Ultrastructure of spermatogenesis and spermiogenesis in the half-smooth tongue sole Cynoglossus semilaevis
KANG Xian-Jiang 1,LIANG Chun-Guang1,GUO Ming-Shen1,GE Shao-Qin1,MU Shu-Mei1,SU Wen-Qing2,LIU Xue-Hui3 1.College of Life Sciences,Hebei University,Baoding 071002,Hebei,China2.Tangshan Fishery Technical Extension Center,Tangshan 063004,Hebei,China3.Huida Aquiculture Co.,Ltd,Luannan 063509,Hebei,China
The ultrastructure of spermatogenesis and spermiogenesis in the half-smooth tongue sole Cynoglossus semilaevis was studied by transmission electron microscopy.The testes are of the lobular type.Five stages,of spermatogenesis were identified;primary spermatogonia,secondary spermatogonia,primary spermatocytes,secondary spermatocytes and spermatids.During zygotene,prophaseⅠ,paired homologous chromosomes began to form synaptonemal complexes.The synaptonemal complexes were fully formed at pachytene and dissolved afterward.The synaptonemal complex served as a means of ensuring genetic recombination between two homologous chromosomes.Spermatids differentiated into sperms via the process of spermiogenesis,which included three stages:nuclear condensation,migration of mitochondria and axoneme growth.During condensation of the nucleus,chromatin,surrounding the implantation fossa condensed to form rough particles.The remaining chromatin,located in the other parts of the nucleus,began to concentrate later.Subsequently,,these rough particles condensed into even material,of high electron density.At the same time,the gap between the two layers of nuclear membranes enlarged gradually and aperinuclear space was formed.Uncondensed material was discharged into the perinuclear space by budding and then into the cytoplasm.During nuclear condensation,the volume and surface area of the nucleus decreased markedly.Condensation of nucleus was accompanied by axoneme growth.During the earlier stages of spermiogenesis,a pair of centrioles drew near the nucleus membrane;this caused the nuclear membrane to sag and form the implantation fossa.Chromatin surrounding the implantation fossa became condensed.Meanwhile,the distal centriole gradually started to form the axoneme.Each spermatozoan consists of a head without an acrosome,a midpiece and a long tail which contains the lateral fins and a conventional "9+2" axoneme pattern.
【Fund】： 国家自然科学基金(No.30371115);; 唐山市科技局项目(No.06125401A-1-1)资助~~
【CateGory Index】： Q954.4
【CateGory Index】： Q954.4