优雅蝈螽精子形成过程中核的形态结构变化观察

摘要

[目的]螽斯精子结构复杂,具有特征性的箭头状顶体,是研究昆虫精子形成的理想材料.为了研究螽斯精子形成过程中的动态变化机制,特别是细胞核的凝集机制和箭头状顶体的发生机制,本研究对优雅蝈螽Gampsocleis gratiosa精细胞和精子的细胞核进行了观察.[方法]选择发育良好的优雅蝈螽成虫精巢为研究材料,利用透射电镜技术、普通光学显微镜和荧光显微镜技术,制作光镜切片和电镜切片进行观察.[结果]根据其形态结构变化特征,将优雅蝈螽精子形成过程中的细胞核分为4个阶段:圆形核、叶形核、柱状核和成熟阶段.我们还通过常规HE染色,结合DNA特异性荧光探针DAPI,证明了圆形核时期,精细胞内具有两个明显的球状结构,一个为细胞核,另一个是原顶体;精子成熟阶段,精子尾部排出的细胞质微滴中含有DNA.[结论]优雅蝈螽精子形成过程中,精细胞的细胞核经历了显著的形态变化,精细胞核的形态变化与细胞骨架微管相关,细胞核塑形伴随着染色质的重组.本研究为进一步阐明直翅目昆虫精子形成的分子机制奠定了基础.%[Aim] The distinctive arrow-shaped morphology and large size of the spermatozoa of Gampsocleis gratiosa makes it a useful model to explore spermiogenesis in Tettigoniidae.In order to better understand the mechanism of spermiogenesis,especially the mechanism of nucleus morphogenesis and arrow-shaped acrosome formation in katydids,the nuclei of spermatid and spermatozoa of G.gratiosa were observed in the present study.[Methods] The testes of G.gratiosa in sexually mature males were used as the materials.We observed the nuclei of spermatid and spermatozoa by transmission electron microscopy,ordinary optical microscopy,fluorescence microscopy and with H&E and DAPI (DNA specific probe) staining method.[Results] According to the morphology and structure,the nuclei during spermiogenesis of G.gratiosa were divided into four phases:rounded,leaf,prismatic and mature phases.During the spermiogenesis of G.gratiosa,there are two globular structures at the rounded phase,one is the nucleus and the other is pro-acrosome.The cytoplasm droplet,which would be derelict along the tail of spermatozoa at the mature phase,contains DNA.[Conclusion] The observation revealed that spermatid nucleus of G.gratiosa undergoes dramatic morphological changes during its spermiogenesis.The nucleus shaping is driven by cytoskeletal microtubules,and the chromatin reorganization is together with nucleus shaping.This study will be the foundation to clarify the molecular mechanism of spermiogenesis in Orthoptera.