Ichikawa Yoshinobu, Matsuzaki Mei, Mizushima Shusei, Sasanami Tomohiro
Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan.
United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
J Poult Sci. 2017 Jan 25;54(1):80-86. doi: 10.2141/jpsa.0160088.
Fertilization is indispensable for zygotic formation leading to the birth of animals and the species-specific sperm-egg binding thought to be the initial step in this important process. In birds, the oocyte, which encounters the spermatozoa at the time of fertilization, is enclosed in a perivitelline membrane (pvm) constructed of several zona pellucida glycoproteins (ZP proteins: ZP1, ZP2, ZP3, ZP4 and ZPD). The aim of this study was to determine the ZP protein in the pvm responsible for sperm-pvm binding in Japanese quail. We tested the effects of anti-ZP protein antibodies on sperm perforation in the pvm. The results showed that the anti-ZP1 and ZP3 antibody significantly blocked hole formation by sperm, whereas anti-ZP2, ZP4 and ZPD as well as normal rabbit serum had no such effect. When the sperm acrosome reaction was inhibited in the presence of pertussis toxin, sperm-pvm binding was observed. This sperm-pvm binding was significantly prevented when the purified ZP1 or ZP3 was included in the reaction mixture. Moreover, both digoxigenin-labeled ZP1 and ZP3 were found to interact with the sperm head by immunocytochemical observation. Our results indicate that sperm binding to the pvm is, at least in part, mediated by the interaction of ZP1 and ZP3 with the sperm head during fertilization in Japanese quail.
受精对于合子形成至关重要，而合子形成是动物诞生的前提，物种特异性的精卵结合被认为是这一重要过程的起始步骤。在鸟类中，受精时与精子相遇的卵母细胞被包裹在由几种透明带糖蛋白（ZP蛋白：ZP1、ZP2、ZP3、ZP4和ZPD）构成的卵周膜（pvm）中。本研究的目的是确定日本鹌鹑卵周膜中负责精子与卵周膜结合的ZP蛋白。我们测试了抗ZP蛋白抗体对精子穿透卵周膜的影响。结果显示，抗ZP1和ZP3抗体显著阻断了精子形成孔洞，而抗ZP2、ZP4和ZPD以及正常兔血清则没有这种作用。当在百日咳毒素存在的情况下抑制精子顶体反应时，观察到精子与卵周膜的结合。当反应混合物中包含纯化的ZP1或ZP3时，这种精子与卵周膜的结合被显著阻止。此外，通过免疫细胞化学观察发现，地高辛标记的ZP1和ZP3均与精子头部相互作用。我们的结果表明，在日本鹌鹑受精过程中，精子与卵周膜的结合至少部分是由ZP1和ZP3与精子头部的相互作用介导的。
