Absence de corrélation génotype-phénotype dans les absences de canaux déférents

Absence of the vas deferens is a rare cause of male infertility, associated with mutations in the cystic fibrosis transmembrane regulator (CFTR) gene in about 80% of cases. Only limited published data are available concerning the correlation between genotype and reproductive tract abnormalities observed in this disease: presence or absence of seminal vesicles and parts of the epididymis, symmetrical or asymmetrical lesions, testicular volumes. We screened 47 patients for the 13 most common CFTR mutations on the cystic fibrosis gene and for the 5-thymidine variant of the polythymidine tract of intron 8. Renal, scrotal and transrectal ultrasonography was performed in each patient to explore the testes and reproductive tract. All patients presented absence of the ampullae of the vas deferens. Forty patients presented bilateral absence of the vas deferens and 7 presented unilateral absence of the vas deferens. At least one mutation of the cystic fibrosis gene was present in 64% of cases: 47% had the ΔF 508 mutation and 63% had the 5T allele. No mutation was detected in seventeen patients, including 3 patients with unilateral renal agenesis and 3 patients with unilateral absence of the vas deferens. No differences were observed for seminal vesicles and symmetry of vesicular and epididymal abnormalities between patients with or without CFTR gene mutations, but epididymal abnormalities were significantly more frequent in the group without mutation (p=0.01). Testicular volumes were significantly lower in the patients without mutation or with the 5T allele only, than in the patients with at least one CFTR gene mutation: 10.7±4.1 ml versus 15.1±4.5 ml, respectively (p<0.001). In conclusion, in cases of isolated absence of the vas deferens, there is no difference in sperm duct abnormalities between patients with or without CFTR gene mutation. These results suggest that other genetic or environmental determinants are required to explain a common pathogenesis for these malformations. The decreased testicular volume of patients without CFTR gene mutation or with the 5T allele only suggests the existence of an unidentified secretory or mixed factor involved in these forms of absence of the vas deferens.     

Expression of constitutively active Notch1 in male genital tracts results in ectopic growth and blockage of efferent ducts, epididymal hyperplasia and sterility

The Notch signaling pathway is involved in a variety of developmental processes. Here, we characterize the phenotypes developing in the reproductive organs of male transgenic (Tg) mice constitutively expressing the activated mouse Notch1 intracellular domain (Notch1(intra)) under the regulatory control of the mouse mammary tumor virus (MMTV) long terminal repeat (LTR). Tg expression was detected in testis, vas deferens and epididymis by Northern blot analysis. In situ hybridization with a Notch1-specific probe lacked sensitivity to detect expression in normal-appearing cells, but demonstrated expression in hyperplastic epithelial cells of the vas deferens, epididymis and efferent ducts. Tg males from three independent founder lines were sterile. Histological analysis of reproductive organs of young Tg males (postnatal ages 8 and 21) showed no difference compared to those of non-Tg males. In contrast, in adult Tg mice from day 38 onwards, the efferent ducts, the vas deferens and most epididymal segments revealed bilateral epithelial cell hyperplasia with absence of fully differentiated epithelial cells. Electron microscopy confirmed the uniformly undifferentiated state of these cells. Immunohistochemistry with anti-PCNA antibody also revealed enhanced proliferation of Tg epididymis. In adult Tg testis, the different generations of germ cells of seminiferous tubules appeared normal, although some tubules were highly dilated and revealed an absence of early and/or late spermatids. The epithelial cells of the Tg tubuli recti and rete testis were not abnormal, but the rete testis was highly dilated and contained numerous spermatozoa, suggesting a downstream blockage. Consistent with a blockage of efferent ducts often seen at the rete testis/efferent duct interface, spermatozoa were absent in epididymis of all adult Tg mice and in all highly hyperplastic efferent duct tubules of these Tg mice. Such a blockage was visualized by injection of Evans blue dye into the rete testis lumen. Finally, the presence of ectopic hyperplastic efferent duct tubules was observed within the testicular parenchyma itself, outside their normal territory, suggesting that Notch1 signaling is involved in the establishment of these borders. This phenotype seems to represent a novel developmental defect in mammals. Together, these results show that constitutive Notch1 signaling significantly affects the development of male reproductive organs.     

