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双壳类软体动物精子发生及其在系统演化研究中的应用前景 总被引:11,自引:0,他引:11
综述了双壳类软体动物精子发生及精子形态结构方面的研究进展,指出双壳类软体动物精子发生过程中精细胞分化具有种、属特异性,精细胞分化的细节是区别个体外部形态很近的物种的依据;精子的形态结构具有种的特征,精子结构的比较研究将成为双壳类软体动物系统演化研究的重要方法之一。 相似文献
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本文了报道了在非繁殖季节,17α-MT可诱发淡水雄鲻鱼精于发生和释精.与海水鲻鱼相比较,淡水雄鲻服药后4周才出现释精,而生活在海水的鲻鱼约2周,且释精强度淡水鲻鱼比海水差。文中讨论了它们之间不同的原因。这一结果首次证实,生活在淡水的雄鲻可用激素处理,诱发其发育和成熟,并有可能应用于人工繁殖。 相似文献
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本文首次报道了17α-甲基睾酮(17α-methyltestosterone,17αMT)可激发文昌鱼精子发生。研究结果表明,低和高剂量(24μg/L和48μg/L)17α-甲基睾酮可促使精巢直径为0.60mm文昌鱼精巢中的初级精母细胞发育为精细胞和精子。值得指出的是,高剂量17αMT促进生精效果最佳。低剂量17αMT对精巢直径0.90mm文昌鱼的精子的形成没有影响,而高剂量则可促进精子形成。这些结果表明,文昌鱼精子发生象脊椎动物一样,受雄激素的调控。 相似文献
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为了解糙海参(Holothuria scabra)精子发生的过程及其形态结构,作者于2013年11月~2014年4月每月采集2头海南岛的野生雄性糙海参,取精巢组织固定后分别制作投射电镜、扫描电镜切片和石蜡包埋切片,在电镜和光镜下连续观察。观察结果表明,糙海参精子发生经历了精原细胞、初级精母细胞、次级精母细胞、精细胞和成熟精子5个阶段。精细胞分化过程可分为3个时期,早期:细胞核前端出现前顶体囊;中期:顶体腔内出现围顶体物质;后期:胞质往尾部方向收缩,形成精子中部。糙海参成熟精子全长约60μm,由头部、中部和尾部3部分组成,为典型的鞭毛型精子。精子头部呈球形,精子核中顶体形态为"U"型内陷囊状体,围顶体物质呈"月牙"形,核染色质凝集成团块状。精子中部由一个巨大的线粒体和中心粒复合体融合而成。精子尾部鞭毛横切面为典型的"9+2"微管结构。本研究可为糙海参的繁殖生物学和人工育苗提供理论参考。 相似文献
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Horiguchi T Kojima M Takiguchi N Kaya M Shiraishi H Morita M 《Marine pollution bulletin》2005,51(8-12):817-822
Histological examination of gonads as well as chemical analysis of organotin compounds in tissues of the giant abalone, Haliotis madaka, was conducted to evaluate continuing endocrine disruption in abalone populations in Japan. Abalone specimens were collected from two different areas, Tsushima as a reference site and Jogashima as a site representative of declining abalone populations where serious organotin contamination had been observed, each month from January 1998 to March 1999. Scores were given to the development stages of reproductive cells in the ovary and testis. The degree of sexual maturation was evaluated by calculating the mean value of a histogram of these scores for the reproductive cells of each abalone. The temporal variations in degree of sexual maturation showed that female and male abalone from Tsushima matured synchronously, while those from Jogashima did not, which were similar to results of the previous study during September 1995–November 1996. Approximately 19% of the female abalone from Jogashima were masculinized with an ovo-testis, which was also similar to the result of the previous study. The masculinization of female abalone is reported to be induced by tributyltin (TBT) and triphenyltin (TPhT) from antifouling paints. Concentrations of the sum of butyltins (TBT, dibutyltin (DBT) and monobutyltin (MBT): ΣBTs) and the sum of phenyltins (TPhT, diphenyltin (DPhT) and monophenyltin (MPhT): ΣPhTs) in the muscle of abalone from Jogashima (n = 73) of 7.8 ± 9.0 ng/g wet wt. and 4.5 ± 6.8 ng/g wet wt., respectively, were significantly higher than those from Tsushima (n = 87) of 4.7 ± 4.9 ng/g wet wt. and 0.8 ± 1.7 ng/g wet wt., respectively (p < 0.05 for ΣBTs; p < 0.001 for ΣPhTs), although concentrations of TBT and TPhT in the muscle of abalone from Jogashima (n = 73) of 2.2 ± 2.5 ng/g wet wt. and 5.8 ± 5.1 ng/g wet wt., respectively, were insignificantly and significantly higher than those from Tsushima (n = 87) of 0.4 ± 0.6 ng/g wet wt. and 0.5 ± 0.9 ng/g wet wt., respectively, (p > 0.05 for TBT; p < 0.001 for TPhT). Thus, endocrine disruption as well as contamination by organotins in the giant abalone from Jogashima is still persisting. 相似文献
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Information on the reproductive development of species of box jellyfish (class Cubozoa) is poor globally, despite their significance as potent stingers and worrying projections about range expansions. While most species are confined to tropical and subtropical waters, the South African box jellyfish Carybdea branchi is commonly found in the cold-water (especially southern) Benguela ecosystem. Its biology is unknown. Here, we examine reproductive development and describe gametogenesis in this dioecious species. Four and five maturity classes were determined for males and females, respectively, as well as five oocyte developmental stages. Oocyte sizes differed significantly between developmental stages. Mature and immature medusae differed significantly in size, but males and females did not. Individuals matured at approximately 30 mm average bell dimensions. Carybdea branchi displayed gonadal development characteristic of a semelparous organism. 相似文献
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半滑舌鳎精子发生的组织学研究 总被引:6,自引:1,他引:5
本文应用组织学方法对半滑舌鳎雄鱼精巢结构和精子发生过程进行了详细地研究.观察结果表明,它的精巢结构特点是随着精巢的发育可见它的精巢外面有一条管状贮精囊与输出管相连,在精巢发育成熟过程中,贮精囊中逐渐充满精子,这个特点有助于了解半滑舌鳎的受精生物学的复杂性.另外,从半滑舌鳎精子发生过程分析,它的精巢属于小叶型,精巢发育分为6期.精子发生经历精原细胞、精母细胞、精子细胞及精子.最后,文中还讨论了半滑舌鳎精巢中非生殖细胞(间质细胞和Sertoli细胞)的分布及其可能的生理作用. 相似文献