|Blomberg, Le Ann|
Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2010
Publication Date: 7/5/2011
Citation: Foye-Jackson, O., Long, J.A., Bakst, M.R., Blomberg, L., Akuffo, V.G., Silva, M.V., Guthrie, H.D., Mcmurtry, J.P. 2011. Oviductal expression of avidin, avidin-related protein-2 and progesterone receptor in turkey hens in relation to sperm storage: effects of oviduct tissue type, sperm presence, and turkey line. International Journal of Poultry Science. 90:1539-1547. Interpretive Summary: The genetic basis of sperm storage activity in the sperm storage tubules (SST) of the turkey hen is unknown. Previous studies in our laboratory demonstrated that approximately 1% of genes are differentially expressed in the reproductive tracts of sperm-inseminated (AI) versus sham-inseminated (SI) turkey hens. In particular, avidin mRNA expression was up-regulated (3-fold) in the SST of AI hens compared to SST of SI hens, suggesting that the presence of sperm may play a role in oviductal avidin expression and that the protein avidin may be important to the sperm storage function of the SST. In the current study, we show that avidin expression appears to be line and tissue specific. For the Converter turkey hen, the presence of sperm in the oviduct increased avidin mRNA expression in the SST and surface epithelium of the UVJ. For the Grademaker hen, avidin protein expression was more evident in the SST of the SI hen relative to the SST of AI hens. While this qualitative assessment can be made, interpretation of this data is difficult due to the lack of information regarding avidin protein turnover and post-translational modification within the uterovaginal tissues. Our data strongly suggests differential gene and protein expression of avidin, and avidin related genes in the turkey oviduct between the UVJ and VGE and turkey lines, additional studies are needed to better characterize the turkey avian model to provide a stronger foundation for future genomic and proteomic parallel studies.
Technical Abstract: The turkey hen’s sperm storage tubules (SST), located in the uterovaginal junction (UVJ) of the oviduct, maintain viable sperm for up to10 weeks after a single insemination. The mechanisms of this in vivo sperm storage are poorly understood. Our objective was to evaluate mRNA and protein expression of avidin and two avidin-associated factors, avidin-related protein-2 (AVR2) and progesterone receptor (PR), in the oviducts of two different lines to determine the extent to which they were sperm-responsive and tissue specific. At 38 weeks of age, Hybrid Grademaker (GM) and Converter (CN) turkey hens were artificially inseminated with diluted semen (AI) or sham-inseminated with extender alone (SI). Forty-eight h after insemination, total RNA was extracted from the UVJ SST and adjoining vaginal epithelium (VGE) of SI and AI hens. Real time-polymerase chain reaction (RT-PCR) data showed a clear tissue region specific effect on gene expression in the turkey hen oviduct with much greater (P < 0.0001) expression in the UVJ compared to VGE region for avidin and AVR2 mRNA in both lines and PR mRNA in the CN line. In contrast to RT-PCR data, in situ hybridization of SI and AI tissues showed that the presence of sperm increased avidin mRNA in the SST and surface epithelium in the UVJ of CN hens. Immunohistochemistry confirmed the presence of avidin protein in the epithelium of the UVJ in both lines; however, while avidin protein was localized in the SST of SI GM hens, this protein was not detected in SST of CN hens. The up-regulation of avidin and AVR2 mRNA within the sperm storage region indicates involvement of avidin and perhaps avidin analogs in the sustained storage of sperm in the SST, possibly through biotin binding to avidin. The absence of avidin protein in the SST and VGE of CN hens in the presence of increased mRNA may indicate a rapid turnover of protein.