Author
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Bakst, Murray |
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Bauchan, Gary |
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Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/15/2015 Publication Date: 1/14/2016 Citation: Bakst, M.R., Bauchan, G.R. 2016. Lectin staining of epithelia lining the uterovaginal junction and sperm-storage tubules in chicken hens. Poultry Science. 95:948-955. Interpretive Summary: Located at the upper end of the chicken hen’s vagina are numerous tubular structures derived from the vagina’s surface cells, collectively referred to as the sperm-storage tubules (SSTs). Following mating or artificial insemination, sperm ascend the vagina and enter the SSTs. Over the next days and weeks the sperm gradually exit the SSTs and are transported to the upper end of the oviduct to fertilize a daily succession of ova (yolks). Little is known regarding the cellular and molecular interactions between the cells comprising the SST and sperm within the SST. In preparation for fertilization, mammalian sperm bind to various sugars associated with proteins and lipids (glycoproteins and glycolipids) on the surface of their oviductal cells. We used fluorescent-labeled probes to determine if similar glycoproteins and glycolipids are associated with the surface of the cells lining the SST. We found two sugars (galactose and N-acetylgalactosamine) on the surface of the cells lining the SSTs that are known to bind mammalian sperm to oviductal cells. The number of weeks the hens was in egg production, higher and lower fertility hens, and whether the hens were virgins or not had minor influence on the probes binding patterns in the hens SST and surrounding tissues. Future work will be conducted to determine if sperm do bind to the cells lining the SSTs. These observations will benefit poultry scientists studying the biological basis of prolonged oviductal sperm storage and sustained hen fertility. Technical Abstract: In most mammals sperm are subject to a transient storage period in the caudal region of the oviduct during which they undergo cellular and molecular modifications associated with capacitation. During this storage period sperm bind to a terminal carbohydrate moiety associated with a glycoconjugate on the apical surfaces of oviduct epithelial cells. In contrast, chicken sperm are stored for up to 23 days in sperm-storage tubules (SSTs) that are localized in the uterovaginal junction (UVJ). Little is known of the cellular and molecular mechanisms that regulate sperm retention in and release from the SSTs. The primary purpose of this study was to identify glycoconjugates associated with the SST epithelial cell surface using a battery of lectins. Virgin broiler hens and hens of higher and lower fertility in egg production for 6 to 16 wk were used in this study. Fixed UVJ mucosa containing SST were sectioned and stained with fluorescent conjugated lectins and examined with a confocal microscope. Carbohydrate moieties associated with the UVJ and SST epithelia differed in their lectin binding patterns. No differences in the lectin binding patterns within the two epithelia were discernible between the virgin, and younger and older hens and only minor differences were observed with one lectin between the higher and lower fertility hens. Only lectins specific for galactose and N-acetylgalactosamine moieties were localized to the luminal surface of the SSTs. However, the role, if any, of these two carbohydrates in sperm binding the SST apical surface is not known. Unlike mammals where a sperm binds to an oviduct epithelial cell, potentially large numbers of sperm can be stored in each SST thereby limiting the access of sperm to the SST apical epithelial surface. Whether sperm within the SSTs actually bind to glycoconjugates with terminal galactose and N-acetylgalactosamine moieties will be determined in future studies. |
