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1.
This essay proposes that highly localized communication between free and bound spermatozoa in the caudal portion of the oviduct acts to regulate the numbers detaching from the epithelium and progressing to the site of fertilization close to the time of ovulation. Low initial sperm:egg ratios are essential for monospermic fertilization. Liberation of surface macromolecules and metabolic prompting from activated spermatozoa, together with altered patterns of sperm movement and dynamic differences in intracellular Ca2+ ion status between neighboring sperm cells, would influence the progressive release of spermatozoa from the reservoir in the oviduct isthmus. Different intensities of preovulatory epithelial binding, reflecting a range of states in the sperm surface membranes and associated proteins, would provide a further explanation for a chronologically staggered periovulatory detachment of spermatozoa. Intimate sperm–sperm interactions within the confines of the oviduct isthmus offer a sensitive means of fine-tuning the vanguard of competent male gametes reaching the isthmo-ampullary junction.  相似文献   

2.
《Theriogenology》2015,83(9):1273-1280
This study was designed to investigate if the characteristics of feline urethral sperm can be affected by high dilution in an artificial medium. The semen collected by urethral catheterization from eight male cats was evaluated for sperm concentration and motility and subsequently diluted with a TRIS-based extender to the concentration of spermatozoa 10 × 106/mL, 5 × 106/mL, and 1 × 106/mL. Immediately after the extension samples were assessed for motility, cell viability using SYBR-14 and propidium iodide, acrosome integrity using lectin from Arachis hypogaea Alexa Fluor 488 Conjugate, and propidium iodide and chromatin status by acridine orange. Compared with 10 × 106/mL dilution rate, spermatozoa diluted to 1 × 106 sperm/mL had a significantly lower proportion of motile (31.1% ± 19.8 and 0.7% ± 1.6, respectively, P < 0.05) and viable spermatozoa (88.3% ± 3.1 and 69.1% ± 12.8, respectively, P < 0.01). There was no dilution-related difference in the acrosome integrity (76.7% ± 11.9 vs. 75.9% ± 10.6) and chromatin status (defragmentation index, 3.3% ± 0.97 vs. 3.4% ± 1.7). These results indicate that feline urethral semen is susceptible to high dilution rate, and some sperm characteristics can be artifactually changed by semen dilution. It also suggests the potential role of seminal plasma in maintaining sperm motility and viability in high dilution rates.  相似文献   

3.
The ultrastructure of spermatozoa of the Pacific oysters Crassostrea gigas from an industrially polluted area on the Hsinchu City coast and a relatively clean aquaculture area on Penghu Island, Taiwan, was studied. Oyster gonads were sectioned and examined with light and transmission electron microscopes. The number of spermatozoa in the acinus lumen was significantly lower in oysters from the polluted area than that from the relatively clean area (160 ± 33 cells per 0.01 mm2 against 280 ± 42 cells per 0.01 mm2, respectively, P < 0.01). Oysters from the polluted area on the Hsinchu City coast had 26.6% spermatozoa with damaged acrosome, coarsely granular chromatin and electron-lucent areas in the nucleus; cell membrane, mitochondria and flagellum were frequently absent in these spermatozoa. By contrast, oysters from the clean area on Penghu Island had 0.4% spermatozoa with the same impairments. Sea water temperature and salinity were similar in the two areas, whereas concentrations of nitrogenous nutrients and heavy metals (e.g., cadmium, copper, and zinc) were higher in the industrially polluted area. It is suggested that high percentage of impairments in the spermatozoa of oysters from the industrial area is attributable to environmental pollution.  相似文献   

4.
To assess the ability of ram spermatozoa to bind to oocytes, spermatozoa (2.5–200 × 106/500μ1) taken from the rete testis, or from various regions of the epididymis (head, body, and tail) were mixed with cumulus-free heterologous oocytes obtained from immature superovulated rats. After incubation for 30–45 min in Parker 199 Hepes medium at 35°C, testicular spermatozoa were unable to bind to the zona at any of the concentrations used. However, spermatozoa from the middle body of the epididymus were able to bind to the zona and this binding reached a maximum in the distal body and in the tail of the epididymis. The spermatozoa were bound by their heads. Electron microscopy showed that the plasma membrane and the acrosome of the bound sperm remained intact, without any sign of an acrosome reaction.  相似文献   

