【作者】 甘光明；

【导师】 张耀光；

【作者基本信息】 西南师范大学 ， 动物学， 2003， 硕士

【摘要】 对唇(鱼骨)受精过程中发生的主要事件进行组织切片、透射和扫描电子显微镜观察，结果表明： 精孔器属深凹陷、短孔径型，精孔管一次只能通过一个精子。精子在受精2s到达精孔管，3s进入卵子，5s形成精子星光，20s形成受精塞，60s后精孔器内精子开始溶解。有多精入卵现象，极少数卵子多精受精。受精240s，在动物极初步形成盘状胚盘，胚盘逐渐扩大、隆起。受精5min，精子从细胞质凹陷区逸出。受精8-15min，进入第二次减数分裂后期。受精20min，进入第二次减数分裂末期，放出第二极体。25min，雌雄原核形成。30-35min，雌性原核向雄性原核移动。40-50min，雌雄原核结合。受精60min，胚盘隆起最高。70min，合子核进入第一次有丝分裂中期。80min，染色体处于有丝分裂后期。120min，染色体处于有丝分裂末期，分裂沟形成，受精卵径裂为二细胞。受精140min，再径裂为4细胞。 唇(鱼骨)卵膜由初级卵膜和次级卵膜组成，初级卵膜具三层辐射带，带内具弯曲的弹性亚膜和辐射管，次级卵膜胶质状，外具浓密的颗粒。受精80s，弹性亚膜弯曲的角度增加，110s，第一层辐射带的弹性亚膜拉直，240s，第一层和部分第二层辐射带弹性亚膜倾斜，第三层辐射带弹性亚膜拉直，受精膜(卵膜)开始外举，140min受精膜完全举起。受精膜外举是三层辐射带相对滑动的结果。 在光镜下，胚盘附近有嗜酸性和嗜碱性两种卵黄，其内部或侧边多具小泡或泡状缺口。卵黄有4种降解途径：随胞质流悬浮于细胞质中，在细胞质中直接降解。内部形成小泡，卵黄从内部小泡开始碎裂、降解。外部形成弧形缺口，卵黄从弧形缺口开始碎裂、降解。卵黄外被囊泡，卵黄颗粒在小泡内进行降解，残存的颗粒将随囊泡以胞吐的形式排于卵周隙。 皮层小泡1-4层，在光镜和透射电镜下均具5种形态，由外及内，小泡内颗粒的直径逐渐减少。皮层反应可分为潜伏期、发展期、高潮期、衰退期，20s开始于动物极低纬度区，稍后出现在精孔器前庭附近，随后在这两个始发区向四周扩散。皮层小泡分批多次释放，质膜也多次发生重组。 卜何对卜N．）十物’I：他地 仰排原核纪合是精人己光扩怅、引＃和细W质流动儿D。州引】的结果。本义提出了粉厂入卵凡能们说，以如释多余入如精厂火I＼山冰 k］。更多还原

【Abstract】 The fertilized eggs of Hemibnrbus lubco have been observed by SEM, TEM and OM, and main events of fertilization biology have been studied, too. The results suggest:The micropylar apparatus, being composed of vestibule and micropylar tube, is deeply sunken with a short tunnel. External diameter of the micropylar tube is 2. 512 m, and its interior diameter is 2. 330 m, The diameter of sperm is 1. 567 m. Before sperm penetrates, the chromosomes are at metaphase, following prophase and preceding anaphase, during which the chromosomes are aligned along the metaphase plate. About 2s after fertilization in 17 , sperms arrive at micropylar tube; 3s, sperm penetrates into ovum where cytoplasm is sunken; 5s, the spermaster come into being; 20s, fertilization stopper appears; 60s, sperms in micropylar apparatus begin to disaggregate. Now and then, there exists the phenomenon that a few sperms penetrate into egg, while polyspermy is few. 240s, the blastoderm forms in animal hemisphere; 5min, sperm deviates from the sunken area; 8-15min, the chromosome are at anaphase, and 20min, at telophase of meiosis, later, the second polar body can be seen to be expelled; 25min, both the male pronucleus and the female pronucleus can be seen; 30-35min, the female pronucleus move towards the male pronucleus, at the same time, both the pronucleuses move towards the pivot of blastoderm; 40-50min, both the pronucleuses are conjugated into zygote, and then, the zygotic nucleus expands; 70min, chromosomes are situated at metaphase of the first karyokinesis, 80min, at anaphase, and 120min, at telophase, the oosperm is segmentalized into daughter cells. 140min, chromosomes of the daughter cells are situated at metaphase of the second karyokinesis, while the daughter cells don’t separate.The egg envelopes are composed of secondary envelope and primary envelope which comprise zona radiatal, zona radiata2 and zona radiata3, and there are tube radiata and flexural sub-elasticity envelope which is vertical with plasma membrane in every zona radiata. About 80s after fertilization, the angle of sub-elasticityenvelope expands. 110s, sub-elasticity envelope in zona radiatal becomes parallel with plasma membrane, later, the same phenomenon happen in zona radiata2 and zona radiata3, which result in the fertilization envelopes (egg envelopes) outspreading; 140min after fertilization, the fertilization envelopes come into being. Three of the zona radiatas gliding together result in fertilization envelopes dilating.There are two types of yolk granule inside of ovum, in which vesicle or arc gap could be observed by OM, and the yolk granule has been decomposed by 4 pathway: (l).be decomposed straight in cytoplasm; (2).begin to be decomposed from the vesicle inside of yolk; (3).begin to be decomposed from the arc gap of yolk; (4).before decomposed, the yolk will be enwrapped by envelope.There are 1 to 4 rows and five types of cortical alveoli in the cortex of Hemibarbus labco. egg From inner to outer of the cortex, the diameter of cortical alveoli decreases gradually. Cortical reaction comprises latent period, developmental period, climactic period and declining period. About 35s after fertilization, a few cortical alveoli begin to discharge from the low-latitudes of the animal hemisphere, later, the same pross happens in the near of micropylar apparatus, and then cortical reaction extends to the animal hemisphere and the vegetal hemisphere. 55s-5min after fertilization, most of cortical alveoli discharge in the animal hemisphere, and the residual cortical alveoli will entirely discharge in 15min. While cortical alveoli discharge in batches, the plasma membrane has been reorganized time after time.Spermaster’ elongate and traction, and Cytoplasm’ flowage make the male pronucleus and the female pronucleus conjugate. This paper puts forward a hypothesis that sperm will consume energy while entering into ovum to explain the contabescence of the sperm.更多还原