Submitted to: Insect Molecular Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/30/2006
Publication Date: 6/20/2006
Citation: Collins, A.M., Caperna, T.J., Williams, V.P., Garrett, W.M., Evans, J.D. 2006.Proteomic analyses of male contributions to honey bee sperm storage and mating. Insect Molecular Biology. 15(5):541-549. Interpretive Summary: The honey bee is an important agricultural insect by pollinating more than 90 crops and providing honey and other commercial products. This work reflects two longstanding goals of bee research: improving the egg-laying lifespan of queens and developing methods for preserving genetic lines that show disease resistance and other desirable traits. The latter goal is helpful for beekeepers in the short term and essential for the exploiting new data from the Honey Bee Genome Project in the long term. Here we search the bee genome for matches to proteins collected from male honey bees and from semen itself. We discuss dozens of such matches and show which ones are likely to be important in sperm survival and the effective fertilization of queens. The results will aid beekeepers seeking to extend sperm viability for artificial insemination, and researchers looking for ways to preserve honey bee sperm from lines showing promising traits.
Technical Abstract: Honey bee (Apis mellifera L.) queens, as in most other social Hymenoptera, mate early in life and then store sperm to be used throughout their lifetimes. There has been longstanding interest in the mechanisms that allow social insect sperm to survive this long. Results from our previous studies indicated that honey bee males contributed significantly to the physiology of sperm survival. Proteins were extracted from seminal vesicles and semen of mature drones, separated by 2D-PAGE gel electrophoresis, digested with trypsin, and analyzed by peptide mass fingerprinting (MALDI-TOF). Mascot searches against NCBI nr and honey-bee specific databases, plus local sequence BLASTP searches against Drosophila melanogaster were performed. We found significant GLEAN3 matches from 60 protein spots from seminal vesicles (54 unique proteins), plus one additional match to a novel peptide predicted by Genscan. We found 78 GLEAN3 matches to genes present in semen (33 unique). Of the 69 unique honey bee proteins found, 66 showed matches to proteins in the genome of Drosophila melanogaster. Two of the remaining proteins showed no non-bee matches in nr while a third seems to be a widespread protein lost from the fly genome. When organized into GO groups there is an apparent over-representation of genes implicated in the glycolysis pathway, although other carbohydrate metabolism and two antioxidant genes were also present. We found significant biases in metabolism-associated proteins in semen versus the seminal vesicle. Accessory gland proteins from Drosophila rarely found orthologs in the bee proteins identified here. Implications for queen physiology are discussed.