Large Numbers Of Sperm Research Articles

Morphology of the Female Reproductive System in Carpocoris mediterraneus Tamanini, 1958 (Heteroptera: Pentatomidae)

Carpocoris mediterraneus is a polyphagous vegetarian. Adult females of C. mediterraneus were collected in Aksu, Antalya, in June 2018. In this study, the morphological structures of female reproductive system of C. mediterraneus, which has not been studied before, was investigated under light and electron microscopies. The female reproductive system of C. mediterraneus was composed of a pair of ovaries, lateral oviducts, a common oviduct, accessory gland and spermatheca. Each ovary consisted of six telotrophic meroistic type ovarioles. Each ovariole consisted a terminal filament, germarium, vitellarium, and pedicel. In the germarium region, there was a trophic core, trophocytes, young oocytes and prefollicular cells. Vitellarium contained three oocytes at various stages of maturity (previtelogenesis, vitellogenesis, choriogenesis). The ovarioles were connected via pedicels to a pair of short lateral oviducts and subsequently to a common oviduct. The spermatheca of C. mediterraneus consisted a spermathecal bulb, a pumping region, the distal duct, dilation region, proximal duct and genital chamber. The spermathecal bulb was oval in shape and strongly chitinized. Its lumen typically contains a large number of spermatozoa.

Effects of Cell Concentration During Cryopreservation On the Post-thaw Quality of Santa Inês Ram Sperm

BACKGROUND: Non-surgical artificial insemination techniques for sheep may benefit from larger numbers of sperm in the insemination dose because the ewe's cervix is convoluted and often cannot be traversed with an insemination gun resulting in deposition of the sperm at the os cervix. OBJECTIVE: To compare a range of sperm concentrations when cryopreserving semen from Santa Inês rams and determine the effects of this on post-thaw quality. MATERIALS AND METHODS: One ejaculate from each ram (n = 10) was diluted to four sperm concentrations to obtain the following groups: G – 400, G – 800, G – 1200, and G – 1600 x 10 6 sperm/mL. The semen samples were packaged in 0.25 mL straws, cooled to 5 ºC, cryopreserved in liquid nitrogen vapor, thawed in a water bath (40 ºC/20 s), and were analyzed for computerized kinetics, capacitation and acrosome integrity, and plasma membrane integrity of sperm. RESULTS: The G – 400 treatment resulted in samples with the highest linearity and progressive motion (P < 0.05) and had significantly greater plasma membrane integrity, and lower capacitation and acrosome reaction rates compared to G-1600 (P < 0.05). Overall, use of the G – 400 treatment resulted in better kinetics, less plasma membrane damage and less early capacitation. However, despite reducing the ejaculate yield and increasing the costs of the semen freezing process, the G – 800 and G – 1200 treatments make a greater absolute number of sperm with good kinetics, plasma membrane integrity and capacitation status available. CONCLUSION: Ram sperm concentration impacts cryopreservation, and higher concentrations may be advantageous if a single rtificial insemination protocol is desirable.

Sex steroids in diploid and triploid gibel carp (Carassius gibelio) of both sexes in different phases of the reproductive cycle

The changes in concentrations of 17ß-estradiol (E2), testosterone (T), 11-ketotestosterone (11-KT) in the gonads and plasma of diploid and triploid gibel carp (Carassius gibelio) from the Siemianowka Reservoir, the Vistula River drainage were quantified and compared using an enzyme immunoassay. The phase of gonad maturity was based on histological analysis and the gonadosomatic index. All fish had properly developed gonads in the pre-spawning, spawning and late spawning phases of the reproductive cycle in the fish collected in April, June and October, respectively. Diploid and triploid females and males did not differ in mean GSI in all reproductive phases. In October, ovaries of most females contained vitellogenic oocytes, testes had large numbers of spermatozoa. The hormone concentrations in both tissues depended mainly on the reproductive phase, but not on ploidy. The patterns of changes in E2 concentrations was similar in females and males. In the pre-spawning phase, diploid and triploid females showed differences in the concentrations of 11-KT in gonads and plasma, and T in plasma. Diploid males differed in pattern of T concentrations in gonads and plasma, while all males showed a similar pattern of 11-KT plasma concentrations. Spermatozoa observed in triploid males suggest that they participate in reproduction. Gibel carps, regardless of ploidy, had an extended period of reproduction, which makes this invasive species a potentially greater threat to native ichthyofauna. The sex androgen concentrations that differed between 2 n and 3 n females could be physiological factors potentially contributing to the coexistence of gynogenetic C. gibelio females and sexual diploids.

