Submitted to: Insect Biochemistry and Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 2004
Publication Date: June 1, 2004
Citation: Collins, A.M., Evans, J.D., Williams, V.P. 2004. Antioxidant gene expression and sperm storage in the honey bee apis mellifera. Insect Biochemistry and Molecular Biology. 13:141-146.
Interpretive Summary: The ability to store honey bee semen for extended periods of time for later use in artificial insemination programs does not currently exist. Using molecular genetic techniques, activity levels of three compounds thought to be involved in the natural storage of sperm in the queen bee were measured over time. Results indicated that one compound (catalase) in particular may play an important role in sperm storage. This information will be used by other scientists and researchers involved in developing honey bee semen storage programs.
Honey bee sperm remains viable in the spermatheca of mated females for several years. During this time, the sperm retains respiratory activity, placing it at risk of the damaging effects of reactive oxygen species common to many biological processes. Antioxidative enzymes are known to combat this damage. Here we use quantitative real-time RT-PCR to establish gene-expression profiles in male and female honey bee reproductive tissues for three anti-oxidative enzymes, catalase, glutathione-s-transferase (GST), and superoxide dismutase (SOD). Catalase and GST show 10- to 20-fold transcript increases in the sperm storage organs of mated queens versus unmated queens, while SOD levels are high in both mated and unmated queens. Male reproductive and somatic tissues showed relatively high levels of antioxidant-encoding transcripts. All three enzymes screened were higher in mature males versus young males, although this effect did not appear to be confined to reproductive tissues and, hence, need not reflect a role in sperm storage. Further, antioxidant transcripts remained present, and apparently increased, in tissues long after sperm had matured and seminal fluid was available. The strong association between catalase and reproductive tissues in bees and other organisms suggests that this enzyme might play a strong role in antioxidative protection.