5.
The capacity to undergo the acrosome reaction and subsequent fusion with egg plasma membrane was examined in rete testicular and cauda epididymal spermatozoa from boars. Sperm penetration assay using zona-free hamster eggs demonstrated that the penetration rates for rete testicular spermatozoa preincubated for induction of the acrosome reaction for 2 and 3 h were 55% and 97%, respectively. However, most of the eggs (93%) were penetrated with polyspermy by cauda epididymal cells preincubated for 2 h. Results obtained by the triple-stain technique revealed the percentages of acrosome-reacted spermatozoa in the rete testicular and cauda epididymal samples preincubated for 3 h to be 61% and 74%, respectively. These results indicate that many rete testicular spermatozoa possess the capacity to undergo the acrosome reaction and subsequent fusion with egg plasma membrane in vitro, which appears to be completely established only after sperm transit through at least the proximal part of the epididymis. © 1993 Wiley-Liss, Inc.  相似文献   

6.
In cows undergoing spontaneous oestrous cycles and mated during the first 6 hours of oestrus, the distribution of spermatozoa in the oviduct isthmus and changes in their surface membranes and neighbouring epithelium have been examined shortly before and after ovulation. In agreement with previous histological studies, relatively few spermatozoa were detected in the oviduct lumen: most were located in the caudal isthmus before ovulation, frequently among folds and in the presence of a viscous secretion. A majority of spermatozoa in this region showed strands and droplets of secretory material distributed over the anterior portion of an intact head before ovulation, whereas distribution of material over the post-nuclear cap of spermatozoa close to vesiculation or already acrosome-reacted was characteristic of the post-ovulatory situation. These changes in sperm head membranes were viewed as an expression of the completion of capacitation, and seemingly permit microvillous engagement with the rostral tip of the head. In conjunction with a narrow lumen and viscous secretions in the caudal isthmus, microvilli may thus serve to regulate periovulatory sperm progression towards the site of fertilisation, and be the basis of intermittent phases of adhesion to the oviduct epithelium as seen by phase-contrast microscopy. Although cilia do not similarly engage the heads of bull spermatozoa (cf. boar spermatozoa), they may act to regulate progression of capacitated spermatozoa by contacting the principal piece of the flagellum. In the light of these observations, changes in the molecular composition of sperm surface domains during the process of capacitation in vivo now require specific definition.  相似文献   

7.
《Theriogenology》2016,86(9):1680-1687
The aim of the present study was to evaluate small follicle number, oocyte yield, and in vitro embryo production (IVEP) in Zebu beef cows treated long term with a GnRH agonist to suppress ovarian follicular growth. Nelore (Bos indicus) cows (n = 20) showing regular estrous cycles were randomly assigned to one of two groups: control (n = 10, placebo ear implant without a GnRH agonist); GnRH agonist (n = 10, GnRH agonist ear implant containing 9.4-mg deslorelin). All cows underwent an ovum pick-up (OPU) session 14 days (Day 14) before the start of treatments (Day 0) followed by seven OPU–IVEP procedures at 30-day intervals (Days 0, 30, 60, 90, 120, 150, and 180). Semen from a single batch of a previously tested bull was used for all the IVEP. Cows treated with agonist reported a decrease over time in the proportion of animals with a (CL; P ≤ 0.05) and large follicles (>10 mm, P ≤ 0.05). These cows had a lesser number of medium + large follicles (>5 mm; 1.74 ± 0.5 vs. 4.13 ± 0.5; P ≤ 0.05), greater number of small follicles (2–5 mm; 44.3 ± 2.8 vs. 30.8 ± 1.8; P ≤ 0.05), greater yield of cumulus-oocyte complexes (COCs; 21.0 ± 2.3 vs. 15.6 ± 1.9; P ≤ 0.05), greater proportion of COCs cultured (79.2 vs. 73.9%; P ≤ 0.05), COCs cleaved (10.6 ± 1.5 vs. 6.8 ± 1.1, P ≤ 0.05), and cleaved rate (52.8 vs. 44.3%; P ≤ 0.05) compared with control cows. The number (3.4 ± 0.7 vs. 3.0 ± 0.6; P > 0.05) and proportion (16.5 vs. 19.1%; P > 0.05) of blastocysts produced were similar between agonist and control cows, respectively. The study has shown that Zebu beef cows treated long term with a GnRH agonist had follicular growth restricted to small follicles. This did not compromise the ability of oocytes to undergo IVF and embryonic development.  相似文献   