Selective partitioning of plasma membrane antigens during mouse spermatogenesis

The selective partitioning of cell membrane components during mouse spermatogenesis has been examined using a heterologous antibody raised against isolated type B spermatogonia. The anti-type B spermatogonia rabbit IgG (ATBS) binds to isolated populations of mouse primitive type A spermatogonia, type A spermatogonia, type B spermatogonia, preleptotene spermatocytes, leptotene/zygotene spermatocytes, pachytene spermatocytes, round spermatids, residual bodies, and mature spermatozoa. Although immunofluorescent labeling is uniformly distributed on the cell surface of early spermatogenic cells, a discrete topographical localization of IgG is observed on testicular, epididymal, and vas deferens spermatozoa. The convex surface of the acrosome, postacrosomal region, and tail are labeled. Antibody does not bind to a broad area corresponding to the concave region of the acrosome. The antibody also binds to mouse somatic cells including Sertoli cells, Leydig cells, thymocytes, and splenocytes, but not to mature spermatozoa of the vole, rat, hamster, guinea pig, rabbit, or human. ATBS, after absorption with mouse splenocytes or thymocytes, does not react with any somatic cells examined by fluorescence except with Sertoli cells. In addition, all reactivity with testicular, epididymal, and was deferens spermatozoa is abolished. However, spermatogenic cells at earlier stages of differentiation, including residual bodies, still react strongly with the absorbed antibody. The number of surface receptor sites per cell for absorbed ATBS ranges from approximately 3 million on primitive type A spermatogonia to 1 million on round spermatids and on residual bodies. Spermatozoa, however, have only 0.003 million binding sites for absorbed ATBS, in contrast to 10 million sites for the unabsorbed antibody. It appears that receptor sites for absorbed ATBS are not masked by components of epididymal secretions. These data imply, therefore, that specific mechanisms operate at the level of the cell membrane during spermiogenesis to insure that some surface components, not required in the mature spermatozoon, are removed selectively by partitioning to that portion of the spermatid membrane destined for the residual body.     

东方扁虾雄性生殖系统的解剖学和组织学研究

东方扁虾雄性生殖系统由精巢、输精管及雄性生殖孔三部分组成,输精管可分为前、中、后三段。精巢由卷绕的前、后收集管及持靠其上的许多生精腺囊所组成。同一腺囊内的精细胞发生基本同步,而不同腺囊内则可以不同步。收集管的主要功能是将精细胞团输送至输精管。精荚在输粗管内运行时一直进行着精子的形成过程,直至精子成熟。位于输精管末段不肌层外的索带状细胞团被认为是造雄腺。     

Flow cytometric analysis of rodent epididymal spermatozoal chromatin condensation and loss of free sulfhydryl groups

Flow cytometric measurements were made on acridine orange (AO) and 7-diethylamino-3-(4'-maleimidylphenyl)-4-methyl-coumarin (CPM)-stained epididymal- and vas deferens-derived spermatozoal nuclei to follow the course of chromatin condensation and oxidation of free sulfhydryl groups, respectively, during passage through mouse and rat posttesticular reproductive tracts. Alterations of mouse and rat spermatozoal chromatin during transition from a testicular elongated spermatids to epididymal caput spermatozoa resulted in a threefold loss of DNA stainability with AO. Passage of spermatozoa from the caput to corpus epididymis was accompanied by an approximate 15% loss of DNA stainability, which was maintained at that level throughout passage into the vas deferens. AO stainability of epididymal spermatozoal nuclei was generally independent of -SH group stainability. CPM stainability of rat spermatozoal nuclei free -SH groups was 83%, 18%, and 11% of caput spermatozoal values for corpus, cauda epididymis, and vas deferens, respectively. Comparable values for mice were 69%, 20%, and 18%. CPM stainability was relatively homogeneous for these mouse and rat reproductive tract regions, except mouse corpus epididymis spermatozoal nuclei stained very heterogeneously. Rat spermatozoa detained by ligature up to 7 days in the caput, corpus, and cauda epididymi had CPM staining values equal to or below those of normal vas spermatozoa, indicating that disulfide (S-S) bonding is intrinsic to the spermatozoa and is independent of the epididymal environment. These data suggest that chromatin condensation and loss of spermatozoal DNA stainability during passage from the testis to the vas deferens are independent of S-S bonding.(ABSTRACT TRUNCATED AT 250 WORDS)     