Morphology of female reproductive system of Mediterranean flatheaded peachborer, Capnodis tenebrionis (Linnaeus, 1761) (Coleoptera: Buprestidae)

AbstractCapnodis tenebrionis causes damage in many species of Rosaceae. The present study investigates on the morphology of the female reproductive system of C. tenebrionis. The female reproductive system of C. tenebrionis has a pair of ovaries, lateral oviducts, a common oviduct, spermatheca, and bursa copulatrix. Each ovary in C. tenebrionis consists of approximately 24 telotrophic meroistic type ovarioles. The ovarioles of C. tenebrionis have four regions (terminal filament, tropharium, vitellarium, and pedicel). Tropharium have trophocytes, young oocytes, and prefollicular cells. Vitellarium consists of previtellogenic, vitellogenic, and choriogenic oocytes. Previtellogenic oocyte is surrounded by cylindrical epithelial cells. Its ooplasm is homogeneous and basophilic. In vitellogenic oocyte, there are intercellular spaces between monolayered follicle cells. Its ooplasm has yolk granules and lipid droplets. Choriogenic oocyte are surrounded by chorion and single‐layered cylindrical cells. There are yolk granules and lipid droplets in its ooplasm which is asidophilic. In C. tenebrionis female, spermatheca and bursa copulatrix wall is surrounded by thin cuticular intima, monolayer epithelial, glandular cells, and muscle layer. Spermatheca lumen contains a large number of spermatozoa. Bursa copulatrix lumen is filled with secretory material. This study may be useful in terms of the morphology of mature female reproductive organs of Buprestidae and other coleopteran species.

DNA damage in human sperm: The sperm chromosome assay.

BackgroundSperm DNA damage is a major cause of pre‐ and post‐implantation embryonic loss in humans. However, the factors that control how and when such DNA damage occurs in human sperm are poorly understood.MethodsHere, I review information relating to sperm DNA damage that can be obtained from the sperm chromosome assays described in the existing literature.Main findingsThe sperm chromosome assays, which consist of interspecific in vitro fertilization or intracytoplasmic sperm injection using murine oocytes and subsequent chromosome analysis, indicate that the proportion of sperm showing DNA damage is initially low and there are larger numbers of sperm with potential membrane and DNA damage that are induced after ejaculation and separation from the seminal plasma. Other assays that directly detect sperm DNA (e.g., TUNEL assays, Comet assays, and acridine orange test) are not able to distinguish and detect the initial and potential DNA damage. Furthermore, the positive values in these direct assays are influenced by the frequency of immotile sperm and amorphous sperm populations.ConclusionThe findings in the sperm chromosome assays show that further improvements in sperm preparation protocols may result in the reduction of sperm DNA damage, followed by more successful outcomes in infertility treatment.

Flagellar Cooperativity and Collective Motion in Sperm

Sperm have thin structures known as flagella whose motion must be regulated in order to reach the egg for fertilization. Large numbers of sperm are typically needed in this process and some species have sperm that exhibit collective or aggregate motion when swimming in groups. The purpose of this study is to model planar motion of flagella in groups to explore how collective motion may arise in three-dimensional fluid environments. We use the method of regularized Stokeslets and a three-dimensional preferred curvature model to simulate groups of undulating flagella, where flagellar waveforms are modulated via hydrodynamic coupling with other flagella and surfaces. We find that collective motion of free-swimming flagella is an unstable phenomenon in long-term simulations unless there is an external mechanism to keep flagella near each other. However, there is evidence that collective swimming can result in significant gains in velocity and efficiency. With the addition of an ability for sperm to attach and swim together as a group, velocities and efficiencies can be increased even further, which may indicate why some species have evolved mechanisms that enable collective swimming and cooperative behavior in sperm.