8.
To facilitate the study of interactions between equine spermatozoa and homologous oviduct epithelial cells, we developed an assay to count labelled spermatozoa bound to oviduct epithelial cell (OEC) monolayers and used the assay to compare the binding ability of spermatozoa from different stallions. Washed spermatozoa from three stallions were incubated with the fluorochrome Hoechst 33342 (5 μg/ml) for 1 min. Spermatozoa were then layered over confluent monolayers of oviduct epithelial cells in 2 cm2 culture wells. Coculture treatments comprised five concentrations of spermatozoa (105, 5 × 105, 106, 2.5 × 106, and 5 × 106 per well). Cocultures were incubated for 30 min before unattached spermatozoa were aspirated in coculture supernatant. Fluorescent videoimages of attached spermatozoa were digitized, and attached spermatozoa were counted by image processing and analysis. Four wells (replicates) of each concentration were allocated within each ejaculate, and ejaculates were blocked by stallion for ANOVA. The total number of spermatozoa bound was not different between replicate wells (P > 0.1). Stallion, ejaculate, concentration, and all higher level interactions influenced total spermatozoa bound (P < 0.00001). Coefficients of variation between replicates were lowest for inseminate concentrations between 106 and 5 × 106 spermatozoa per well. Within the ejaculate, a log linear relationship exists between the number of bound spermatozoa and a spermatozoal concentration of the inseminate between 5 × 105 and 5 × 106 spermatozoa per well. This assay provides a reliable method of determining numbers of spermatozoa bound to somatic cells in vitro. Furthermore, differences exist in the ability of spermatozoa from different stallions to bind OEC monolayers. © 1996 Wiley-Liss, Inc.  相似文献   

9.
Cryopreserved semen allows the use of single ejaculates for repeated analyses, potentially improving IVF consistency by eliminating interejaculate variability observed with fresh semen. However, the freezing and thawing processes result in compromised sperm function and IVF success. Semen samples are often screened for motility before use for IVF. Samples that are below a designated motility threshold may be discarded. Our objectives were to determine if post-thaw sperm motility, other traits that may be indicative of sperm function, or a novel assay of oviduct binding were related to IVF success. Semen from 16 boars was cooled to 15 °C for overnight shipment before cryopreservation. Semen was thawed and motility was recorded microscopically and confirmed using computer-automated sperm assessment. Each sample was tested by IVF in two to three independent replicates. Regression and correlation analyses were employed to determine the interrelationships between sperm traits and the relationships between post-thaw motility, sperm-oviduct binding and IVF outcomes. Among the sperm traits examined, sperm acrosome integrity was negatively correlated with post-thaw motility (r2 = 0.64) but not with IVF results. The number of sperm bound to oviduct aggregates was correlated with IVF polyspermy rates (r2 = 0.62, P < 0.05) but less with overall IVF rates (r2 = 0.31, P > 0.10). There was some relationship of post-thaw motility with IVF monospermic fertilization (P = 0.06, r2 = 0.08) but not to other IVF outcomes. Our results indicate that post-thaw motility of frozen-thawed boar sperm is strongly related to acrosome integrity but has limited use for predicting IVF success. The number of sperm bound to oviduct cells was related to IVF polyspermy rates and may be more indicative of in vitro sperm function than traditional sperm motility and acrosome status evaluation.  相似文献   