The histochemical localization of prostaglandin synthetase activity in reproductive tract of the male rat.

PG synthetase activity was assessed histochemically in the reproductive tract of male rats. Moderate activity was observed in tails of spermatozoa within the corpus and cauda epididymidis but there was no activity in the caput epididymidis or the seminiferous tubules. The sperm tail activity was maximal for cells within the vas deferens. PG synthetase activity was also observed in individual adipose cells adhering to the testicular capsule, epididymis and vas deferens, and in isolated interstitial cells of the testis and the caput, corpus and cauda epididymidis. Specific cells in the capsules of the testes, epididymis and vas deferens also produced PGs. The activity observed in the interstitial cells of the testis and the caput epididymidis was less than that for the other tissues in terms of the proportion of possible cells. The demonstration of PG synthetase activity paralleled to known loss of arachidonic acid from the phospholipids of the spermatozoa as they pass through the male tract. Endogenous substrate was not limiting in the assay system, even in the testis and caput epididymidis where PG synthesis was not normally observed, indicating that a PG synthesis inhibitor may be present in these two tissues. PG synthetase activity within teased seminiferous tubules was markedly increased by physical trauma. Indomethacin diminished but did not eliminate synthesis.     

武汉地区克氏原螯虾繁殖期的研究

为探究武汉地区克氏原螯虾(Procambarus clarkii)繁殖期的问题,采用石蜡切片的方法,对武汉地区自然群体中克氏原螯虾雌雄成体的生殖腺进行了周年观察研究。结果表明,武汉地区成年克氏原螯虾的卵母细胞发育不同步,在4~5月以及9~10月的卵巢中都有大量成熟期的卵子,同时也含有少量卵黄发生前期或初期的卵母细胞。6~7月和11月都可见产后恢复期的卵巢,内含少量未产出的正在退化的过熟卵和一些卵黄发生前期或初期的卵母细胞。精巢发育的年周期变化没有卵巢变化的那么明显,但也可以看到,在4~6月和9~10月,含精子细胞和精子的精小管的比例大大增加,而在其他时期,含精原细胞和精母细胞的精小管比例较多。这些结果提示,武汉地区克氏原螯虾一年有两个繁殖高峰期,一个在4~5月,另一个在9~10月。     

Immunohistochemical localization of carbonic anhydrase isoenzymes in the human male reproductive tract

The distribution of human carbonic anhydrase (HCA) isoenzymes I, II and VI in the human male reproductive tract was studied using specific antisera against affinity purified isoenzymes in conjunction with the peroxidase-antiperoxidase complex method. HCA VI-specific staining could not be demonstrated in any of the tissues studied, and HCA I was observed only in red blood cells. Immunostaining denoted HCA II in the epithelia of the seminal vesicle, ampulla of the ductus deferens and distal ductus deferens. Some cells in the epithelium of the corpus and cauda epididymidis also stained for HCA II. The staining for HCA II in the epithelium of the reproductive tract declined from the strongly positive seminal vesicle to the proximal part of the ductus deferens, which stained negatively. There were also HCA II-positive particles derived from the apical protrusions of the epithelium in the lumina of the seminal vesicle, ampulla of the ductus deferens and ductus deferens. The physiological role of HCA II is linked to the secretion of bicarbonate into the seminal plasma and thereby to the regulation of sperm motility and pH in the seminal plasma.     