Impact of sperm concentration on sperm morphology of large white and landrace boars

The aim of the study was to determine the dependence of semen quality, frequency of sperm defects, and sperm dimensions and shape on sperm concentration in ejaculates of Large White and Landrace boars. A total of 648 ejaculates collected from 31 Large White and 30 Landrace boars were divided into three groups according to the criterion of sperm concentration. The physical characteristics of all ejaculates were determined, and morphological and morphometric examination of spermatozoa was performed. The characteristics of the ejaculates, frequency of sperm defects, and dimensions and shape of spermatozoa were shown to depend on the sperm concentration. Ejaculates with a high sperm concentration contain a large number of sperm, but have a smaller volume than ejaculates with a lower sperm concentration. Sperm from ejaculates with the lowest sperm concentration have larger dimensions than sperm from ejaculates with intermediate and high sperm concentrations. This is expressed in a larger head area and perimeter and in greater total sperm length. The dependence of the ejaculate characteristics and the size and shape of sperm on the sperm concentration is influenced by the breed. In the ejaculates of Landrace boars, these relationships are more pronounced than in Large White boars. An increased sperm concentration reduces the occurrence of the Dag defect but promotes the occurrence of sperm with a proximal droplet, a pseudodroplet, or a distal droplet.

Yüksek yağlı diyetle indüklenmiş obez sıçanların bozulmuş epididimal sperm parametreleri üzerine egzersizin iyileştirici etkisi

Objective: Obesity causes male infertility problems and affectsthe sperm quality. Recent studies have shown that exercise haspositive effects on male fertility. The present study aimed to showthe effects of swimming exercise on the epididymal sperm number,motility and morphology in hight fat diet (HFD)-induced obeserats.Materials and Methods: Four experimental groups (n=8 ineach group) were formed. Standard (STD) and STD+Exercise(STD+EXC) groups were fed with standard rat diet (6% of caloriesas fat); HFD and HFD+Exercise (HFD+EXC) groups were fedwith high fat diet (45% of calories as fat) for 18 weeks. The ratsin STD+EXC and HFD+EXC groups were trained by swimmingsessions (1 h per day for 5 days a week) during the last 6 weeks ofthe experiment. The left caudal epididymis was prepared to evaluatethe number, motility and morphology of the spermatozoa. The rightepididymal samples were processed for histological evaluation.Results: Normospermic parameters were seen in STD andSTD+EXC groups. Sperm number and motility decreased andspermatozoa with abnormal morphology increased significantly inHFD group when compared with STD group. A large number ofspermatozoa in the epididymal duct lumen and regular morphologyof the fibromuscular connective tissue were observed in STDand STD+EXC groups. Most of the epididymal ducts consistedof decreased amount of spermatozoal accumulation in the HFDgroup. Degenerated pseudostratified columnar epithelium withvacuole formation were additional findings in this group. On theother hand, swimming exercise had an enhancement effect onsperm parameters with prominent spermatozoal accumulation inthe ducts of epididymis in HFD induced obese rats.Conclusion: This study shows that HFD-induced obesitydecreased the number and motility of spermatozoa, increasedabnormal spermatozoa and caused disrupted epididymalmorphology. We hypothesize that exercise enhanced HFD-inducedspermatogenic and epididymal damages by the regulation of scrotalheat and possible inhibition of oxidative damage in the epididymis.

Life‐history and demographic traits of the marula fruit fly Ceratitis cosyra: potential consequences of host specialization

AbstractLife‐history strategies are diverse both across and within species, although the factors shaping this diversity are not fully understood. In the present study, we investigate the life‐history strategies of the marula fruit fly Ceratitis cosyra (Walker) (Diptera: Tephritidae) and how they differ between the sexes. We measure lifespan and age‐dependent reproductive effort in both sexes. In females, reproductive effort is measured as fecundity (egg counts) and for males, courtship behaviour, mating propensity and sperm transfer at ages 5, 15 and 25 days are assayed. Mean ± SE lifespan of flies is 104.6 ± 2.8 days, with females living on average 9 days longer than males. Total female fecundity and time until peak egg production both positively correlate with lifespan. The proportion of males courting and mating is similar at 5 and 15 days, although courtship activity increases and mating success decreases significantly by 25 days. The number of sperm transferred and sperm storage asymmetry are highest at 15 days, with 12 173 ± 826 sperm being stored per female after mating. We also compare life‐history traits in C. cosyra with other tephritids, aiming to determine how niche breadth might contribute to life‐history evolution. In comparison with other tephritids, C. cosyra has a long lifespan and a relatively low lifetime fecundity, although males transfer particularly large numbers of sperm during copulation. These life‐history traits may be associated with the seasonal availability of marulas, which are its preferred native host.

