泥蚶（♀）×毛蚶（♂）受精及胚胎发育过程的初步研究

Preliminary study on fertilization and embryonic development of Tegillarca granosa (♀)×Scapharca subcrenata (♂)

中文关键词: 泥蚶  毛蚶  杂交  受精  胚胎发育

英文关键词: Tegillarca granosa  Scapharca subcrenata  Fertilization  Cross breeding  Embryogenesis

中文摘要:

      以泥蚶为母本、毛蚶为父本，运用同步催产法，同时收集泥蚶的卵和毛蚶的精子进行人工杂交，采用普通光镜和荧光显微镜，对泥蚶（♀）×毛蚶（♂）受精及胚胎发育的细胞学过程进行了连续观察。结果显示，毛蚶的精子可以附着并穿过泥蚶的卵膜进行受精，并激活卵子减数分裂使其释放第一极体(PB1)和第二极体(PB2)，能够形成雌、雄原核并发生原核联合，接着受精卵开始进行卵裂；杂交受精率统计为60.2%，发育速度较自交组慢；杂交胚胎发育前两次卵裂发育基本正常，后期才出现明显畸形；囊胚期持续时间很长，只能发育到担轮幼虫期，且纤毛越来越长，最后全部死亡。另外，在实验中发现有多精入卵和多极分离现象。

英文摘要:

      The fertilization experiment of Tegillarca granosa (♀)× Scapharca subcrenata (♂) was carried out three times at Qingjiang Field Research Station of Zhejiang Mariculture Institute in July, 2009. Consecutive cytological observation of fertilization and embryonic development of Tegillarca granosa (♀)× Scapharca subcrenata (♂) were conducted using both optical microscopy and fluorescence microscopy (Hoechst 33258 staining). The results show that sperm of S. subcrenata can attach to the surface of T. granosa eggs rapidly and the acrosomal reaction can be achieved successfully. Subsequently, the interspecifc sperm activated the meiosis of T. granosa egg and induced the releasing of PB1 and PB2. Then, the male and female pronuclei fused into zygotonuceus and the cleavage began subsequently. The rate of crossing fertilization was approximately 60.2％,and the early embryogenetic development of T. granosa (♀)× S. subcrenata (♂) was slower compared to those of intraspecific control groups, respectively. During the whole development process, the blastula stage was relatively long compared to that of control groups and the embryo was obviously abnormal, which may only reach trochophore stage and died before D shaped larva stage. Trochophore larva of T. granosa (♀)× S. subcrenata (♂) were found to keep excessive cilia growth. In addition, polyspermy and multiple separations were observed in this experiment