Species-specific expression of microsomal prostaglandin E synthase-1 and cyclooxygenases in male monkey reproductive organs

We investigated the tissue distribution and cellular localization of microsomal PGE synthase-1 (mPGES-1) and cyclooxygenase (COX)-1 and -2 in male monkey reproductive organs. Western blotting revealed that monkey mPGES-1 was expressed most intensely in the seminal vesicles, moderately in the testis, and weakly in the epididymis and vas deferens. The tissue distribution profile was quite different from those profiles for rats, rabbits, and pigs, e.g., rat mPGES-1 was the most abundant in the vas deferens, and the rabbit and pig enzymes, in the testis. Immunohistochemical staining with mouse monoclonal anti-human mPGES-1 antibody revealed that monkey mPGES-1 was localized in spermatogonia, Sertoli cells, and primary spermatocytes of testis and in epithelial cells of the epididymis, vas deferens, and seminal vesicles. In monkeys, COX-1 was localized in epithelial cells of the epididymis and vas deferens, whereas COX-2 was dominantly found in epithelial cells of the seminal vesicles.     

Male reproductive system of the arrow crab Stenorhynchus seticornis (Inachoididae)

Our aim was to describe the reproductive system of males and the formation of sperm packages in the seminal receptacle (SR) of recently mated females of the arrow crab Stenorhynchus seticornis. The male reproductive system was analyzed, and was described using light microscopy and histological and histochemical methods. The first pair of gonopods was described by means of scanning electron microscopy. Additionally, the dehiscence of spermatophores was tested using samples obtained from the vas deferens of males and from the seminal receptacle of recently mated females. Testes were tubular type, and each vas deferens consisted of three regions: the anterior vas deferens (AVD), including a proximal portion that was filled with free spermatozoa and a distal portion contained developing spermatophores; the median vas deferens (MVD) that contained completely formed spermatophores; and the posterior vas deferens (PVD), which contained only granular secretions. The accessory gland, which was filled with secretions, was located in the transition region between the MVD and the PVD. The spermatophores from the MVD were of different sizes, and none of them showed dehiscence in seawater, whereas those spermatophores in contact with the seminal receptacle were immediately broken. The ultrastructure of the gonopods revealed the presence of denticles at the distal portion, which contribute to the mechanical rupture of the spermatophore wall during the transfer of sperm. The contents of the PVD and accessory gland of males are transferred together with the spermatophores, and are responsible for the secretions observed among the sperm packets in the SR of the female. We suggest that these secretions formed the layers found in the SR of recently mated females, and may play a role in sperm competition in arrow crabs.     

Immunohistochemical localization of carbonic anhydrase isoenzymes in the human male reproductive tract

Summary The distribution of human carbonic anhydrase (HCA) isoenzymes I, II and VI in the human male reproductive tract was studied using specific antisera against affinity purified isoenzymes in conjunction with the peroxidase-antiperoxidase complex method. HCA VI-specific staining could not be demonstrated in any of the tissues studied, and HCA I was observed only in red blood cells. Immunostaining denoted HCA II in the epithelia of the seminal vescle, ampulla of the ductus deferens and distal ductus deferens. Some cells in the epithelium of the corpus and cauda epididymidis also stained for HCA II. The staining for HCA II in the epithelium of the reproductive tract declined from the strongly positive seminal vesicle to the proximal part of the ductus deferens, which stained negatively. There were also HCA II-positive particles derived from the apical protrusions of the epithelium in the lumina of the seminal vesicle, ampulla of the ductus deferens and ductus deferens. The physiological role of HCA II is linked to the secretion of bicarbonate into the seminal plasma and thereby to the regulation of sperm motility and pH in the seminal plasma.     

Studies of the male reproductive system of the amphipod Orchestia platensis Kr?yer (Crustacea: Amphipoda)

Morphological details of the testis, seminal vesicles and vas deferens of Orchestia platensis are described. The follicular lumen of the mature testis contains spermatogonia, spermatocytes, spermatids and spermatozoa. The histochemical nature of the testis and the vas deferens is elucidated. The spermatozoa and vas deferens contain acid sulphated mucopolysaccharides and neutral mucopolysaccharides. In addition, they contain basic proteins, disulphide groups, lipids, phospholipids, RNA and DNA.     