10.
Short-term storage of semen is a necessary key procedure in fish; it allows maximizing the use of gametes. Nevertheless, sperm quality decreases during storage has been associated with oxidative stress damage due to an increase in reactive oxygen species (ROS) during storage. This study was designed to optimize a short-term storage protocol for Coho salmon (Oncorhynchus kisutch) spermatozoa, evaluating the effect of extender dilution and the addition of butyl-hydroxytoluene (BHT) antioxidant on sperm function parameters. In the first experiment, fresh semen was diluted in Storfish®: extender dilution (1:2 and 1:3) and a control sample undiluted and stored at 4 °C for 7-days. In both experiments motility (MO), viability and integrity of plasma membrane, mitochondrial membrane potential (MMP) and superoxide anion level (O2) were evaluated at 0, 3 and 7 days. Result shows that, 1:3 dilution maintained a higher sperm function for a longer period time. In the second experiment, spermatozoa were suspended in Storfish® (1:3) supplemented with two different concentrations of BHT (1.0 mM and 2.0 mM) and a control sample without antioxidant and stored at 4 °C for 7 days. The results demonstrated that, antioxidant-supplemented samples greater MO than control samples (P < 0.05). The viability remained >75% during storage in all groups. MMP was higher in 2.0 mM BHT compared to 1.0 mM and control (P < 0.05), in addition, this concentration reduced O2 level (P < 0.05). In conclusion, sperm: extender dilution 1:3 and adding of 2.0 mM BHT in sperm storage extender may enhance protection sperm function in Oncorhynchus kisutch against effects harmful of the oxidative stress during the in vitro storage.  相似文献   

11.
Con A Receptors from the sperm plasma membrane were quantitated (using 3H acetyl-Con A) along the epididymal duct; they diminished in the second part of the epididymis as compared to the epididymal head. Glycoproteins having affinity for Con A were partially characterized: washed spermatozoa from rete testis (= testicular spermatozoa), middle corpus and distal cauda epididymis were labelled (125I Na). Proteins of their plasma membrane were extracted (Triton ×100, 0.1% and chromatography affinity): differences appeared in ACA44 profiles from 125I Con A Glycoprotein extractions between testicular spermatozoa (2 major peaks Kav= 0.41 and 0.52) and epididymal spermatozoa (3 major peaks Kav= 0.33–0.34, 0.41 and 0.52 and additional minor peaks between 0.66 and 1.00). The peak Kav= 0.41 diminished considerably on epididymal spermatozoa as compared to testicular spermatozoa.  相似文献   

12.
Abstract

The solubilized perivitelline layer (PL) of the chicken ovum contains one or more components which behave in a manner analogous to sperm-receptors. Electrophoretic analyses of solubilized PL confirmed the existence of three major glycoproteins having apparent molecular weights of 33,000, 53,500 and >200,000. The role of carbohydrate in sperm receptor activity was evaluated by extensive deglycosylation of the solubilized PL with trifluoromethanesulfonic acid (TFMS). Sperm receptor activity as measured by an in vitro competition assay was extremely sensitive to TFMS. Pretreatment of spermatozoa with solubilized PL exposed only to TFMS buffers inhibited sperm attachment and digestion of intact PL by 81% (9.67 ± 1.76 sperm/mm2) as compared with the controls (i.e., no pretreatment of spermatozoa with solubilized PL; 51.33 ± 6.24 sperm/mm2), a value similar to that observed with spermatozoa exposed to untreated solubilized PL (0.17 ± 0.17 sperm/mm2). In comparison, PL treated with TFMS inhibited sperm attachment and digestion of intact PL by less than 26% (38.33 ± 5.88 sperm/mm2) as compared with the control. These data indicate that removal of both N- and O-linked oligosaccharides from components of the chicken PL results in elimination of its sperm receptor activity.  相似文献   

