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2.
Spider genital morphology usually provides the best characters for taxonomy. Furthermore, functional genital morphology helps to understand the evolution of complex genitalia and their role in the context of sexual selection. The genital systems of most haplogyne spider families are poorly investigated with respect to their morphology. The present study investigates the female genitalia of the oonopids Oonops pulcher, Oonopinus kilikus, and Pseudotriaeris sp. by means of light microscopy and SEM. The male palps are briefly described. Females of O. pulcher store spermatozoa in an anterior and a posterior receptaculum (PRe). The genitalia resemble the primitive dysderoid genitalia supporting the hypothesis that the subfamily Oonopinae contains more basal oonopids. In O. kilikus, the anterior receptaculum is reduced to a sclerite. Spermatozoa are stored in a PRe. The receptacula of Pseudotriaeris sp. are reduced to sclerites. Spermatozoa in the uterus internus indicate that fertilization happens there or in the ovary. The anterior sclerite might serve females to lock the uterus during copulation as suggested for other gamasomorphines. The male palp of O. kilikus is simple, whereas the palps of O. pulcher and Pseudotriaeris sp. appear more complex. Complicated structures on the palp of Pseudotriaeris sp. indicate that males exert copulatory courtship.  相似文献   

3.
    
The female genital system of the oonopid Silhouettella loricatula is astonishingly complex. The genital opening is situated medially and leads into an oval receptaculum that is heavily sclerotized except for the ventral half of the posterior wall that appears chitinized only. A large striking sclerite lying in the posterior wall of the uterus externus is attached anteriorly to the receptaculum and continues dorsally into a globular appendix that bears a furrow. The uterus externus shows a peculiar modification in its anterior wall: a paddle-like sclerite with a nail-like posterior process. This sclerite lies opposite to the furrow proceeding in the globular appendix and may serve females to lock the uterus externus by muscle contractions. Massive muscles connect the sclerite with the anterior scutum of the opisthosoma and with two other sclerites that are attached to the receptaculum and serve as attachments for further muscles. Gland cells extend around a pore field of the receptaculum. They produce secretion that encloses spermatozoa in a discrete package (secretory sac) inside the receptaculum. In this way, the mixing of sperm from different males and thus sperm competition may be severely limited or completely prevented. During a copulation in the laboratory the ejection of a secretory sac that most probably contained spermatozoa was observed, indicating sperm dumping in S. loricatula. The ejection of the secretory sac may be caused by female muscle contractions or by male pedipalp movements. The majority of the investigated females have microorganisms in the receptacula that could represent symbionts or infectious agents. The microorganisms can be identified partly as bacteria. They are enclosed in secretion and are always found in the same position inside the receptaculum.  相似文献   

4.
Sperm dumping in a haplogyne spider   总被引:1,自引:0,他引:1  
The present study shows that females of Silhouettella loricatula (Arachnida: Araneae: Oonopidae) manage to process sperm in an unusual and previously unknown way. The male ejaculate consisting of spermatozoa and globular secretion is enclosed in a secretory sac. This may avoid the mixing of sperm from different males and at least severely limit sperm competition. The process of sperm enclosure occurs within the female's sperm storage site (receptaculum) as the ejaculate is not surrounded by a sac inside the male's sperm-transferring organs (palpal bulbs). The secretion forming the sac is produced by glands adjoining the receptaculum. The possibility that globular secretions in the male palpal bulbs partly contribute to the sac cannot be ruled out completely. It is suggested that in S. loricatula , the main function of sperm enclosure in a sac is enabling females to dump the ejaculate of a male. The present study represents the first report on sperm dumping in the family Oonopidae. During five first and three second copulations in the laboratory, the dumping of a sac was observed. One dumped sac was sectioned and contained spermatozoa. Two couples were flash-fixed with liquid nitrogen early during copulation, which revealed the mechanism of the sac dumping. By muscle contractions, the receptaculum is bent backwards and the sac moved into the genital opening. The actual sac dumping occurs most probably in cooperation with the male, which moves his pedipalps rhythmically during the entire copulation. Extensions and furrows on the emboli suggest that they may additionally be used as copulatory courtship devices. The enclosure of sperm from the current male in secretion takes place during or immediately following copulation as all mated females sacrificed after copulation had a new sac containing spermatozoa in the receptaculum. Dumping sperm of a previous male during the next copulation may allow females to bias sperm precedence.  相似文献   

