Bakst M R, Bauchan G
Animal Biosciences and Biotechnology Laboratory
Electron and Confocal Microscopy Unit, Beltsville Area, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705.
Poult Sci. 2016 Apr;95(4):948-55. doi: 10.3382/ps/pev440. Epub 2016 Jan 14.
Mammalian sperm bind to terminal carbohydrates associated with glycoconjugates on the apical surface of oviduct epithelial cells in the caudal region of the oviduct and undergo cellular and molecular modifications associated with capacitation prior to ovulation. In contrast, chicken sperm are stored for up to 23 d in sperm-storage tubules (SST) localized in the uterovaginal junction (UVJ). Little is known of the cellular and molecular mechanisms that regulate sperm storage in and release from the SST. The purpose of this study was to identify glycoconjugates associated with the SST epithelial cell surface using lectins. Virgin hens and hens of higher and lower fertility in egg production for 6 to 16 wk were used in this study. Sections of UVJ mucosa containing SST were stained with fluorescent conjugated lectins and examined by confocal microscopy. Carbohydrate moieties associated with the UVJ and SST epithelia differed in their lectin binding patterns. No differences in the lectin binding patterns within the 2 epithelia were discernible between the virgin and younger and older hens. Minor differences were observed between the higher and lower fertility hens. Only lectins specific for galactose and N-acetylgalactosamine moieties were localized to the luminal surface of the SST. While resident sperm may be closely apposed to the SST epithelial cell apical microvilli, it is unlikely that sperm binding to the microvilli via terminal carbohydrates associated with glycoconjugates is a requisite for prolonged storage. However, the possibility of SST epithelial cell communication with resident sperm via shedding microvillous vesicles characterized by surface glycoconjugates with terminal galactose and N-acetylgalactosamine moieties is currently being investigated.
哺乳动物的精子会与输卵管尾端区域上皮细胞顶端表面的糖缀合物相关的末端碳水化合物结合，并在排卵前经历与获能相关的细胞和分子修饰。相比之下，鸡的精子会在位于子宫阴道交界处（UVJ）的精子储存小管（SST）中储存长达23天。目前对于调节精子在SST中储存和释放的细胞和分子机制知之甚少。本研究的目的是使用凝集素来鉴定与SST上皮细胞表面相关的糖缀合物。本研究使用了处女母鸡以及产蛋6至16周、繁殖力高低不同的母鸡。含有SST的UVJ黏膜切片用荧光共轭凝集素染色，并通过共聚焦显微镜检查。与UVJ和SST上皮相关的碳水化合物部分在凝集素结合模式上有所不同。在处女母鸡以及年轻和年长母鸡之间，这两种上皮内的凝集素结合模式没有差异。在繁殖力高低不同的母鸡之间观察到了细微差异。只有对半乳糖和N - 乙酰半乳糖胺部分具有特异性的凝集素定位于SST的腔表面。虽然驻留精子可能与SST上皮细胞顶端微绒毛紧密相邻，但精子通过与糖缀合物相关的末端碳水化合物与微绒毛结合不太可能是长期储存的必要条件。然而，目前正在研究SST上皮细胞通过脱落以具有末端半乳糖和N - 乙酰半乳糖胺部分的表面糖缀合物为特征的微绒毛小泡与驻留精子进行通讯的可能性。
