Showing posts from February, 2017

The Wolbachia "holy grail"

The once-obscure alpha-proteobacterium Wolbachia pipientis, was catapulted into medical relevance by the discovery that it inhibits the replication of RNA viruses .  However, it was first discovered for its odd quirk of manipulating insect reproduction . That's right, Wolbachia were called "reproductive parasites" and for a long time, no fitness benefit was attributed to them.  These intracellular masters do things like kill male offspring, feminize male offspring, induce parthenogenesis, and the most common phenotype, sperm-egg incompatibility (also known by its more complicated name: cytoplasmic incompatibility or CI) (Figure 1).   Figure 1. Modified from Werren et al., 2008 .  Wolbachia cause four distinct reproductive phenotypes in a range of arthropod orders (top).  The mechanisms behind CI - meaning how does  Wolbachia  induce it -  have been a mystery for some time.   When you make a cross between infected males and uninfected  Nasonia  females, unviable em