僧帽牡蛎二倍体和三倍体卵母细胞发育的超微结构比较

Ultrastructure comparison of development in oocytes of diploid and triploid oyster,Saccostrea cucullata

本文利用电子显微镜技术观察僧帽牡蛎二倍体和三倍体初级卵母细胞发育过程中细胞和细胞器的超微结构变化。结果表明 :二倍体和三倍体卵母细胞发育差异明显。在卵黄形成期 ,二倍体卵母细胞呈椭圆形 ,细胞核呈伪足状突起 ,核仁呈颗粒状聚合体 ,细胞器多发达 ,合成卵黄粒多 ,细胞膜外有微绒毛 ,卵母细胞生物合成旺盛、代谢活动强 ;而三倍体卵母细胞大都呈不规则形状 ,核仁小、致密 ,细胞器少且不发达 ,卵黄粒少 ,细胞膜外无微绒毛 ,卵母细胞生物合成及代谢弱。

Observation of ultrastructure of oocytes and various organellae is conducted for diploid and triploid oysters, Saccostrea cucullata , during their oocytes development using electronic microscope. The results indicate that oocytes development are obviously different for diploid and triploid oysters.During the period of vitellogenesis, oocytes of diploid oyster are oval shaped with pseudopodium-like processes nuclei, granular aggregation nucleoli,developed organellae and numerous yolk granellae in cyto plasm. Microvilli circle round oocytes. Biosynthesis and metabolism activate inside. In constrast,most oocytes of triploid are irregular shape,with small and dense nucleoli, a small amount of organellae and fewer yolk granules. No microvilli are observed outside oocytes . Weak biosynthesis and metabolism occur.