A Chilled Story

SLC30A9 - A Cold Survivor

When Homo sapiens ventured from Africa into the colder lands of Eurasia, those ancient human encountered other species of ancient humans and began to mix their genes.

Naturally the sharing of DNA also exhibits in their mental and physical characters over the years but in a recently found study shows not only the Neanderthals but also a Denisovan group of people shares a rare gene with modern man which helps them to survive in extreme cold climate.

the Denisovan-originated human gene variant SLC30A9 has passed into a majority of modern populations, and could be to blame for knocking off modern mental equilibrium.

SLC30A9 helps control the transportation of zinc across cell membranes. The gene, coding for the ZnT9 protein, has some real benefits—especially in cold climates, as its role in cellular metabolism helped humans adapt to cold weather. But it has some cons as well. Namely, zinc imbalances may result in neurological abnormalities such as depression, hyperactivity disorder, autism spectrum disorder, and schizophrenia.

The researchers believe that this newfound link to the past may offer a window into understanding the Denisovan DNA that still exists in modern humans. While Neanderthal DNA has been found to impact everything from nose shape to disease susceptibility in a wide variety of people, Denisovan DNA has largely been seen in smaller groups. For example, in one Tibetan population, it has been seen to help humans adapt to life at high altitudes.

The zinc link goes much further. Even though the variant was established in Asia, it spread to European and Native American populations, and is now found in populations across the planet (although, it is found much less frequently in Africa). The research team first noticed that the mechanism behind zinc transport differed between modern human populations in Africa and Asia.

While the variant could potentially provide a metabolic advantage for coping with hostile, cold climates, the adverse impacts have also lived on well beyond those original ancient encounters.

 

( Courtesy : PLOS Genetics )