Histological and immunocytochemical study of deferens ducts in the Chinese rat snake (Zaocys dhumnades)

To investigate the relationship between structure and function of the deferens ducts in the Chinese rat snake (Zaocys dhumnades), morphological changes within an annual cycle were observed by routine histological techniques. Also, the correlation of androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR) and aromatase (Ar) expressions in the vas deferens and testis were studied immunohistochemically. To confirm that the sperm and the spherical structure existed in deferens ducts, we also used routine histological technique observed deferens ducts in the Striped-tailed rat-snake (Elaphe taeniura), Red-banded snake (Dinodon rufozonatum), and Tiger-spotted neck-troughed snake (Rhabdophis tigrina lateralis). The results showed that the deferens ducts of the Chinese Rat Snake were composed of efferent duct, epididymal duct and vas deferens. Efferent duct contained sperm from August-October, and the sperm were observed in the epididymal duct from August-the following January. Throughout the year (except July) a large number of sperm were present in the vas deferens where a previously unreported spherical structure formed by spermatids was observed, which showed no significant differences in the IOD values of AR-, ER-, PR- and Ar-immunoreactivities. Since the spermatids in the spherical structure were undergoing spermatogenesis and this phenomenon also existed in the Striped-tailed rat-snake and Red-banded snake, the term, seminiferous spherule, was named for this spherical structure This study demonstrated that the testis was the main site for snake spermiogenesis, and the seminiferous spherule in vas deferens was the other Both the epididymis and vas deferens stored sperm; however, the vas deferens was the main organ for sperm storage.     

SERPINE2, a serine protease inhibitor extensively expressed in adult male mouse reproductive tissues, may serve as a murine sperm decapacitation factor

SERPINE2, one of the potent serine protease inhibitors that modulates the activity of plasminogen activator and thrombin, is implicated in many biological processes. In the present study, we purified SERPINE2 from mouse seminal vesicle secretion (SVS), using liquid chromatography and identified it by liquid chromatography/tandem mass spectrometry, and it showed potent inhibitory activity against the urokinase-type plasminogen activator. SERPINE2 was expressed predominantly in seminal vesicles among murine male reproductive tissues. It was immunolocalized to the SVS and mucosal epithelium of the seminal vesicle, epididymis, coagulating gland, and vas deferens. In the testes, SERPINE2 was immunostained in spermatogonia, spermatocytes, spermatids, Leydig cells, and spermatozoa. SERPINE2 was also detected on the acrosomal cap of testicular and epididymal sperm and was suggested to be an intrinsic sperm surface protein. The purified SERPINE2 protein could bind to epididymal sperm. A prominent amount of SERPINE2 was detected on ejaculated and oviductal spermatozoa. Nevertheless, SERPINE2 was detected predominantly on uncapacitated sperm, indicating that SERPINE2 is lost before initiation of the capacitation process. Moreover, SERPINE2 could inhibit in vitro bovine serum albumin-induced sperm capacitation and prevent sperm binding to the egg, thus blocking fertilization. It acts through preventing cholesterol efflux, one of the initiation events of capacitation, from the sperm. These findings suggest that the SERPINE2 protein may play a role as a sperm decapacitation factor.     

