What makes us human? The answer may be found in overlooked DNA

2 years ago 432

Our DNA is precise akin to that of the chimpanzee, which successful evolutionary presumption is our closest surviving relative. Stem compartment researchers astatine Lund University successful Sweden person present recovered a antecedently overlooked portion of our DNA, alleged non-coded DNA, that appears to lend to a quality which, contempt each our similarities, whitethorn explicate wherefore our brains enactment differently. The survey is published successful the diary Cell Stem Cell.

The chimpanzee is our closest surviving comparative successful evolutionary presumption and probe suggests our kinship derives from a communal ancestor. About 5 to six cardinal years ago, our evolutionary paths separated, starring to the chimpanzee of today, and Homo Sapiens, humankind successful the 21st century.

In a caller study, stem compartment researchers astatine Lund examined what it is successful our DNA that makes quality and chimpanzee brains antithetic -- and they person recovered answers.

"Instead of studying surviving humans and chimpanzees, we utilized stem cells grown successful a lab. The stem cells were reprogrammed from tegument cells by our partners successful Germany, the USA and Japan. Then we examined the stem cells that we had developed into encephalon cells," explains Johan Jakobsson, prof of neuroscience astatine Lund University, who led the study.

Using the stem cells, the researchers specifically grew encephalon cells from humans and chimpanzees and compared the 2 compartment types. The researchers past recovered that humans and chimpanzees usage a portion of their DNA successful antithetic ways, which appears to play a sizeable relation successful the improvement of our brains.

"The portion of our DNA identified arsenic antithetic was unexpected. It was a alleged structural variant of DNA that were antecedently called "junk DNA," a agelong repetitive DNA drawstring which has agelong been deemed to person nary function. Previously, researchers person looked for answers successful the portion of the DNA wherever the protein-producing genes are -- which lone makes up astir 2 per cent of our full DNA -- and examined the proteins themselves to find examples of differences."

The caller findings frankincense bespeak that the differences look to prevarication extracurricular the protein-coding genes successful what has been labelled arsenic "junk DNA," which was thought to person nary relation and which constitutes the bulk of our DNA.

"This suggests that the ground for the quality brain's improvement are familial mechanisms that are astir apt a batch much analyzable than antecedently thought, arsenic it was expected that the reply was successful those 2 per cent of the familial DNA. Our results bespeak that what has been important for the brain's improvement is alternatively possibly hidden successful the overlooked 98 per cent, which appears to beryllium important. This is simply a astonishing finding."

The stem compartment method utilized by the researchers successful Lund is revolutionary and has enabled this benignant of research. The method was recognised by the 2012 Nobel Prize successful Physiology oregon Medicine. It was the Japanese researcher Shinya Yamanaka who discovered that specialised cells tin beryllium reprogrammed and developed into each types of assemblage tissue. And successful the Lund researchers' case, into encephalon cells. Without this technique, it would not person been imaginable to survey the differences betwixt humans and chimpanzees utilizing ethically defensible methods.

Why did the researchers privation to analyse the quality betwixt humans and chimpanzees?

"I judge that the encephalon is the cardinal to knowing what it is that makes humans human. How did it travel astir that humans tin usage their encephalon successful specified a mode that they tin physique societies, amended their children and make precocious technology? It is fascinating!"

Johan Jakobsson believes that successful the aboriginal the caller findings whitethorn besides lend to genetically-based answers to questions astir psychiatric disorders, specified arsenic schizophrenia, a upset that appears to beryllium unsocial to humans.

"But determination is simply a agelong mode to spell earlier we scope that point, arsenic alternatively of carrying retired further probe connected the 2 per cent of coded DNA, we whitethorn present beryllium forced to delve deeper into each 100 per cent -- a considerably much analyzable task for research," helium concludes.

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Materials provided by Lund University. Note: Content whitethorn beryllium edited for benignant and length.

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