柄海鞘生殖系统的组织学研究

Histology of Reproductive System of Styela clava(Urochordata:Ascidiacea)

1998年 5月至 1999年 4月每月 1次取材研究了柄海鞘的生殖系统的组织学、发育及季节变化 .柄海鞘为雌雄同体的尾索动物 ,其卵巢和精巢相间排列 ,但不同期发育 .精巢由外膜和无数生精小管组成 .外膜由单层扁平上皮和薄层肌肉构成并向腺体内延伸参与形成生殖小管的基膜 ,生殖上皮位于基膜上 ,它不断的向腔内分裂增殖出精原细胞、初级精母细胞、次级精母细胞、精细胞和精子 .精原细胞较大 ,圆形或卵圆形 ,核较大 ,与细胞同型 ,染色质呈颗粒状散布于核质中 ,核仁 1个 ,明显 .初级精母细胞结构相近 ,但逐渐变小 .精细胞圆形 ,核不规则 ,着色深 .精子呈短杆状 ,悬浮于生殖小管或输精小管腔中 .输精小管壁由单层立方上皮组成 ,细胞的腔面端具微绒毛 .卵巢由外膜及生殖小区构成 .外膜由单层扁平上皮及薄层肌肉构成并向腺体内延伸将卵巢分成许多生殖小区 ,生殖上皮位于生殖小区中心区 ,它不断地向周围放射状增殖出卵原细胞 ,故称之为生发带 .它不断地分裂为卵母细胞和卵细胞 .卵原细胞较小 ,圆形 ,核较小 ,圆形或卵圆形 ,染色质分散为颗粒状位于核质中 .卵母细胞体积不断增大 ,完成卵黄的积累后形成成熟的卵细胞 .生殖小区间充满结缔组织 ,其中含有血窦、神经和输卵小管 ,其管壁为单层立方上皮 。

From May 1998 to April 1999, we studied monthly on histology of male reproductiv e system of Styela clava.The Styela clavais hermaphroditism Urochordata animals and the ovary alternate with testis on the inner side of mantle.The tes tis consists of outer membrane and great number of branchy seminiferous tubules. Outer membrane, is composed of simple squamous epithelium and thin layer muscles , extend into testis and become the basement membrane of seminiferous tubules.Th e tubule showed by the transverse section is made up of germinative epithelia (s permatogonium), and the germinative epithelia constantly produce spermatocyte, s permatid and sperm.The ovary consists of thin ovary wall and germinative zone.Th e wall extend into ovary and divides it into many small part, and the gerninativ e zone produce oogonium and oocyte, and the oocyte matured by vitellogenesis.The re is connective tissues among the gerninative zone,and many blood sinusoid,ne rves and oviduct disperse in the connective tissue.The wall of oviduct is compos ed of a simple cuboidal epithelium, thin layer muscles.