拟异蚖和古蚖精子的超微形态和精子形成的研究(原尾目:古蚖科)

余山拟异蚖和3种古蚖的精子均为扁圆形,未见顶体,线粒体集中在一侧;核呈环形、边位、中部由膜状体分布其间.领结古蚖的早期精细胞为球形,染色质凝集成团,继而核中裂并沿细胞赤道逐渐围绕成环,染色质呈细沙状,胞间有“桥”相通.核膜一端开始内陷,出现黑点.待发育到中期精细胞,这些黑点逐渐形成奇特的管状核膜陷体;染色质变成短线形,随后排成4—5行.线粒体颗粒状,细胞间仍有“桥”连通.晚期精细胞的染色质凝集成粗带,最后形成光滑质密的核,而多余的核物质,一段一段从精子一端脱离,形成一串孢囊状体夹在精子之间,待精子成熟游离时,这些孢状体分散开来.从观察结果表明拟异蚖精子与古蚖的非常相近.

THE ULTRASTRUCTURE OF SPERMATOZOA AND SPERMIOGENESIS IN EOSENTOMON AND PSEUDAMSENTOMON (PROTURA: EOSENTOMIDAE)

The fine strustures of the spermatozoa of Psendanisentomon sheshanensis, Eosentomon sollaru.E.breuicorpusculum and E. asahi were observed,and the spetmiogenesis of E.colla-nim was studied. Their mature spermatozoa are all discoidal and devoid of flagella, similar to hat of Hovntomon transitorinm,but slightly saried in size.Theuucleus is a flat cing at the peripheral aren in cach sperm,and the mitochoudria as well as a criss-crass net work of mem-branous strusture, which may be a part of the nuclear materials but lack of chromatin or deriv-ed from the unique invaginations of nuclear membrane, fill up the cytoplasmic central part of the cell.The earliest stage we found in the testis of E. collarum is the late spermatocyte, which contains a large nucleus with irregular chromatin paiches, scattered mitochondria and Golgi apparatus.The early spermatids are irregular spheroicl and interconnected by cytoplasmic bridges. The compact nucleus starts to split from one end, and gradually forms a thick ring along the equator of the cell, while the chromatin becomes very fine sand-like grain.The mid spermatid gradually flattenecl, and the nucleus becomes a complcte ring with fine odd pieces of threacls like chromatin, which then arranged into 4-5 longitudinal bands. Mitochondria and the cytoplasmic bridges between cells are still present. Besides, there are a number of curious tubular structures appeared by invagination of the nuclear membrane, and chen probably extending and branching in accompany with the development of the spermatid, forming the membranous structure in the matutc spermatozoon or disappeared during the later stages.The chromatin in the nucleus of the late spermatid is assemblcd into a rough band and then to form a homogenous dark nucleus. The excess nuclear materials are eliminated by brea-king away from the spermatid one pice after another and each of them form a cyst like re- sidual body, which is arranged in a row between every two spermatids.