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Abstract. Fine morphological details of the genitalia have large potential consequences for the understanding of the reproductive biology of a particular species, especially when mating behavioral studies are difficult to conduct. Oonopidae are a highly diverse spider family comprising a variety of species with complex female reproductive systems, which may have evolved under sexual selection by cryptic female choice. The present study describes the female genitalia of five oonopid species belonging to both conventionally recognized subfamilies by means of semi‐thin sections and scanning electron microscopy. In addition, the male palps are briefly described. The organization of the female genitalia in Scaphiella hespera and Scaphiella sp. resembles the entelegyne type. A chitinized canal connects the receptaculum, where sperm are stored, with the uterus. Sperm are also present in the uterus and the canal is suggested to function as fertilization duct. The genitalia of the parthenogenetic species Triaeris stenaspis are surprisingly complex. A large sac with glands is proposed to represent the equivalent of a receptaculum in sexually reproducing females. In females of Opopaea recondita, sperm are stored in a bulge derivating from the uterus. Contractions of muscles attached to the bulge may lead to sperm dumping. The uterus can be closed by a sclerite in its anterior wall. The receptacula of females of Stenoonops reductus are joined together and contain masses of spermatozoa. Additional sperm were found in the receptacula connection suggesting that fertilization takes place there. The male palps of all the investigated species, except for S. hespera, seem to lack a distincly sclerotized sperm duct. Spermatozoa and secretions are stored in a large reservoir inside the genital bulb surrounded by glandular epithelium.  相似文献   

7.
    
Female genital structures with their allied muscles of the haplogyne spider Opopaea fosuma are described. A functional explanation of this system is given, which indicates that cryptic female choice may occur in these spiders: the anterior wall of their spermatheca is strongly sclerotized and possesses a cone-shaped hole in its upper part. A transverse sclerite that serves as muscle attachment bears a nail-like structure and lies in a chitinized area of the anterior wall of the uterus externus. Muscle contraction presses this nail into the hole of the spermatheca. In this way, the uterus externus gets both locked and fixed. Furthermore, as this occurs the copulatory orifice is enlarged and the resulting suction probably leads to previously deposited sperm being drawn from the spermatheca and dumped. This is a common mechanism used by females to influence a male's chances of fathering their offspring in a process known as cryptic female choice.  相似文献   

8.
    
DAVID PENNEY 《Palaeontology》2006,49(1):229-235
Abstract:  The spider family Oonopidae is described from Cretaceous ambers from Myanmar and Canada for the first time. Orchestina albertenis sp. nov. is the first spider to be described from Canadian Grassy Lake amber and only the second spider to be described from Canadian amber. The specimen in amber from Myanmar extends the known range of the extant genus Orchestina back another 10 million years from the previously oldest specimen in Turonian New Jersey amber. Despite being unknown as sedimentary fossils, Oonopidae occur in more fossil deposits than any other spider family and were already widespread by the Cretaceous. The family contains the oldest example of an extant spider genus along with Archaeidae, also from Burmese amber.  相似文献   

