共查询到5条相似文献,搜索用时 0 毫秒
1.
A. R. Jones Denise Stevenson Primrose Hutton A. G. Dawson 《Cellular and molecular life sciences : CMLS》1981,37(4):340-341
Summary The male antifertility agent -chlorohydrin (I) is metabolized by rat and boar sperm to -chloroactaldehyde (III), -chlorolactate (IV) and Cl– and not to the proposed active metabolite, -chlorohydrin-1-phosphate (III). It is proposed that -chlorolactaldehyde is produced intracellularly by a specific enzyme and that this is the metabolite responsible for the species-specific antifertility activity of -chlorohydrin.This work was supported by The National Health and Medical Research Council of Australia. 相似文献
2.
Gvakharia BO Bebas P Cymborowski B Giebultowicz JM 《Cellular and molecular life sciences : CMLS》2003,60(8):1744-1751
Release of sperm bundles from moth testes is controlled by the local circadian oscillator. The mechanism which restricts migration of sperm bundles to a few hours each day is not understood. We demonstrate that a daily cycle of sperm release is initiated by the migration of folded apyrene sperm bundles through a cellular barrier at the testis base. These bundles have conspicuous concentrations of actin filaments at their proximal end. Inhibition of actin polymerization by cytochalasin at a specific time of day inhibited sperm release from the testis. Likewise, application of double-stranded actin RNA specifically inhibited sperm release. This RNA-mediated interference (RNAi) lowered the pool of actin mRNA in tissues involved in sperm release. The decline in mRNA levels resulted in the selective depletion of F-actin from the tip of apyrene sperm bundles, suggesting that this actin may be involved in the initiation of sperm release. Combined results of RNAi experiments at physiological, cellular and molecular levels identified unique cells that are critically involved in the mechanism of sperm release.Received 11 April 2003; received after revision 2 May 2003; accepted 27 May 2003 相似文献
3.
C. Bressac D. Joly J. Devaux D. Lachaise 《Cellular and molecular life sciences : CMLS》1991,47(1):111-114
Summary In order to test the validity of the prediction of the mating pattern of females from the sperm length distribution in males, three species ofDrosophila were analysed. Males in the three species are equally polygynous but females differ in the level of polyandry. A low recurrence polyandry is observed in the sperm dimorphic speciesD. affinis while a high recurrence polyandry is observed in the sperm monomorphic speciesD. latifasciaeformis andD. littoralis. These results are consistent with the hypothesis proposed previously that sperm dimorphism in males can only be maintained by a selective alternative in females (i.e. facultative female polygamy), whereas a stricter mating system (e.g., obligatory polyandry) should only result in sperm monomorphism irrespective of the absolute value of sperm length. 相似文献
4.
Diekman AB 《Cellular and molecular life sciences : CMLS》2003,60(2):298-308
Glycoconjugates in the mammalian reproductive tract are critical components of the molecular mechanisms that control sperm
maturation, sperm transport and gamete interactions. In the oviduct of many species, sperm transport and maturation are regulated
by protein-carbohydrate interactions that form a sperm reservoir. Subsequently, gamete interactions are mediated by the binding
of lectin-like sperm proteins with carbohydrate moieties on the zona pellucida. The sperm glycocalyx is extensively modified
during sperm transport and maturation. Multiple functions have been proposed for this dense carbohydrate layer overlying the
sperm plasmalemma, and sperm-surface carbohydrates have been implicated in immune-mediated human infertility. The structure
and function of glycoconjugates in the oviductal sperm reservoir, the zona pellucida, and on the sperm surface are reviewed. 相似文献
5.
Yue Zhao Hua Diao Zimei Ni Shuanggang Hu Heguo Yu Yonglian Zhang 《Cellular and molecular life sciences : CMLS》2011,68(4):697-708
Spermatozoa acquire forward motility and fertilizing capacity during their transit through the epididymis. The maturation
process involves modifications of the sperm surface by different proteins that are secreted by a series of specialized regions
in the epididymal epithelium. Here we show that the rat epididymis-specific β-defensin 15 (Defb15) exhibits an androgen-dependent expression pattern, and it can bind to the acrosomal region of caput sperm. Coculture of
caput spermatozoa with Defb15 antibody in vitro resulted in a significant decline in sperm motility. Moreover, the total and
progressive motility of the spermatozoa dramatically decreased in rats when Defb15 was downregulated by lentivirus-mediated RNAi in vivo. Remarkably, knock down of Defb15 led to a reduction in fertility and embryonic development failure. In addition, the recombinant Defb15 showed antimicrobial
activity in a dose-dependent fashion. These results suggest that Defb15 plays a dual role in both sperm maturation and pathogen
defense in rat epididymis. 相似文献