13.
In order to examine whether sperm migration into and through the oviduct follows an invariable pattern or is subject to regulation, rats in proestrus, estrus, metestrus, or diestrus were inseminated in the upper third of each uterine horn with 10-20 million epididymal spermatozoa. Three or eight hours later, the numbers of spermatozoa free and adhering to the epithelium in the ampullary and isthmic segments were determined. A significantly higher number of spermatozoa were recovered in estrus than in other stages, at 3 h than at 8 h, and at all stages from the isthmus than from the ampulla. Spermatozoa adhering to the epithelium were observed only in proestrus and estrus and in the isthmus. The effect of exogenous estradiol-17beta (E2) and progesterone (P4) on sperm migration was investigated in rats in which the estrous cycle was inhibited pharmacologically. E2 facilitated sperm migration into the oviduct and P4 antagonized this effect, whereas P4 alone had no effect. Concomitant treatment with E2+P4 induced adhesion of spermatozoa to the oviductal epithelium. In conclusion, the pattern of sperm migration into and through the rat oviduct varies with the stage of the cycle, being dependent on E2 and P4. The adhesion of spermatozoa to the rat oviductal epithelium is stage- and segment-specific and requires the combined action of both hormones.  相似文献   

14.
15.
Reproductive ducts of male and female soft-shelled turtles, Trionyx sinensis were examined throughout the year (March, May, September, December) using brightfield and electron microscopes (TEM and SEM), to determine the location and histomorphological characteristics of sperm storage structures as well as their changes at different phases of the seasonal reproductive cycle. Sperm stored in the epididymis were also examined. In the male, spermatogenesis is initiated in spring (May), and then the mature sperm are released in autumn as an episodic event. Spermatogenesis is inactive in winter. However, in this species, the epididymis contains sperm throughout the entire year. Sperm observed in the epididymis are intact and some structures are uniquely different from other reptiles, and is characterized by 35–40 concentric mitochondria with a dense core in the centre. Many glycogen granules are observed in the cytoplasm of the midpiece. However, the epithelial cell type of epididymal duct change in different seasons. The cells are fully developed with a highly secretory activity in September. The materials secreted from the epithelium might have the function as nourishment for the stored sperm. Sperm storage structures in the form of tubules are observed in the wall of the isthmus of the oviduct in hibernating females but are absent in the groups of May and September. These tubules develop either by folding or fusion of the oviductal mucosal folds and are lined by both ciliated and secretory cells. These tubules might provide a microenvironment for the sperm to enable its long-term storage. After being separated 4 months (December–March) from the male, sperm are observed in the tubules of the isthmus of the oviduct. The unique character of the sperm combined with the special sperm storage structures enable the sperm to maintain fertility and activity during their storage.  相似文献   

16.
Tissue pieces from the caput epididymidis of the rat were incubated in vitro with (35S) methionine to produce radioactive secretory proteins. The radioactive secretory proteins so formed were tested for their ability to bind to washed rat spermatozoa collected from the rete testis and cauda epididymidis, and to rat erythrocytes. The sperm and erythrocytes bound approximately 5% of the total radioactive protein. Binding was protein-specific in that only selected proteins became associated with the cells. Binding was not cell-specific, however, since testicular spermatozoa, caudal spermatozoa, and erythrocytes all bound the same proteins to a similar degree.  相似文献   

17.
No study has systematically studied the relevance of original Izumo strain of spontaneously hypertensive rats (SHR/Izm) as a stroke model. Furthermore, both SHR/Izm and stroke-prone SHR/Izm (SHRSP/Izm) are commercially available, and recent progress in genetic studies allowed us to use several congenic strains of rats constructed with SHR/Izm and SHRSP/Izm as the genetic background strains. A total of 166 male SHR/Izm and 17 male SHRSP/Izm were subjected to photothrombotic middle cerebral artery (MCA) occlusion with or without YAG laser-induced reperfusion. The pattern of distal MCA was recorded. Infarct volumes were determined with 2,3,5-triphenyltetrazolium chloride. At 24 or 48 h after MCA occlusion, infarct volumes in the permanent occlusion and 2-h occlusion groups (88 ± 22 [SD] and 87 ± 25 mm3, respectively) were significantly larger than that in the 1-h occlusion group (45 ± 14 mm3), indicating the presence of sizeable zone of penumbra. Infarct size in SHRSP/Izm determined at 24 h after MCA occlusion was fairly large (124.0 ± 34.8 mm3, n = 10). Infarct volume in SHR/Izm with simple distal MCA was 76 ± 19 mm3, which was significantly smaller than 95 ± 22 mm3 in the other SHR/Izm with more branching MCA. These data suggest that this stroke model in SHR/Izm is useful in the preclinical testing of stroke therapies and elucidating the pathophysiology of cerebral ischemia/reperfusion.  相似文献   

