Saturday, March 7, 2009

Gene Stories

As genomic analysis expands, incredible and strange stories of the history of genes are emerging. These are stories of tragedy and triumph, life and death. Science details the curious case of the IRGM gene, which was lost and then found again. IRGM, immunity-related GTPase family, M, is thought to play a role in immune function, specifically the process of autophagy in which programmed cell destruction allows, among other things, nutrient conservation and the removal of infected cells. The gene was lost about 50 million years ago in the ancestor that we share with monkeys. Then 25 million years ago, IRGM came back in the line that became great apes and us. Comparative genomics suggests that an ancient retrovirus and a couple of gene mutations conspired to rouse the sleeping gene. Geneticist Evan Eichler and his colleagues now have the question of how the new gene works. This is but one of innumerable quiet epics written in every cell of our bodies.

(image credit: Cemalettin Bekpen/, via