IRGM

Among the non-coding DNA that composes a large percentage of the genomes of humans and other eukaryotic organisms, pseudogenes are genes that were once active but were rendered defunct by mutations at some point in evolutionary history. But some pseudogenes may regain their functionality. A study published in PLoS Genetics last week revealed that a gene that codes for a member of the immunity-related GTPase protein family, IRGM, was subject to a frameshift mutation in an ancestor of primates 40 million years ago, due to insertion of a small fragment of DNA. The non-functional pseudogene…

The world of genetics is filled with stories that are as gripping as the plot of any thriller. Take the IRGM gene - its saga, played out over millions of years, has all the makings of a classic drama. Act One: setting the scene. By duplicating and diverging, this gene thrived in the cells of most mammals as a trinity of related versions that played vital roles in the immune system. Act Two: tragedy strikes. About 50 million years ago, in the ancestors of today's apes and monkeys, the entire IRGM cluster was practically deleted, leaving behind a sole survivor. Things took a turn for the worse…