surprised.
A little background here for those who aren’t familiar with the strangeness that is the tardigrade – the microscopic water creature grows to just over 1 mm on average, and is the only animal that can survive in the harsh environment of space. It can also withstand temperatures from just above absolute zero to well above the boiling point of water, can cope with ridiculous amounts of pressure and radiation, and can live for more than 10 years without food or water. Basically, it's nearly impossible to kill, and now scientists have shown that its DNA is just as bizarre as it is.
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Article in Science Alert here -
http://www.sciencealert.com/the-tard...-of-any-animal
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Originally Posted by Rachel Feltman, Washington Post
Tardigrades are weird. The tiny animals — otherwise known as water bears — are famous for surviving in the vacuum of space, among other impossibly hostile environments. But they just got even weirder: According to research published Monday in the Proceedings of the National Academy of Sciences, tardigrades get a massive chunk of their DNA from other organisms.
[This tiny animal can survive basically anything, including the vacuum of space]
"Foreign" DNA is not a foreign concept to scientists. Through a process called horizontal gene transfer, any organism can theoretically swap genes with another. It happens among bacteria all the time, which is how antibiotic resistance spreads so quickly. But it's less common in more complex, multicellular organisms. Most animals end up with a genome that's over 99 percent homegrown.
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Washington Post article -
https://www.washingtonpost.com/news/...from-bacteria/
