三疣梭子蟹精卵相互作用的扫描电镜观察  

Observation on the sperm-egg interaction of Portunus trituberculatus by scanning electron microscopy

作　　者：朱冬发[1] 王春琳[1] 薛良义[1] 余红卫[1] 

机构地区：[1]宁波大学生命科学与生物工程学院,浙江宁波315211

出　　处：《动物学报》2006年第1期196-201,共6页ACTA ZOOLOGICA SINICA

基　　金：国家自然科学基金(No.40576068);浙江省自然科学基金(No.301213);浙江省重大科技攻关项目(No.2004C12029);宁波市青年基金(No.2004A620014)资助~~

摘　　要：应用扫描电镜技术观察了三疣梭子蟹的精卵相互作用。未受精成熟卵表面较光滑、无受精孔,但有许多微孔。成熟卵外被卵膜,内为卵母细胞。在卵自然产出后,精子迅速发生顶体反应使顶体囊外翻并压入卵膜,而核仍留于卵膜外,核辐射臂不收缩且仍附着于卵膜上。三疣梭子蟹为多精着卵和多精入卵膜。精子外翻顶体囊压入卵膜后,核辐射臂陆续回缩直至消失。作用于顶体丝上的卵母细胞主动拖精作用对入卵膜精子的进一步入卵、受精至关重要,环状卵膜突起的向心伸展也有一定的协助作用。探讨了着卵精子的顶体反应。The sperm-egg interaction of the swimming crab Portunus trituberculatus was observed in detail by scanning electron microscopy （SEM）. The unfertilized mature egg is nearly spherical in form and about 300 btm in diameter. The mature egg is composed of two parts, the oocyte and the egg envelope. There are a large number of micropores on the smooth surface of the egg, and no micropyle is found. The nonflagellated and nonmotile sperm of Portunus trituberculatus attaches itself to the egg envelope randomly by its radial arms of nucleus, and undergoes the acrosome reaction immediately after natural ovulation. The acrosome reaction is induced by some excretion of the egg. Usually, a large number of sperms attach themselves to the surface of a single egg, and some of them can penetrate the egg envelop by acrosome reac- tion. During the sperm penetration of egg envelope, the everted acrosomal vesicle initially enter the egg envelope. The nuclear dish contracts, crumples its outer membrane, and often shows a central concave caused by the forward ejection of perforatorium and the subsequent reversal of acrosomal vesicle membrane. The attached radial arms don＇ t undergo withdrawal, and stay on the egg surface with the nucleus. Some attached sperms can also undergo acrosome reaction, but fail to penetrate the egg envelope, apparently because they are improperly oriented. Only after the everted acrosomal vesicle has penetrated the egg envelope do the radial arms undergo withdrawal and the nucleus subsequently enter the egg envelop. During the penetration of egg envelope by sperm nucleus, the ring-like projection of egg envelope formed around the nucleus progressively extends to the center. And when the sperm nucleus has penetrated the egg envelope completely, a penetration pore is left on the egg surface. The traction of oocyte is essential for the nucleus penetration of egg envelope, though the nucleus penetration of egg envelope is also thought to be aided by the centripetal extension of the projection of egg envelope.

关 键 词：三疣梭子蟹 精卵相互作用 扫描电镜技术 精子外翻 卵膜 

分 类 号：S917.4[农业科学—水产科学]