Artigo na New Scientist sobre genes ORFan

quinta-feira, janeiro 24, 2013

Artigo na New Scientist sobre genes ORFan

Uncommon Descent 

22 de janeiro de 2013

A revista New Scientist trás um artigo interessante sobre o assunto de genes ORFan (i.e. genes que não possuem nenhum homólogo conhecido):

NOT having any family is tough. Often unappreciated and uncomfortably different, orphans have to fight to fit in and battle against the odds to realise their potential. Those who succeed, from Aristotle to Steve Jobs, sometimes change the world.

Who would have thought that our DNA plays host to a similar cast of foundlings? When biologists began sequencing genomes, they discovered that up to a third of genes in each species seemed to have no parents or family of any kind. Nevertheless, some of these “orphan genes” are high achievers, and a few even seem have played a part in the evolution of the human brain.

But where do they come from? With no obvious ancestry, it was as if these genes had appeared from nowhere, but that couldn’t be true. Everyone assumed that as we learned more, we would discover what had happened to their families. But we haven’t …




A hipótese de ancestralidade comum - descendência com modificação, a cada dia que passa vai se enfraquecendo como explicação evolucionária. Vide esses dois artigos importantes:

1. Molecular Biology and Evolution

For about 23% of our genome, we share no immediate genetic ancestry with our closest living relative, the chimpanzee. This encompasses genes and exons to the same extent as intergenic regions. We conclude that about 1/3 of our genes started to evolve as human-specific lineages before the differentiation of human, chimps, and gorillas took place.”

(Ingo Ebersberger, Petra Galgoczy, Stefan Taudien, Simone Taenzer, Matthias Platzer, and Arndt von Haeseler, “Mapping Human Genetic Ancestry,” Molecular Biology and Evolution, Vol. 24(10):2266-2276 (2007).) FREE PDF GRATIS

2. Nature

An integrated encyclopedia of DNA elements in the human genome – Sept. 6, 2012

Excerpt: Analysis... yielded 57 confidently identified unique peptide sequences in intergenic regions relative to GENCODE annotation. Taken together with evidence of pervasive genome transcription, these data indicate that additional protein-coding genes remain to be found.