9.
Female Harpactea lepida possess a single genital opening leading into a diverticulum. This diverticulum shows no secretory layer. It continues posteriorly into a receptaculum which is associated with gland cells. In the two already described dysderids, Dysdera crocata and D. erythrina, the bilobed spermatheca lies anteriorly to the diverticulum. Gland cells are associated with the spermatheca and the diverticulum. In H. lepida, the sclerotized genital structures lie dorsally to the diverticulum and consist of a posterior and an anterior part. The posterior part shows a lamella extending laterally to sclerites functioning as muscle attachments. The anterior part has two roundish structures. A hollow stalk-like sclerite functioning as muscle attachment extends towards anterior. The posterior and the anterior part of the sclerotized genital structures fit together. A narrow uterine valve connecting the uterus externus with the diverticulum forms between them. It may be opened by muscles as also suggested for D. erythrina. In H. lepida, spermatozoa embedded in secretion are found in the diverticulum and the receptaculum. There is no evidence that they are stored under different conditions like in D. erythrina. Additional spermatozoa are found in the uterus externus of H. lepida which could be an indication for internal fertilization. Spermatogenesis occurs in cysts in the testes of male H. lepida. In the vasa deferentia, the ductus ejaculatorius and the palpal bulb, the spermatozoa are embedded in homogenous secretion. The palpal bulb has a distal extension bearing a crown-like structure. The embolus is situated at the base of the extension. In memoriam of Konrad Thaler.  相似文献   

10.
    
This study describes the female genitalia of the tetrablemmid spiders Brignoliella acuminata, Monoblemma muchmorei, Caraimatta sbordonii, Tetrablemma magister, and Ablemma unicornis by means of serial semi‐thin sections and scanning electron microscopy and compares the results with previous findings on Indicoblemma lannaianum. Furthermore, the male palps and chelicerae are briefly described. The general vulval organization of females is complex and shows similarities in all of the investigated species. The copulatory orifice is situated near the posterior margin of the pulmonary plate. The opening of the uterus externus lies between the pulmonary and the postgenital plate. Paired copulatory ducts lead to sac‐like receptacula. Except for A. unicornis, the male emboli of all investigated species are elongated and thread‐like. However, they are too short to reach the receptacula. Hence, the spermatozoa have to be deposited inside the copulatory ducts. The same situation was also found in I. lannaianum. Females of this species store sperm encapsulated in secretory balls in their receptacula. The secretion is produced by glands adjoining the receptacula. The presence of paired fertilization ducts and spermatozoa in the uterus internus suggested that fertilization takes place internally in I. lannaianum. Secretory balls in the receptacula are found in all of the investigated species in this study, showing that sperm are stored in the same way. The place of fertilization may also be identical since dark particles, presumably spermatozoa, are located in the uterus internus of all investigated species except for T. magister. However, fertilization ducts are only found in B. acuminata and M. muchmorei. A sclerotized central process with attached muscles is present in A. unicornis, M. muchmorei, C. sbordonii and T. magister. Only in A. unicornis does the central process show an internal lumen and hold spermatozoa. In the other species, it could be used to lock the uterus during copulation in order to prevent sperm from getting into it as suggested for certain oonopid species. The uterus externus of all investigated species shows a sclerotized dorsal fold with attached muscles, previously described as “inner vulval plate.” Contractions of the muscles lead to a widening of the dorsal fold, thus creating enough space for the large oocytes to pass the narrow uterus externus. The males of all investigated species have apophyses on their chelicerae. At least in B. acuminata and A. unicornis, where females have paired grooves on the preanal plate, these apophyses allow males to grasp the female during copulation as described for I. lannaianum. © 2008 Wiley‐Liss, Inc.  相似文献   

11.
    
