Hydrozoan eggs can be fertilized only at the site of polar body formation and first acquire this ability during second polar body formation. The eggs of Aequorea victoria form a discrete Triticum lectin binding moiety in the jelly coat near the first polar body as it is being given off and also a discrete concanavalin A binding moiety associated with the egg surface where the second polar body forms, which disappears immediately after fertilization. The germinal vesicle has an eccentric position in full grown Aequorea oocytes. The region of oocyte surface closest to the germinal vesicle is the site where the polar bodies normally form. When oocytes are centrifuged during oocyte maturation, the meiotic apparatus sometimes shifts to a different position with reference to the egg surface and polar bodies are given off at this new site. There is a corresponding shift in the position of the Triticum and concanavalin A lectin binding moieties, indicating that their formation is associated with local events occurring at the site of polar body formation. Treatment of Aequorea eggs with Triticum or concanavalin A causes a marked reduction in the ability of these eggs to be fertilized, suggesting that sugar-containing moieties, to which the lectins bind, play a role in fertilization. Removal of sugars on these moieties with mannosidase or N-acetylglucosaminidase, or the cleavage of the protein the sugars are attached to with trypsin, results in eggs that do not bind Triticum or concanavalin A and also show a marked reduction in the ability to be fertilized. These experiments suggest that the lectin binding moieties are glycoproteins.

译文

虫卵只能在极体形成的部位受精,并在第二极体形成期间首先获得这种能力。维多利亚水母虫的卵在被释放时在第一极体附近的果冻外壳中形成离散的小麦凝集素结合部分,并且还与蛋表面相关的离散的伴刀豆球蛋白A结合部分形成第二极体,该表面立即消失。受精后。生水泡在成年的水母卵母细胞中有一个偏心的位置。卵母细胞表面最接近生发囊泡的区域是极体正常形成的部位。在卵母细胞成熟过程中对卵母细胞进行离心分离时,减数分裂装置有时会相对于卵表面移动到其他位置,并且在这个新位置释放出极体。小麦和伴刀豆球蛋白A凝集素结合部分的位置有相应的变化,表明它们的形成与在极体形成部位发生的局部事件有关。用小麦或伴刀豆球蛋白A处理水母乳卵会导致这些卵受精的能力显着降低,这表明凝集素所结合的含糖部分在受精中发挥了作用。用甘露糖苷酶或N-乙酰氨基葡糖苷酶去除这些部分上的糖,或用胰蛋白酶裂解糖所附着的蛋白质,导致卵不结合小麦或伴刀豆球蛋白A,并且受精能力显着降低。 。这些实验表明凝集素结合部分是糖蛋白。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录