蓝尾石龙子精子的超微结构

蓝尾石龙子(Eumeces elegans)附睾以2．5％戊二醛和1％锇酸双重固定，按常规制作超薄切片，用H-600透射电镜研究观察精子的超微结构。精子由头部和尾组成，头部由顶体复合体和核组成，尾由颈段、中段、主段和末段组成。头部的顶体囊前部扁平，分为皮质和髓质，顶体下锥由类结晶状的顶体下物质组成，穿孔器顶端尖，、穿孔器基板塞子状，细胞核延长，核内小管缺，核伸展部前端具一电子透明区，核肩圆，核陷窝锥形。颈段具片层结构，近端中心粒和远端中心粒的长轴呈直角，9束外周致密纤维与远端中心粒相应的9束三联微管相联，向后与轴丝相应的9束双联微管相联，中央纤维与2个中央单微管相联。中段短，含有线状嵴的柱状线粒体，由连续的规则小卵状或小梯形致密体组成线粒体间的环状结构，纤维鞘伸入中段，终环紧贴于细胞膜的内表面。线粒体与环状结构的模式为：rs1／mi1，rs2／mi2，rs3／mi3，rs4／mi4，横切面上每圈线粒体数目为10个。主段前面部分具薄的细胞质颗粒区。纤维3和8至主段前端消失。轴丝复合体呈“9 2”型。蓝尾石龙子精子超微结构与已描述的石龙子科种类比较发现，与蜓蜥群和胎生群的石龙子相似；但没有发现石龙子科精子的独征。

Ultrastructure of Spermatozoa of Eumeces elegans

We studied the ultrastructure of epididymal spermatozoa of Eumeces elegans.After epididymal tissues of E.elegans were double fixed with 2.5% glutaric dialdehyde and 1% osmic acid,the ultrathin section were observed under H-600 transmission electron microscopy.The spermatozoa contain two major components,a head and a tail.The head contains an acrosomal complex and a nucleus,and the tail a neck,a midpiece,a principal piece and an endpiece.The mature spermatozoa are characterized by:a depressed acrosome at the anterior portion;an acrosomal vescile divided into cortex and medulla;a subacrosomal cone filled with paracrystalline subacrosomal material;a pointed prenuclear perforatorium;a stopper-like perforatorium base plate;an elongated nucleus;an epinuclear lucent zone;rounded nuclear shoulders;a coned nuclear fossa;a bilateral stratified laminar structure within neck region;absence of a endonuclear canal;a long axis of the proximal centriole almost vertical to that of the distal centriole;nine peripheral dense fibres connecting inward with the corresponding 9 triplets of the distal centriole,and backward with the doublets of the axoneme;central fibres connecting with the two central singlets;a short midpiece;columnar mitochondria with linear cristae;each intermitochondrial ring structure consisting of the complete ring of small regularly ovoid or small trapezoid dense bodies;a fibrous sheath into the midpiece;an annulus closely attached to the inner surface of the plasma membrane;the arrangement pattern of the ring structure and mitochondria in rs1/mi1,rs2/mi2,rs3/mi3,and rs4/mi4;mitochondria in order of 10 in transverse section;a thin zone of cytoplasm at the anterior portion of the principal piece;the enlarged fiber 3 and fiber 8 disappearing at the anterior portion of the principal piece;the axoneme complex having an usual 9 2 pattern.The sperm ultrastructure of E.elegans is similar to that of the species within the Sphenomorphus and the Egernia groups,but evidence of spermatozoal autapomorphies is not found in E.elegans.