异源精子诱导栉孔扇贝雌核发育早期胚胎发育及其倍性分析

采用紫外线遗传灭活的长牡蛎（Crassostrea gigas）精子作激活源,经6-DMAP加倍诱导栉孔扇贝（Chlamys farreri）第二极体抑制型雌核发育二倍体;运用荧光显微技术,对雌核发育二倍体卵子早期胚胎发育过程中的核相变化进行观察。结果显示,紫外线处理过的精子入卵后发生一次轻微膨胀,形成雄性原核,但不形成染色体,而是浓缩为致密的染色质小体（DCB）,DCB或滞留于两卵裂球的分裂沟上或进入其一的细胞质中,不与雌原核融合;雌核发育胚胎的发育速度明显滞缓,经6-DMAP处理后胚胎发育速度加快,发育同步化;在雌核发育二倍体诱导过程中,还观察到杂交体、异源三倍体、雌核发育单倍体、雌核发育四倍体。结果为异源精子诱导栉孔扇贝雌核发育提供了细胞学证据。

Studies on pro-embryo development and the ploidy of gynogenesis induced by heterologous sperm in the scallop,Chlamys farreri

Gynogenetic diploid eggs by inhibiting the second polar body with 6-DMAP in Chlamys farreri were induced by genetically inactivated Crassostrea gigas sperms with ultraviolet.We observed nuclear behaviors of its gynogenetic embryos using fluorescent micro-technique during its early developmental stages.According to cytological observation,the ultraviolet-irradiated sperm nucleus could gently expand once after incorporating into egg and developed into a male pronucleus,but could not form chromosomes and became a dense chromatin body(DCB).DCB was seen either in the region of the furrow or in the cytoplasm of the blastomere,but could not fuse with the female pronucleus.The developmental progress of gynogenetic embryo was seriously delayed,but when added 6-DMAP,comparing with gynogenetic diploid,the developmental progress of gynogenetic diploid embryo was quickened and was also synchronous.In this study, we also reported and analyzed the embryo with complicated ploidy yielded in gynogenetic diploid group,besides gynogenetic diploid,there were hybrid,heterologous triploid,gynogenetic haploid,gynogenetic tetraploid,etc.Cytological evidence of gynogenesis in Chlamys farreri induced by heterologous sperm was demonstrated.