An autoregressive logistic model to predict the reciprocal effects of oviductal fluid components on in vitro spermophagy by neutrophils in cattle

After intercourse/insemination, large numbers of sperm are deposited in the female reproductive tract (FRT), triggering a massive recruitment of neutrophils (PMNs) into the FRT, possibly to eliminate excessive sperm via phagocytosis. Some bovine oviductal fluid components (BOFCs) have been shown to regulate in vitro sperm phagocytosis (spermophagy) by PMNs. The modeling approach-based logistic regression (LR) and autoregressive logistic regression (ALR) can be used to predict the behavior of complex biological systems. We, first, compared the LR and ALR models using in vitro data to find which of them provides a better prediction of in vitro spermophagy in bovine. Then, the best model was used to identify and classify the reciprocal effects of BOFCs in regulating spermophagy. The ALR model was calibrated using an iterative procedure with a dynamical search direction. The superoxide production data were used to illustrate the accuracy in validating logit model-based ALR and LR. The ALR model was more accurate than the LR model. Based on in vitro data, the ALR predicted that the regulation of spermophagy by PMNs in bovine oviduct is more sensitive to alpha-1 acid glycoprotein (AGP), PGE2, bovine serum albumin (BSA), and to the combination of AGP or BSA with other BOFCs.

Improved sperm kinematics in semen samples collected after 2 h versus 4–7 days of ejaculation abstinence

Does a short abstinence period of only 2 h yield spermatozoa with better motility characteristics than samples collected after 4-7 days? Despite lower semen volume, sperm concentration, total sperm counts and total motile counts, higher percentages of motile spermatozoa with higher velocity and progressiveness were detected in samples obtained after 2 h. Most studies that have assessed the effect of abstinence periods on sperm motility parameters in men with a sperm concentration below 15 million/ml have detected a higher percentage of motile spermatozoa in samples obtained after short abstinence periods. Studies of men with sperm concentrations above 15 million/ml have reported significantly decreased motile sperm counts after 24 h of abstinence compared with longer abstinence periods. This study had a controlled repeated-measures design based on semen samples from 43 male partners, in couples attending for IVF treatment, who had a sperm concentration above 15 million/ml. Data were collected between June 2014 and December 2015 in the Fertility Unit of Aalborg University Hospital (Aalborg, Denmark). Participants provided a semen sample after 4-7 days of abstinence followed by another sample after only 2 h. For both ejaculates, sperm concentration, total sperm counts, motility groups and detailed kinematic parameters were assessed and compared by using the Sperm Class Analyzer (SCA) computer-aided sperm analysis system before and after density gradient selection. The laboratory's local manual method (Makler chamber) was used for comparison. The second raw ejaculate demonstrated lower semen volume (P < 0.0001), sperm concentration (P = 0.003) and sperm counts in all motility sub-groups (P < 0.001) but higher percentages of spermatozoa with higher velocity (P < 0.01), progressiveness (P < 0.001) and hyperactivation (P < 0.001), compared with the first raw ejaculate. The first ejaculate in this study was also used for the IVF/ICSI treatments and therefore only patients with a semen volume ≥2 ml and concentration ≥15 million/ml were included. Further validation in large prospective randomized controlled trials, more purposely directed at normozoospermic males with partners having problems conceiving when there appears to be no female factor, is needed to confirm the potential advantage of using a second semen sample in improving fertilization and pregnancy rates in assisted reproduction. Despite the significantly lower semen volume, sperm concentration and total sperm counts in all motility sub-groups, the significantly higher percentage of spermatozoa with better motility characteristics (velocity, progressiveness and hyperactivation) in the second ejaculate, may provide and allow for a simpler and more effective selection of higher quality spermatozoa. This could prove to be an advantage for ART procedures such as intracytoplasmic sperm injection where a large number of spermatozoa is not needed. It can also be speculated that pooling two consecutive ejaculates obtained after 4-7 days and after 2 h, could be an advantage for intrauterine insemination where a large number of motile spermatozoa are needed. This study was supported by internal grants from the Department of Health Science and Technology, Faculty of Medicine, Aalborg University (Aalborg, Denmark). The SCA® was provided by a grant from 'Ferring Pharmaceuticals' to Aalborg University Hospital (H.I.N). G.V.D.H. is an external senior scientific consultant to Microptic S/L (Barcelona, Spain). H.A. has provided scientific input and presentations for Microptic S/L (Barcelona, Spain) on several occasions. All other authors declare no conflict of interest. N/A.

