Wolbachia pipientis is a widespread parasite of arthropods that manipulates the reproductive biology of its hosts in order to foster its own transmission via the egg cytoplasm. In 4 July Nature, Diana Starr and Thomas Cline at the University of California, Berkeley, US, show that the interaction between Wolbachia and a specific host regulator protein can rescue Drosophila oogenesis defects (Nature 2002, 418:76-79).

Starr and Cline used mutant D. melanogaster females that were prevented from making eggs by protein-coding lesions in Sex-lethal (Sxl) — the master regulator of sex determination. They observed that infection of these mutants with Wolbachia restored Drosophila fertility. In addition, suppression of sterility by Wolbachia was specific for Sxl discriminated markedly among similar germline-specific Sxl alleles.

"The fact that the interacting gene in this case has been studied so extensively and belongs to a model experimental organism can be exploited...