紫外辐射对栉孔扇贝精子遗传失活及形态结构的影响

Effects of ultraviolet irradiation on genetic inactivation and morphological structure of sperm of scallop Chlamys farreri

报道了紫外辐射对栉孔扇贝精子遗传失活及形态结构的影响。采用光照强度为800μW/cm2·s的紫外线辐射40～50s的栉孔扇贝精子,与正常的卵子受精可以得到雌核发育的单倍体胚胎。随着辐射时间的增加,受精率明显下降,且受精卵极少发育到D形幼虫。扫描电镜观察发现,辐射后部分精子的顶体膜破裂,顶体丝伸出,辐射时间越长顶体受到的破坏越严重,证明紫外辐射可以诱导精子的顶体反应;精子的鞭毛在紫外辐射过程中也会受到破坏,随着辐射时间的增加鞭毛脱落的比例也逐渐增加。推测紫外辐射导致精子结构的破坏是受精率下降的原因之一。

Effects of ultraviolet irradiation on genetic inactivation and morphological structure of sperm were examined in scallop Chlamys farreri. The sperm irradiated for 40 - 50s at the inten-sity of 800μW/cm2·s were used to inseminate with eggs that haploidy embryos of gynogenesis were successfully obtained. The fertilization rate was apparently decreased with increasing irradiation time, and a tiny minority of fertilized eggs developed into D-shape larve. Scanning electron mi-croscopy (SEM) observation showed that after irradiated by UV, the acrosome membranes of some of sperm were cracked,and acrosome substances were released to form acrosome filament. As the du-ration of UV-irradiation increased, the acrosome tended to suffer greater damage. Experimental re-sults indicated that UV irradiation induced acrosome reaction. The flagella were also destroyed by UV irradiation, and the rate of sperm with flagellum-lost increased with increasing the irradiation duration. It was estimated that destruction of sperm after UV-irradiated was one of the factors for the decline of fertilization.