18.
《Theriogenology》2016,85(9):1536-1541
Although there is ample evidence for the effects of sperm head shape on sperm function, its impact on fertility has not been explored in detail at the intraspecific level in mammals. Here, we assess the relationship between sperm head shape and male fertility in a large-scale study in Manchega sheep (Ovis aries), which have not undergone any selection for fertility. Semen was collected from 83 mature rams, and before insemination, head shapes were measured for five parameters: area, perimeter, length, width, and p2a (perimeter2/2×π×area) using a computer-assisted sperm morphometric analysis. In addition, a cluster analysis using sperm head length and p2a factor was performed to determine sperm subpopulations (SPs) structure. Our results show the existence of four sperm SPs, which present different sperm head phenotype: SP1 (large and round), SP2 (short and elongated), SP3 (shortest and round), and SP4 (large and the most elongated). No relationships were found between males' fertility rates and average values of sperm head dimensions. However, differences in fertility rates between rams were strongly associated to the proportion of spermatozoa in an ejaculate SP with short and elongated heads (P < 0.001). These findings show how the heterogeneity in sperm head shape of the ejaculate has an effect on reproductive success, and highlight the important role of modulation of the ejaculate at the intraspecific level.  相似文献   

19.
20.
The aim of the present study was to evaluate different concentrations of royal jelly (RJ) supplemented extenders for post-thaw quality and incubation resilience of goat spermatozoa. Semen samples were collected from five goats. Pooled semen were diluted with soybean lecithin-based extender without RJ (control) or supplemented with different concentrations (0.25, 0.5 and 0.75%) of RJ (RJ0.25, RJ0.5, RJ0.75 respectively), at a final concentration of 150 × 106 spermatozoon/mL. Semen samples were assessed for sperm motility, plasma membrane integrity using hypoosmotic swelling test (HOST) damaged acrosome using FITC-Pisum sativum agglutinin (PSA-FITC) and DNA integrity using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).The addition of RJ (0.5%, 0.75%) led to higher percentages of subjective motilities (55.33 ± 2.29%, 57.67 ± 2.58%) compared to control and RJ0.25 groups (49.00 ± 2,80%, 51.67 ± 3.09%) (P < 0.05) following the freeze–thawing process. RJ0.5 and RJ0.75 groups had higher plasma membrane functional integrities (66.40 ± 1.34%, 68.20 ± 2.05%) and lower defected acrosome rates (24.60 ± 3.36%, 23.80 ± 2.27%) compared to the other groups (P < 0.05). DNA damaged spermatozoa in all groups were not significant (P > 0.05).In the end of incubation, motility and HOST rates of RJ0.5 (14.00 ± 3.87%, 31.20 ± 3.70%) and RJ0.75 (15.00 ± 3.27%, 29.20 ± 2.59%) groups were higher than control (8.00 ± 2.54%, 18.20 ± 3.11%) and RJ0.25 (9.00 ± 2.07%, 20.60 ± 2.88%) groups (P < 0.05). Also defected acrosome and DNA fragmation rates of RJ0.5 (32.20 ± 1.30%, 5.4 ± 0.55%) and RJ0.75 (29.20 ± 1.30%, 5.80 ± 0.45%) groups were significantly lower than control (38.80 ± 0.84%, 7.40 ± 1.34%) and RJ0.25 (39.80 ± 2.05%, 7.00 ± 1.58) groups. This study shows that RJ supplemented extenders have beneficial effect on goat sperm parameters at 0 h and 6 h of incubation.  相似文献   

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