Ionic factors affecting motility,respiration and fertilization rate of the sperm of the bivalvePecten maximus (L.)

Fertilization of the scallopPecten maximus occurs after gametes were naturally released in sea water by the bivalve which has undergone stimulation. The motility of the spermatozoa requires their dilution in sea water (1/40). Dilution triggers an immediate increase of oxygen consumption by sperm, reflecting an activation of a cyanide-sensitive respiration of a cellular origin. When scallops were stimulated by thermal shocks or by serotonin injection, sperm sampled at the urogenital pore output duct shows a respiration-motility activation after sea water dilution which is not seen in sperm scarified from the gonad. Dilution of kidney-sampled sperm into acidic (pH 5) or Na⁺-free artificial sea water reversibly inhibits both respiration and motility. In all cases fertilization rate of sperm is correlated to the increase of respiratory rate and motility measured after dilution in different media. Whether the scallop was stimulated or not, the pH of haemolymph and pericardic fluids were one pH unit below the value of sea water, the pH of the gonad and of the kidney tissues being more acidic (6.5 in average). Our results suggest that the acidic pH of the genital tract maintains the spermatozoa in a quiescent state and that capacitation occurs when male gametes move from the gonad to the kidney from where it is naturally released.Abbreviations ASW artificial sea water - SW sea water - TRIS trishydroxymethyl-aminomethane     

SPERM DISPLACEMENT WITHOUT SPERM TRANSFER IN DROSOPHILA MELANOGASTER

In this paper we show that when Drosophila melanogaster females are mated twice, the semen of the second male causes a reduction of the effective number of resident sperm from the previous mating. This is demonstrated by two different kinds of experiments. In one set of experiments, mated females were remated to two different kinds of sterile males, one with normal semen and the other with deficient semen. The effect on the resident sperm was determined from the number of remaining progeny after mating to the sterile male, with the result that the normal semen reduced the amount of resident sperm in comparison with matings to the males with deficient semen. The second set of experiments employed interrupted matings. These experiments were based on the observation that semen is delivered before sperm during the first 5 min of copulation. The second matings were interrupted instantly, 2 min, and 4 min after the initiation of copulation. Compared to the instant interruptions, the two later interruptions had the effect of reducing the amount of resident sperm. The results of these two experiments clearly indicate that a sperm-incapacitation process plays a role in the well-documented phenomenon of sperm displacement (last-male advantage) in this species. Such a process could play a role in sperm displacement in the many cases where the mechanism is unknown.     

Correlation between spermathecal morphology and mating systems in spiders

This study tested predictions regarding male mating preferences which were based on some aspects of female reproductive morphology which may influence sperm precedence patterns in six species of spiders. Males of two species, whose 'conduit' spermathecal design has been associated in previous studies with first male sperm precedence, showed the predicted preference for associating with immature females about to moult to maturity rather than mature females. Those of a third species, however, associated indiscriminately with mature and penultimate instar females. As predicted, males of three other species with 'cul-de-sac' spermathecal morphology did not associate preferentially with immature females. Immature females were avoided in two of the species, but not in the third. One of the species with cul-de-sac spermathecae showed, as predicted, lack of a strong first male advantage in sperm precedence. These data give only limited confirmation of the predictions.     

Inhibition of Acrosomal Enzymes by Gossypol Is Related to Its Antifertility Action

ＩｎｈｉｂｉｔｉｏｎｏｆＡｃｒｏｓｏｍａｌＥｎｚｙｍｅｓｂｙＧｏｓｓｙｐｏｌＩｓＲｅｌａｔｅｄｔｏＩｔｓＡｎｔｉｆｅｒｔｉｌｉｔｙＡｃｔｉｏｎＹＵＡＮＹｕ－ｙｉｎｇ;（袁玉英）ＺＨＡＮＧＹａｎ－ｌｉｎ;（张燕林）ＳＨＩＱｉ－ｘｉａｎ（石其贤）（Ｚｈｅ...     

A Protein Extracted from Mouse Sperm That Plays an Important Role in Fertilization

ＡＰｒｏｔｅｉｎＥｘｔｒａｃｔｅｄｆｒｏｍＭｏｕｓｅＳｐｅｒｍＴｈａｔＰｌａｙｓａｎＩｍｐｏｒｔａｎｔＲｏｌｅｉｎＦｅｒｔｉｌｉｚａｔｉｏｎＺＨＵＡＮＧＤａ－ｚｈｏｎｇ;（庄大中）,ＺＨＡＮＧＴｉａｎ－ｙｉｎ（张天荫）,ＣＨＥＮＤａ－ｙｕａｎ;（陈大...     