The female genital organs of the tetrablemmid Indicoblemma lannaianum are astonishingly complex. The copulatory orifice lies anterior to the opening of the uterus externus and leads into a narrow insertion duct that ends in a genital cavity. The genital cavity continues laterally in paired tube-like copulatory ducts, which lead into paired, large, sac-like receptacula. Each receptaculum has a sclerotized pore plate with associated gland cells. Paired small fertilization ducts originate in the receptacula and take their curved course inside the copulatory ducts. The fertilization ducts end in slit-like openings in the sclerotized posterior walls of the copulatory ducts. Huge masses of secretions forming large balls are detectable in the female receptacula. An important function of these secretory balls seems to be the encapsulation of spermatozoa in discrete packages in order to avoid the mixing of sperm from different males. In this way, sperm competition may be completely prevented or at least severely limited. Females seem to have full control over transferred sperm and be able to express preference for spermatozoa of certain males. The lumen of the sperm containing secretory balls is connected with the fertilization duct. Activated spermatozoa are only found in the uterus internus of females, which is an indication of internal fertilization. The sperm cells in the uterus internus are characterized by an extensive cytoplasm and an elongated, cone-shaped nucleus. The male genital system of I. lannaianum consists of thick testes and thin convoluted vasa deferentia that open into the wide ductus ejaculatorius. The voluminous globular palpal bulb is filled with seminal fluid consisting of a globular secretion in which only a few spermatozoa are embedded. The spermatozoa are encapsulated by a sheath produced in the genital system. The secretions in females may at least partly consist of male secretions that could be involved in the building of the secretory balls or play a role in sperm activation. The male secretions could also afford nutriments to the spermatozoa.  相似文献   

12.
The binding of the spermatozoon to the zona pellucida is a species-specific phenomenon. We have previously shown that the binding of hamster sperm to the homologous zona pellucida involves a sperm 26-kDa glycoprotein, the P26h, originating in the epididymis. In order to establish to what extent this sperm protein is involved in the species-specific recognition of the egg's extracellular coat, we have compared the inhibitory properties of anti-P26h antibodies in a sperm-zona pellucida assay using hamster and mouse gametes. Anti-P26h IgGs inhibit, in a dose-dependent manner, gamete interactions in both species, although in a less efficient manner in the mouse than in the hamster. While anti-26kDa Fab fragments are as efficient as the intact IgG to inhibit hamster sperm-zona pellucida binding, they have no effect on mouse gamete interaction. ELISA, Western blot, and immunohistochemical experiments have been performed in order to characterize the mouse antigen(s) recognized by the anti-P26h antiserum. ELISA and Western blots showed that this antiserum recognized two proteins on mouse spermatozoa that are less reactive than the hamster P26h. These antigens are localized in the acrosomal region of epididymal spermatozoa of both species. These results indicate that the hamster P26H involved in zona pellucida interaction has certain unique epitopes, while others are common to the sperm of both species. © 1995 Wiley-Liss, Inc.  相似文献   

13.
  总被引:2,自引:0,他引:2  
In Ciona intestinalis, sperm penetration through the egg vitelline coat is an essential event of fertilization. We investigated whether trypsin- and chymotrypsin-like enzymes are involved in this event. Inhibitors and peptide substrates for chymotrypsin-like enzymes blocked the overall process of fertilization in a concentration-dependent manner. The inhibitory activity was specifically exerted on the step of sperm penetration. Chymotrypsin-like protease activity was identified in spermatozoa with the fluorogenic synthetic substrate Suc-Ala-Ala-Phe-AMC, which was the most effective substrate in blocking sperm penetration. These data indicate that a chymotrypsin-like protease activity is a sperm lysin of Ciona intestinalis.  相似文献   

14.
Synopsis This study examined the effects of various pH values on sperm motility times of white suckers,Catostomus commersoni, from two artificially acidified lakes in the Experimental Lakes Area (ELA), northwestern Ontario. White sucker sperm were active (motile) in water at all pH values tested (3.0–7.0). The maximum sperm motility time was 76.9 seconds and the minimum time was 51.9 seconds. Sperm motility times of fish from Lake 302N were similar to those of fish from Lake 223 at all pH values except pH 5.0 and 5.5. At these two pH values, sperm motility times of Lake 223 fish were longer than those of Lake 302N fish. In both lakes sperm motility at ambient lake pH levels (Lake 223 + 5.1, Lake 302N + 6.3) were similar to those at pH 7.0. Motility times of all fish tested were within the range of time during which fertilization normally occurs, indicating that reproductive failures in Lake 223 were probably not caused by impairment of sperm motility times.  相似文献   