Histochemical evaluation of glycoconjugates in the male reproductive tract with lectin-horseradish peroxidase conjugates: II. Staining of ciliated cells, basal cells, flask cells, and clear cells in the mouse

Efferent reproductive ducts of male mice, including ductuli efferentes, epididymis, and vas deferens, were fixed and embedded in paraffin, and sections were stained with a battery of lectin-horseradish peroxidase conjugates to localize specific sugars or sugar sequences in glycoconjugates. Cilia and the apical surfaces of ciliated cells in the ductuli efferentes stained intensely with lectin specific for sialic acid and terminal alpha-N-acetyl-D-galactosamine. Flask cells and clear cells in the epididymis reacted positively and similarly with most lectins used, providing evidence that these cell types are related. In contrast, disparities in lectin staining suggest that flask cells and clear cells are a cell type distinct from principal cells. Basal cells were not present in the ductuli efferentes but formed a continuous layer in the epididymis and vas deferens. Basal cells contained oligosaccharides terminated by sialic acid and alpha-D-galactose and varying amounts of terminal beta-D-galactose and alpha-N-acetyl-D-galactosamine. Basal cells also stained variably with lectins specific for the core region of complex type N-glycosidic side chains. The basal cells varied structurally, having long spinous apical processes approaching or reaching the lumen in region I of the epididymis and being low cuboidal or squamoid and lacking apical processes in epididymal regions II-V and in the vas deferens. The contiguous nature of the basal cells and the presence of glycoconjugates bearing terminal alpha-galactosyl residues in all basal cells suggest a possible role for these cells in a regulatory influence on transepithelial movement of fluid and/or ions in the epididymis and vas deferens.     

Cyclic changes in the testis of the brook stickleback Eucalia inconstans (Kirtland)

The cyclic changes in the testis of the five-spined stickleback Eucalia inconstans (Kirtland) were studied histologically. Specimens were trapped between July 1965 and July 1967 in a shallow pond near London, Ontario. A three-dimensional microscopic study showed a main vas deferens and a system of primary, secondary and tertiary tubules. The testis cycle was divided into seven arbitrary stages. Spawning takes place from mid-April to mid-July. This is followed by the division of primary spermatogonia which are located along the walls of the tubules, producing cysts of spermatogonia enclosed in connective tissue which is surrounded by a thin epithelium. Both primary and secondary spermatocytes develop within these cysts. Breakdown of the cysts occurs with the development of spermatids and spermiogenesis occurs while spermatids are free in the tubules. Over-wintering of mature sperm takes place. Development of mature sperm from primary spermatogonia takes about 156 days. Germinal epithelium is absent but primary germ cells are believed to be those cells occupying the spaces between the tubules of the testis. No tissue which might be implicated in hormone production was observed. Phagocytic invasion of the testis has been studied. Massive infiltration by phagocytes is believed to be responsible for the sudden increase in testis weight observed during spawning. These cells ingest sperm nuclei and groups of them have been observed in the lumen of the tubules and the vas deferens, probably on their way out of the body.     

Spermatogenesis and spermatophore production in the hawaiian red lobster Enoplometopus occidentalis (Randall) (Crustacea,nephropidae)

Light microscopy of the male reproductive tract of the Hawaiian red lobster Enoplometopus occidentalis documented the cyclic nature of spermatogenesis and spermatophore formation. Testes are composed of a convoluted collecting tubule bearing many spermatogenic follicles, all within a supporting mesentery. Spermatogonia are restricted to the basal side of the follicular epithelium and proliferate at onset of spermateleosis within the same follicle. Two generations of spermatogenic cells thus occupy each follicle, and accessory cells in the follicle form a basophilic epithelium between them. These accessory cells may detach with the spermatozoa at spermiation. The vas deferens lies outside the testicular mesentery and consists of a coiled proximal portion in which spermatophore production commences. Clusters of spermatozoa are here surrounded by a PAS-positive primary spermatophore layer, and a PAS-negative outer bounding layer is initiated. Completed further distally in the vas deferens, the outer bounding layer is thinner on the side of the spermatophore which adheres to the substratum after ejaculation; the thick side of this layer forms a broad cap. Outer circular and inner longitudinal muscular layers become well developed in the distal loop and descending portions of the vas deferens. The terminal portion of this duct contains no spermatophore prior to ejaculation. It has a longitudinally folded epithelium and an attached tubular gland which produces an extra-spermatophoral, gelatinous secretion. The androgenic gland is associated with this terminal segment of the vas deferens. These features are compared with those reported for other lobsters.