lunes, 18 de junio de 2012

Virus “Fossils” Reveal Neanderthals’ Kin

An analysis of virus fossils suggests Denisovans, not humans, were Neanderthals' closest relatives.

Humans and Neanderthals are close cousins. So close, in fact, that some researchers argue the two hominids might actually be members of the same species. But a few years ago, anthropologists discovered a mysterious new type of hominid that shook up the family tree. Known only from a finger fragment, a molar tooth and the DNA derived from both, the Denisovans lived in Asia and were contemporaries of Neanderthals and modern humans. And they might have been Neanderthals’ closest relatives. A recent study of virus “fossils” provides new evidence of this relationship.

Hidden inside each, embedded in our DNA, are the genetic remnants of viral infections that afflicted our ancestors thousands, even millions of years ago. Most known virus fossils are retroviruses, the group that includes HIV. Consisting of a single strand of RNA, a retrovirus can’t reproduce on its own. After the retrovirus invades a host cell, an enzyme reads the RNA and builds a corresponding strand of DNA. The virus-derived DNA then implants itself into the host cell’s DNA. By modifying the host’s genetic blueprints, the virus tricks the host into making new copies of the retrovirus...
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Hominid Hunting
Reference:
Neandertal and Denisovan retroviruses
Lorenzo Agoni, Aaron Golden, Chandan Guha, Jack Lenz
Current Biology - 5 June 2012 (Vol. 22, Issue 11, pp. R437-R438)

1 comentario:

Maju dijo...

Borra ^^, por favor.

No son "virus" sino un provirus, es decir una cadena vírica insertada en el ADN humano pero inactiva (si estuviera activa sería un retrovirus). Por lo tanto pertenece al DNA autosómico humano (neandertal y denisovano).

También hay varios provirus denisovanos no encontrados en los neandertales, lo que me parece sugerente de apoyar la hipótesis de la hibridación.