15.
There is limited information on bobcat ejaculate traits and sperm cryopreservation and fertilizing ability. Bobcats were electroejaculated under general anesthesia in November (autumn) and April (spring), and endocrine and sperm traits were characterized. Testosterone (mean ± SEM: 0.90 ± 0.15 ng/mL) was not different between sampling times, but cortisol (average: 13.95 ± 1.73 μg/dL) was significantly higher in April. Average number of spermatozoa was 10.0 ± 3.4 × 106 sperm/ejaculate, with values being significantly higher in April. Sperm motility (average 55.7 ± 5.8% motile sperm) was not different between sampling times. The proportion of normal spermatozoa in the ejaculate (average: 14.7 ± 2.1%) was significantly higher in April, but the percentage of spermatozoa with intact acrosomes (average: 43.7 ± 3.8%) was significantly higher in autumn. Spermatozoa were cryopreserved in a Tes-Tris-based diluent (TEST) or Biladyl, both containing 20% egg yolk and 4% glycerol. Diluted sperm were loaded into straws, refrigerated using a programmable thermoblock with a dry chamber, frozen in nitrogen vapors, thawed, and incubated in F-10 medium with 5% fetal bovine serum for up to 3 h. After cryopreservation in TEST, there were about 50% motile sperm upon thawing, and survival was high during incubation post-thaw. Cryopreservation in Biladyl led to similar results, but motility decreased substantially during incubation post-thaw. Bobcat spermatozoa fertilized domestic cat oocytes matured in vitro. Fertilization rates were higher for sperm collected in April and cryopreserved in TEST (46%) than for those cryopreserved using Biladyl (<3%). Fertilized oocytes cleaved in culture, and some (27%) reached the morula stage. This study has allowed us to gain further baseline information on bobcat reproduction, explore sperm cryopreservation conditions, and show that fertilizing capacity can be tested using in vitro-matured cat oocytes. These results will be important for future conservation efforts.  相似文献   

16.
The report is part of a continuing study in which we employ monoclonal antibodies to membrane domains and internal organelles of rat spermatozoa in order to trace events during maturation, capacitation, fertilization, and early development. In the present study, we have used immunocytochemistry at the light and EM levels to localize one antibody, 5A5, to the fibrous sheath and a second, 3D5, to the outer mitochondrial membrane. Antibody 5A5 does not stain the fibrous sheath of spermatozoa of rodents other than the rat, while 3D5 can be localized to the outer mitochondrial membrane of rat, hamster, and mouse spermatozoa. In order to follow these antibodies during fertilization and early embryogenesis, we developed a method to stain internal components of zygotes and early embryos. Our findings suggests that the fibrous sheath disappears prior to the first cleavage and that mitochondria can be detected up to the 2-cell stage in mouse and the 4-cell stage in rat. © 1994 Wiley-Liss, Inc.  相似文献   

17.
Acrosomal protease activation is regarded as an important event triggered by acrosomal reaction and leading to sperm passage through zona pellucida. Mammalian acrosome has an internal acid pH that probably helps to maintain inactive proenzymes that otherwise could be precociously activated and prevent normal fertilization. In this work, we have studied the effect of bafilomycin A1, a potent and specific inhibitor of vacuolar H(+)-pump (V-ATPase), on acrosome reaction and proacrosin activation. We used the pH-sensitive probe Lysotracker Green DND-26 to monitor qualitatively intra-acrosomal pH in cauda epididymal mouse spermatozoa. Our results showed that loss of Lysotracker label induced by bafilomycin A1 (acrosome alkalinization) did not induce acrosome reaction or proacrosin activation. We also developed a new technique for imaging the acrosome, and for evaluating the acrosome reaction, in live mouse spermatozoa using Lysotracker DND-26. These results showed that the V-ATPase is a key regulator of mammalian acrosome pH, and that acrosome alkalinization is not the only prerequisite to activate proacrosin under in vivo conditions. Our results suggest that acrosome alkalinization and acrosome reaction are two processes that could be independently regulated during mammalian sperm capacitation.  相似文献   