底物膜技术检测精子顶体酶活性的研究

应用底物膜技术检测１３０例正常精液,精子顶体酶活性百分率的正常值下限为５７％。４５９例不孕症病人精液分析,无精症２５例,其余４３４例中７５％精子顶体酶活性正常。实验表明精子密度对数值与顶体酶活性百分率之间有正相关,ｒ＝０．８４（Ｐ＜０．０１）,回归方程为顶体酶活性百分率ｙ＝４８．４３％＋（８．９％）（ｌｏｇ精子计数）。活动精子百分率与顶体酶活性之间有密切正相关,ｒ＝０．９６７,（Ｐ＜０．０１）,顶体酶活性ｙ＝３８．６％＋０、３６ｘ％。前向活跃直线运动精子百分率与顶体酶活性之间也有密切相关．ｒ＝０．９６,（Ｐ＜０．０１）,顶体酶活性ｙ＝３４．２１％＋０．６１ｘ％。     

精子作载体的转基因鱼研究

本文报道了以精子为载体将美洲拟蝶抗冻蛋白基因导入罗非鱼卵,构建转基因鱼的方法,此法简单易行。斑点杂文和ＳｏｕｔｈｅｒｎＢｌｏｔ杂交结果表明,外源基因的整合率为１８．１％,与其它方法构建转基因鱼的外源基因整合率相近。     

Rat epididymis-specific sperm maturation antigens. I. Evidence that the 26 kD 4E9 antigen found on rat caudal epididymal sperm tail is derived from a protein secreted by the epididymis

Monoclonal antibody 4E9, which was raised against a partially purified detergent extract of rat caudal epididymal sperm, recognizes the tail of sperm from the cauda, but not from caput epididymidis, as well as epithelial cells in a restricted region of the distal caput/corpus epididymidis and proteins in epididymal fluid from corpus and cauda epididymidis. The antigen is apparently a glycoprotein, since it is retained on a Ricinus communis agglutinin l lectin column. Epididymal fluid antigens have apparent M_rS of 38–26 kD, whereas the memrane-associated form of the molecule has an M_r of 26 kD. Immunocytochemical data and Western immunoblot data suggest that the membrane antigen is derived from the fluid antigen, which, in turn, is secrteted by the epididymal epithelium. Characterization of the membrane antigen indicates that it is tightly associated with the sperm surface, behaving as though it is an integral membrane protein. The antigen persists on ejaculated sperm. © 1994 Wiley-Liss, Inc.     

Differential localization of two isoforms of the regulatory subunit RIIα of cAMP-dependent protein kinase in human sperm: Biochemical and cytochemical study

In the present study, immunogold labeling of ultrathin sections of ejaculated sperm was used to obtain insight into the ultrastructural localization and presumable function of type II cAMP-dependent protein kinase in sperm motion. In the flagellum, a human-specific isoform of the RIIα subunit was located on the axonemal microtubule wall, whereas a different isoform of broader specificity was present in the cytoplasm at the periphery of the coarse fibers and fibrous sheath. This isoform was also found in the mitochondria. The human-specific RIIα subunit is likely linked to microtubules by a unique binding protein of M_r 72kD. These findings are in agreement with the concept of a concerted mechanism involving phosphorylation of both the axonemal microtubules and the fibrous structures for the regulation of mammalian sperm motion. © 1994 Wiley-Liss, Inc.     

DNA fingerprint bands applied to linkage analysis with quantitative trait loci in chickens

Summary
An efficient approach to detect association between quantitative traits and bands of DNA fingerprint patterns uses intra-family tail analysis, which compares fingerprints of DNA mixes from individuals at the two tails of a phenotypic distribution. In analysis of 67 paternal half-sibs of a meat-type chicken family, of 57 sire bands generated by two probes, one sire-specific band (S6–6) was associated with abdominal fat deposition. The band effect was estimated by a linear model analysis to be 0–88 standard deviations, or about 30% of the family mean. The association between band S6–6 and abdominal fat was further examined by testing progeny of paternal half-sibs of the chickens which were used in the tail analysis, establishing genetic linkage between the DNA marker and a genetic locus affecting abdominal fat deposition.