中国雨蛙精子结构及其在系统发育上的意义

THE STRUCTURE OF THE SPERMATOZOON OF Hyla chinensis AND ITS BEARING ON PHYLOGENY

研究了中国雨蛙（Ｈｙｌａｃｈｉｎｅｎｓｉｓ）精子的超微结构，并初步探讨其在系统发育上的意义。中国雨蛙精子由头部和尾部两部分组成。头部有一棒状的细胞核，核内染色质高度浓缩。细胞核前方有顶体。顶体圆锥状。顶体下腔之中有一圆锥状的顶体下锥和细小的囊泡。精子尾部细长，主要由轴丝、致密纤维和线粒体组成。尾部没有波动膜。从蟾蜍科、雨蛙科和蛙科的精子结构看，无尾两栖类在进化过程中，精子结构趋向简单。雨蛙科精子的结构介于蟾蜍科和蛙科之间，更接近蟾蜍科。在雨蛙科中，与已经研究过的雨蛙科的其他种类相比，中国雨蛙的精子结构较为简单，因此似更为高等。精子尾部波动膜的消失和附属纤维数量的减少似可认为是中国雨蛙的进化特征之一。

The ultrasturcture of the spermatozoon of Hyla chinensis was studied in this paper and its significance on the phylogenesis was roughly inquired.The spermat ozoon consisted of a head and a tail.In the head there was a stick like nucleus with highly condensed chromatin in it.A cone shaped acrosome lied anterior to the nucleus.There was a subacrosomal cone and some small vesicles within the sub acrosomal space.The tail of the spermatozoon was thin and long.It consisted of a n axoneme,a dense fiber and mitochondria,but without an undulating membrane.Ba sed on the fine structure of the spermatozoa of Bufonidae,Hylidae and Ranidae w hich had been studied so far,it was suggested that during the evolution of anur an amphibian the structure of the sperm tended to simplify.The complexity of the sperm structure of Hylidae was situated between Bufonidae and Ranidae,but was more similar to that of Bufonidae.Within Hylidae,the structure of the spermatoz oon of Hyla chinensis was simpler than that of other species which had been studied in Hylidae.It was suggested that the reduction of the undulating membran e and the reduction (or the fusion) of the accessory fibers in the spermatozoon tail could be considered as advanced features of Hyla chinensis .