Armadillidiidae, members of the phylum Arthropoda, are commonly called pillbugs because they can roll into a tight ball. Their sex chromosomes can go bad because of disuse, and they obtain DNA from bacteria to refresh it. That hodgepodge of genetic material can result in pillbugs becoming female.
At the International Congress of Entomology on September 29, Richard Cordaux of the University of Poitiers announced that genetic analysis traces the DNA that results in females to Wolbachia bacteria. These microbes impact many arthropods. They can be transmitted from mother to offspring and have an influence on sex ratios that results in more female offspring.
Poitier and his colleague Clément Gilbert have shown that Wolbachia can create lady pill bugs by donating DNA directly to the pill bug genes. The researchers suggest that the bacteria can insert feminizing genes into pill bug chromosomes. This is another intriguing example of gene transfer, an area of increasing research interest.