The 20th annual Symposium will be held on Thursday, April 23, 2009.

Wolbachia Bacteria Overreplicate and Localize to the CNS in Wild Populations of Drosophila simulans and melanogaster
Poster Session-Science Complex Atrium, 4:00 PM

Bryan  Hornacek,   '09 78
   Major: Biology
   Hometown: Novi, MI

Sponsor(s): Roger Albertson
Support: FURSCA

Abstract: 
In millions of insects worldwide, Wolbachia bacteria manipulate host reproduction to increase their own reproductive success. One strategy utilized in Drosophila includes cytoplasmic incompatibility (CI) between uninfected females and infected males. Wolbachia can also alter host behavior: infected males mate at a higher rate than uninfected males. In many Drosophila species, Wolbachia induces strong CI and persists at a high titer in the germline and syncytial embryos. However, strains known to infect D. melanogaster (wMel and wPopcorn) show very weak CI and a low titer. To isolate Wolbachia variants, wild populations of D. simulans and D. melanogaster were collected in Big Sur California and southern Michigan. Immunohistochemisty of Big Sur populations revealed that infected D. simulans strains had robust Wolbachia localization to various tissue types, including nervous tissue, throughout embryo and larval development. Destabalizing drugs indicate that Wolbachia utilize host microtubules, rather than actin, to localize preferentially to neuroblast stem cells. Localization to mature neurons suggests Wolbachia may influence host mating behavior by altering brain cell function. Michigan collections revealed a Wolbachia variant that overreplicates in D. melanogaster somatic tissue during embryogenesis which persists at a higher titer than wMel or wPopcorn. High titer levels in this newly identified strain will allow subsequent functional studies that take advantage of the powerful molecular and genetic methods available to D. melanogaster.

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