Comparative effects of human chorionic gonadotropin (hCG) and Ovaprim™ (sGnRHa + domperidone) on the reproductive characteristics of wild-caught male Longspine scraper, Capoeta trutta (Heckel, 1843)

The effectiveness of two different hormonal treatments or a saline control on sperm characteristics, plasma sex steroids and testes histology of male Longspine scraper, Capoeta trutta (Heckel, 1843) collected from the wild and maintained in captivity were tested. Fish injected with Ovaprim™ had significantly increased gonadosomatic index (GSI) and sperm volume, but had decreased spermatozoa concentration and spermatocrit compared with control. Fish injected with hCG had significantly decreased motility duration of their sperm, as well as decreased spermatozoa concentration and spermatocrit. Both treatments increased seminal plasma pH compared with control, while decreases in osmolality of seminal plasma occurred only in Ovaprim™-treated fish.Hormonal treatments altered the seminal plasma sodium (Na+), calcium (Ca2+), magnesium (Mg2+), glucose, phosphorus, urea, creatinine, alanine aminotransferase (ALT), and alkaline phosphatase (ALP) concentrations. However, neither treatment affected the seminal plasma potassium (K+), chloride (Cl−), uric acid, total protein, cholesterol, triglycerides, and aspartate aminotransferase (AST) concentrations.The concentration of 17,20β-dihydroxy-4-pregnen-3-one (DHP) in the plasma was significantly enhanced by Ovaprim™ treatment, but not by hCG. On the other hand, plasma testosterone (T) was significantly elevated by both treatments.Histological examination of the testes revealed stimulation of testicular maturation following treatment with Ovaprim™, with lobules observed that were filled exclusively with a large number of spermatozoa (spz). In summary, hormonal treatments stimulated steroidogenesis and spermiation in male C. trutta, with highest efficiency of the Ovaprim™ treatment. Therefore, it can be concluded that like many other cyprinids, dopamine inhibitory action was operating in C. trutta, thus requiring anti-dopaminergic and hormonal treatments to overcome this in order to maximize steroidogenesis and induction of spermiation. Statement of relevanceThe research I present in this paper is novel, as:•The effectiveness of exogenous hormones on male C. trutta reproduction under controlled conditions;•The effect of hormonal treatment on a wide range of seminal plasma compositions in C. trutta;•Valuable information which will assist commercial facilities in organizing and, spermiation success in this new aquaculture species.

Methods for Improving In Vitro and In Vivo Boar Sperm Fertility.

Fertility of boar spermatozoa is changed after ejaculation invivo and invitro. During processing for invitro fertilization (IVF), although spermatozoa are induced capacitation, resulting in a high penetration rate, persistent obstacle of polyspermic penetration is still observed with a high incidence. For artificial insemination (AI), we still need a large number of spermatozoa and lose a majority of those in the female reproductive tract. Fertility of cryopreserved boar spermatozoa is still injured through freezing and thawing process. In the present brief review, factors affecting fertility of boar sperm during IVF, AI and cryopreservation are discussed in the context of discovering methodologies to improve it.

