title: Detection of the Wolbachia protein WPIP0282 in mosquito spermathecae: implications for cytoplasmic incompatibility.
abstract: Cytoplasmic incompatibility (CI) is a conditional sterility induced by the bacterium Wolbachia pipientis that infects reproductive tissues in many arthropods. Although CI provides a potential tool to control insect vectors of arthropod-borne diseases, the molecular basis for CI induction is unknown. We hypothesized that a Wolbachia-encoded, CI-inducing factor would be enriched in sperm recovered from spermathecae of female mosquitoes. Using SDS-PAGE and mass spectrometry, we detected peptides from the 56 kDa hypothetical protein, encoded by wPip_0282, associated with sperm transferred to females by Wolbachia infected males. We also detected peptides from the same protein in Wolbachia infected ovaries. Homologs of wPip_0282 and the co-transcribed downstream gene, wPip_0283, occur as multiple divergent copies in genomes of CI-inducing strains of Wolbachia. The operon is located in a genomic context that includes mobile genetic elements. The absence of wPip_0282 and wPip_0283 homologs from genomes of Wolbachia in filarial nematodes, as well as other members of the Rickettsiales, suggests a role as a candidate CI effector.
authors.affiliation: Department of Entomology, University of Minnesota, St. Paul, MN 55108, USA. beckm098@umn.edu
authors.forename: John F
authors.initials: JF
authors.lastname: Beckmann
authors.forename: Ann M
authors.initials: AM
authors.lastname: Fallon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003465:Culex / Q000737:chemistry / Q000382:microbiology* / Q000502:physiology*; D003593:Cytoplasm / Q000382:microbiology*; D005260:Female; D007246:Infertility; D008297:Male; D008969:Molecular Sequence Data; D010053:Ovary / Q000382:microbiology; D016415:Sequence Alignment; D013094:Spermatozoa / Q000737:chemistry / Q000382:microbiology*; D020577:Wolbachia / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins
keywords: 0282; Culex pipiens; Cytoplasmic incompatibility; Mass spectrometry; Mosquito; Wolbachia