18.
Caltrin proteins from seminal vesicle content of the guinea pig bind with great specificity to different regions of the spermatozoa. Indirect immunofluorescence studies with polyclonal antibodies showed that caltrin I binds to the head, on the acrosomal cup, while caltrin II binds on the principal tail and the neck. No fluorescence was detected either in the midpiece or in the post-acrosomal area of the head when sperm were exposed to either of the caltrins. Calcium-induced hyaluronidase release, which occurs during the acrosomal reaction, was dramatically inhibited by caltrin I (approximately 85% inhibition). Caltrin II was less effective in preventing the enzyme release (approximately 50% inhibition). Chemical modification of the structure modified the biological activity of the two caltrins. Reduction and carboxymethylation of the cysteine residues diminished the inhibitory activity on 45Ca2+ uptake and reduced the ability of the proteins to react with their antibodies. Removal of the carbohydrate portion by chemical deglycosylation transformed the inhibitor proteins into enhancers of calcium uptake into the spermatozoa. Caltrin proteins from the guinea pig appear to play the same physiological role as bovine caltrin, regulating specifically calcium transport across the spermatozoal membranes related with the acrosome reaction and hyperactivation process. The dual behavior of caltrins to inhibit or enhance Ca2+ uptake enables them to fulfill this function. Nevertheless, molecular mechanisms different from those described for bovine caltrin seem to be involved in the control of the functional activity of the guinea pig caltrins.  相似文献   

19.
Membrane cofactor protein (MCP) is a complement regulatory protein that acts as a cofactor for the cleavage of C3b and C4b by the serine protease factor I. We have previously reported the characterization of a functional MCP molecule on the acrosomal membrane. This protein migrated as a single band with a molecular weight of 40,000 Da, which is 10,000–20,000 Da smaller than the known MCP molecules, and is devoid of N-and O-linked sugars. We have proposed that the difference in molecular weight resulted from the lack of sugars. To investigate if this is due to the absence of glycosylation sites, we have characterized a cDNA clone from a human testis cDNA library. This cDNA corresponds to a peculiar MCP form previously described, which is characterized by the presence of the serine/threonine/proline-rich exon C (STPC) and the cytoplasmic tail known as CYT2, and we conclude that the absence of mature oligosaccharide of the sperm MCP cannot be totally attributed to a defect of N- and O-glycosylation sequences but rather reflects an alteration of the mechanisms of glycosylation in spermatozoa. The presence of functional MCP on the acrosomal membrane, as well as the other complement regulatory protein, decay-accelerating factor, strongly suggests that these proteins may act concomitantly to protect the acrosome-reacted spermatozoa from the attack of the complement present in the female genital tract. © 1993 Wiley-Liss, Inc.  相似文献   

20.
    
Summary Spermatozoa with intact acrosomes, as well as those coming into contact with the ovum at a smaller angle, and morphologically abnormal spermatozoa reach the plasma membrane of the ovum via an extensively dissolved zone of the inner layer of the vitelline membrane. This zone is assumed to be formed by overlapping of two or more tunnels formed by spermatozoa that had previously come into contact with the ovum.When a spermatozoon comes into contact with the plasma membrane of the ovum, many cytoplasmic processes extend outwards and cover it. Thereafter, the plasma membranes of the processes fuse, thereby phagocytizing the spermatozoon. It is assumed that the phagocytized spermatozoa cannot undergo transformation into male pronuclei and that they degenerate soon after phagocytosis.The authors are greatly indebted to Assoc. Prof. Osamu Koga for his valuable advice. The authors also wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advice. This investigation was supported by a grant from the Ministry of Education of Japan (156185)Previous name: Fukashi Okamura  相似文献   

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