中国石龙子成熟精子的超微结构

利用透射电镜观察中国石龙子附睾成熟精子的超微结构。顶体囊前部扁平、由皮质和髓质组成 ,穿孔器中度倾斜、顶端尖 ,穿孔器基板塞子状 ,细胞核长形 ,核内小管缺 ,核前电子透亮区小 ,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 ,多层膜结构缺 ,含有线状嵴的柱状线粒体 ,不规则卵状致密体组成不连续的环状结构 ,纤维鞘伸入中段 ,具终环。线粒体与环状结构的模式为 :rs1 /mi1 ,rs2 /mi2 ,rs3/mi3,rs4 /mi4。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。轴丝呈“9 2”型。中国石龙子精子超微结构具有塞子状的穿孔器基板、致密体形成不连续的环状结构和纤维鞘始于ms2等特征与巨石龙子群和蜓蜥 -胎生群不同。没有发现石龙子科精子的独征

Ultrastructure of spermatozoa of the Chinese skink Eumeces chinensis

We studied the ultrastructure of epididymal spermatozoa of Chinese skinks Eumeces chinensis (n = 8) collected in April 2003 from a population in Lishui, Zhejiang, eastern China. The mature spermatozoa are characterized by: a depressed acrosome at the anterior portion; an acrosomal vescile divided into cortex and medulla; a moderately oblique prenuclear perforatorium with a sharp tip; a stopper like perforatorium base plate; an elongated nucleus; absence of a endonuclear cannal; an obscure epinuclear lucent zone; rounded nuclear shoulders; a coned nuclear fossa; a bilateral stratified laminar structure within neck region; 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; absence of multilaminar membranes; columnar mitochondria with linear cristae; each intermitochondrial ring structure consisting of the incomplete ring of irregularly ovoid dense bodies; a fibrous sheath into the midpiece; presence of an annulus; the arrangement pattern of the ring structure and mitochondria in rs1 / mi1, rs2 / mi2, rs3 / mi3, and rs4/mi4; a thin granular 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 of E. chinensis characteristically has a stopper like perforatorium base plate, incomplete rings constructed by dense bodies, a fibrous sheath starting from mi2. These traits are absent in species within the Sphenomorphus Egernia group and the Eugongylus group. Thus, we conclude that the sperm of E. chinensis differs from that of the aforementioned two skink groups. Evidence of spermatozoal autapomorphies is not found in sincid skinks .