Post-Coital Sperm Competence in Polygamous Animals: The Role of Sperm Traits in Species?Specific Strategies

In some species, the females may mate with more than one male. In these polygamous animals, both pre-coital and post-coital strategies are required for reproductive success. This mini review aims at providing an update of the role of sperm traits in species–specific strategies for post-coital sperm competence. According to the spermcompetition theory, in such species the reproductive success of the males then depends upon both the magnitude of inter-male rivalry and covert sperm competition. The number of inseminated sperm, the percentage of sperm without morphological abnormalities in the ejaculates, and the sperm velocity variables play a significant role in sperm competition. Therefore, males that transfer more sperm per ejaculate or who copulate more often, are more likely to sire offspring. The transfer of large numbers of sperm is also guaranteed by ejaculates with high sperm concentrations. Usually, males of polygamous species have large testes and produce ejaculates with high sperm concentrations. Sperm competition acts as a selective force driving evolutionary change in sperm morphology and function. The degree of sperm pleiomorphy shown by a species varies according to the degree of sperm competition its behaviour entails. For example, the ejaculates of very polygamous species have much more homogenous sperm with lower sperm abnormalities. Finally, recent studies in birds have shown that the straight-line velocity (VSL) value, the most accurate estimate of sperm cell velocity, is of great importance in competition scenarios. Thus, sperm with a higher VSL affords a male fertilization advantages over his rivals.

Boar sperm with defective motility are discriminated in the backflow moments after insemination

During insemination, a large number of spermatozoa are deposited in the female genital tract, but a very low percentage is able to colonize the site of fertilization. The influx of neutrophils into the uterine lumen and semen reflux (backflow) are known mechanisms that decrease the number of spermatozoa within the uterus. No report has attempted to ascertain whether the backflow is a random or selective process of the spermatozoa. In this work, sows were inseminated using two populations of spermatozoa in the same proportion: (1) unstained spermatozoa with high motility and (2) stained spermatozoa with low, medium, or high motility. Volume, number, and percentage of stained spermatozoa were evaluated in the backflow (collected at 0–15, 16–30, and 31–60 minutes after insemination). This article provides evidence that (1) the motility characteristics of the spermatozoa do not influence the percentage of sows with backflow, the volume and number of spermatozoa in the backflow; (2) the discarding of spermatozoa in the backflow is not specific during the first moments after insemination (0–15 minutes), whereas later (16–60 minutes), spermatozoa with defective motility (low and medium groups) are discarded in a higher proportion than high group in the backflow ([16–30 minutes: low, 85.13 ± 4.32%; medium, 72.99 ± 5.05%; and high, 54.91 ± 2.38%; P < 0.0001; 31–60 minutes: low, 87.16 ± 6.01%; medium, 87.02 ± 4.01%; and high, 59.35 ± 2.86%; P = 0.001]). Spermatozoa with poor motility are discarded in the backflow probably as a selective process, on the part of the female genital tract or as a result of the intrinsic low spermatozoa motility.

Histological observation of germ cell development and discovery of spermatophores in ovoviviparous black rockfish (Sebastes schlegeli Hilgendorf) in reproductive season

Black rockfish (Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season (October 2011–November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.

Current knowledge on the transport and fate of spermatozoa in the reproductive tract of the bitch.

Canine sperm transport, distribution, storage and detachment is a complex, dynamic and highly regulated process. Transport of sperm within the bitch's reproductive tract is rapid and is influenced by the method of semen deposition (natural mating or artificial insemination) and by the timing of breeding in relation to the day of ovulation. The fertile lifespan of spermatozoa in the reproductive tract of the bitch is considerably longer than in most other domestic species, and the main sperm reservoirs appear to be the uterine crypts and the distal part of the uterotubal junction, where spermatozoa attach by their heads to uterine epithelium. While several in vitro studies demonstrated prolonged motility and viability of canine spermatozoa after coincubation with uterine tube explants, spermatozoal storage has not been documented in the canine uterine tube isthmus or ampulla in vivo. Several factors, including exposure to progesterone, solubilized zona pellucida proteins and post-ovulation uterine tube fluid, appear to trigger membrane events resulting in capacitation-like changes with subsequent motility pattern changes (transitional and hyperactivated) that are associated with sperm detachment. After mating or insemination, a normal low-magnitude post-mating uterine inflammatory response occurs, evidenced by an influx of polymorphonuclear neutrophils (PMNs), increased uterine contractions and an increased uterine artery blood flow. Recently, it was also shown that normal dogs with cystic endometrial hyperplasia develop a more significant endometritis, show fewer mating-induced uterine contractions, a decreased ability of spermatozoa to bind to uterine explants in vitro and a slower uterine clearance after mating.

New insights into the functional morphology of the male copulatory apparatus of bullid gastropods

In this study, semi-thin sections stained with histochemical techniques and transmission electron microscopy were used to obtain new data about the morphology and function of the male copulatory apparatus of the cephalaspidean gastropod Bulla striata. The apparatus comprises a vestibule, a penial papilla and a prostate consisting of a coiled unbranched tube ending in a blind caecum. The penial papilla and the coiled tubular prostate are enclosed by a muscular sheath, which is continuous with the muscular tissue of the vestibule. The epithelium lining the lumen of the vestibule is formed by ciliated and mucus-secreting cells. Two new types of subepithelial secretory cells were discovered in this region. The penial papilla is a muscular structure without secretory cells in the epithelium lining the narrow lumen. The tubule that constitutes the prostate possesses a muscular wall and can be divided in three distinct regions: a non-secretory duct connected to the penial papilla, a glandular region rich in large secretory cells and the terminal caecum containing just a few small secretory cells. In the terminal blind caecum, the muscular sheath is fused with the muscular wall of the tubular prostate. Large numbers of spermatozoa were found in the glandular region and in the terminal caecum of the prostate. A new functional mechanism is proposed to explain penial eversion during copulation. This differs from a previous hypothesis in two main aspects: (1) existence of a permanent penial papilla in mature animals acting as a functional penis and (2) functional role of vestibule during copulation, which everts and surrounds the penial papilla, while the latter protrudes outwards.

Testicular Development in Cynomolgus Monkeys

The testes from 136 male cynomolgus monkeys were examined histopathologically in order to investigate the relationship between the development of spermatogenesis and testis weight, age, and body weight. At Grade 1 (immature), Sertoli cells and spermatogonia were the only cell classes in the testis. At Grade 2 (pre-puberty), no elongated spermatids were observed in the testis, although a few round spermatids and small lumen formation were observed. At Grade 3 (onset of puberty), all classes of germ cells were observed in the testis, although seminiferous tubule diameters and numbers of germ cells were small. Slight debris in the epididymis was observed in almost all animals. At Grade 4 (puberty), almost complete spermatogenesis was observed in the seminiferous tubules and it was possible to ascertain the spermatogenesis stage as described by Clermont, although tubule diameters and numbers of germ cells were small. There was less debris in the epididymis than at Grade 3. At Grade 5 (early adult), complete spermatogenesis was observed in the seminiferous tubules. At Grade 6 (adult), complete spermatogenesis in the seminiferous tubules and a moderate or large number of sperm in the epididymis were observed. Moreover, sperm analysis using ejaculated sperm was possible. Logistic regression analysis showed that testis weight is a good indicator of testicular maturity.

Genesis of spermatodesms in Tylopsis liliifolia (Orthoptera: Phaneropterinae) and their transit in the male genital tract

The spermatodesms of Tylopsis liliifolia form in the most proximal follicular cysts and are composed of a large number of sperm held together by a cap located in the anterior region of the acrosome. The cap is formed by short thin fibrils, loosely arranged at random, probably derived from secretory activity of cells of the cyst wall. Compared to other Tettigoniidae, a peculiar feature is acrosomal wings that twist gradually around the anterior region of the nucleus; at the end of the twisting process, the region of the sperm acrosome, observed in cross section, shows a typical spiral form. Spermatodesms do not undergo any substantial changes in the spermiduct. The epithelial cells of the wall have secretory activity and many show marked spermiophagic activity, which is conducted by epithelial cell protrusions that envelop the gametes, taking them into the cytoplasm. When removed from seminal vesicles and observed in vivo, spermatodesms show accentuated corkscrew movement, and when observed by SEM, slight torsion. Thus organized, spermatodesms are transferred to the spermatophore during mating, where they are transformed before reaching the seminal receptacle.