LALAPG variant of the Human Contraception Antibody (HCA) reduces Fc-mediated effector functions while maintaining sperm agglutination activity.

High rates of unintended pregnancies worldwide indicate a need for more accessible and acceptable methods of contraception. We have developed a monoclonal antibody, the Human Contraception Antibody (HCA), for use by women in vaginal films and rings for contraception. The divalent F(ab')2 region of HCA binds to an abundant male reproductive tract-specific antigen, CD52g, and potently agglutinates sperm. Certain other antibody activities mediated by the Fc region such as mucus trapping, complement-dependent cytotoxicity (CDC) and antibody-dependent cellular phagocytosis (ADCP) could have beneficial or negative effects. The purpose of this study was to document HCA Fc effector functions and determine whether an engineered variant of HCA with a modified Fc region, HCA-LALAPG, retains desirable contraceptive activity while minimizing Fc-mediated effects. Fab and Fc functions were compared between HCA and HCA-LALAPG. Fab activity was assessed using sperm agglutination and modified swim-up ("sperm escape") assays. Fc functions were assessed by CDC (sperm immobilization), ADCP, and cervical mucus penetration assays. HCA and HCA-LALAPG showed equivalent activity in assays of Fab function. In the assays of Fc function, HCA supported strong CDC, ADCP, and sperm trapping in cervical mucus whereas HCA-LALAPG demonstrated little to no activity. HCA and the HCA-LALAPG variant were both highly effective in the sperm agglutination assays but differed in Fc mediated functions. Use of the HCA-LALAPG variant for contraception in women could reduce antibody-mediated inflammation and antigen presentation but may have reduced contraceptive efficacy due to much weaker sperm trapping in mucus and complement-dependent sperm immobilization activity.

Canine-specific tail-in, head-out sperm agglutination.

An interesting pattern of tail-in, head-out sperm agglutination was identified in a Brucella canis seronegative subfertile dog. Centrifuged seminal plasma from this dog could induce a similar pattern of agglutination in six other dogs, but not in ejaculates from a single stallion and two rams. The agglutination pattern was short-lived and appeared to depend on motility of spermatozoa, although intensity of agglutination may have been affected by concentration of agglutinating factor.

Caffeine induces sperm detachment from sperm head-to-head agglutination in bull.

Sperm head-to-head agglutination is a well-known known phenomenon in mammalian and non-mammalian species. Although several factors have been reported to induce sperm agglutination, information on the trigger and process of sperm detachment from the agglutination is scarce. Since hyperactivated motility is involved in bovine sperm detachment from the oviduct, we focused on caffeine, a well-known hyperactivation inducer, and aimed to determine the role of caffeine in sperm detachment from agglutination. Agglutination rate of bovine sperm was significantly decreased upon incubation with caffeine following pre-incubation without caffeine. Additionally, we observed that bovine sperm were detached from agglutination only when the medium contained caffeine. The detached sperm showed more asymmetrical flagellar beating compared to the undetached motile sperm, regardless of whether before or after the detachment. Intriguingly, some sperm that detached from agglutination re-agglutinated with different sperm agglutination. These findings indicated caffeine as a trigger for sperm detachment from the agglutination in bull. Furthermore, another well-known hyperactivation inducer, thimerosal, also significantly reduced the sperm agglutination rate. Overall, the study demonstrated the complete process of sperm detachment from sperm head-to-head agglutination and proposed that hyperactivated motility facilitates sperm detachment from another sperm. These findings would provide a better understanding of sperm physiology and fertilization process in mammals.

Flow-cytometric analysis of membrane integrity of stallion sperm in the face of agglutination: the "zombie sperm" dilemma.

PURPOSE: To define the effect of sperm agglutination, associated with incubation under capacitating conditions, on accuracy of membrane assessment via flow cytometry and to develop methods to mitigate that effect. METHODS: Sperm motility was measured by CASA. Sperm were stained with PI-PSA or a novel method, LD-PSA, using fixable live/dead stain and cell dissociation treatment, before flow-cytometric analysis. Using LD-PSA, acrosome reaction and plasma membrane status were determined in equine sperm treated with 10 µm A23187 for 10 min, followed by 0, 1, or 2 h incubation in capacitating conditions. RESULTS: Using PI-PSA, measured membrane integrity (MI; live sperm) was dramatically lower than was total motility (TMOT), indicating spurious results ("zombie sperm"). Sperm aggregates were largely of motile sperm. Loss of motility after A23187 treatment was associated with disaggregation and increased MI. On disaggregation using LD-PSA, MI rose, and MI then corresponded with TMOT. In equine sperm incubated after A23187 treatment, as the percentage of live acrosome-reacted sperm increased, TMOT decreased to near 0. CONCLUSION: Flow cytometry assesses only individualized sperm; thus, agglutination of viable sperm alters recorded membrane integrity. As viable sperm become immotile, they individualize; therefore, factors that decrease motility, such as A23187, result in increased measured MI. Disaggregation before assessment allows more accurate determination of sperm membrane status; in this case we documented a mismatch between motility and live acrosome-reacted equine sperm that may relate to the poor repeatability of A23187 treatment for equine IVF. These findings are of profound value to future studies on sperm capacitation.

Effects of exogenous lactoferrin on characteristics and functions of bovine epididymal, ejaculated and frozen-thawed sperm.

The purpose of this study was to investigate effects of addition of lactoferrin on characteristics and functions of bovine epididymal, ejaculated, and frozen-thawed sperm. The addition of lactoferrin was significantly (p < .05) effective on increasing values of progressive motility, straightness, and linearity in caput epididymal sperm and values of motility in cauda epididymal sperm. When ejaculated sperm were incubated in capacitation medium, percentages of motile and progressively motile sperm decreased largely within the first period of 30 min, followed by only minor changes. However, the addition of lactoferrin significantly lessened the early decreases of these parameters and additionally promoted capacitation-dependent changes of chlortetracycline staining patterns (from F pattern to B pattern). In other experiments, when ejaculated sperm were exposed to oxidative stress with 100-µM H2 O2 , the addition of lactoferrin partially protected them from dysfunction of flagellar movement and loss of progressive movement. In final experiments with frozen-thawed samples incubated in the capacitation medium, the addition of lactoferrin effectively survived dying sperm and suppressed occurrence of sperm agglutination. These results may suggest biological and biotechnological potentials of lactoferrin for modulation of bovine sperm viability, motility, capacitation state, and preservation in vitro.

Effects of chelating calcium in cryopreservation extender on frozen-thawed dog semen / [Efeitos da quelação de cálcio no meio de criopreservação no sêmen descongelado de cão]

We evaluated the effect of reducing free calcium in the cryopreservation medium, using the calcium chelator ethylene diamine tetracetic acid (EDTA) at 0.3% and 0.5% concentrations. Three male mixed breed dogs were subjected to semen collection by digital manipulation (n=16). Each ejaculate was divided in three aliquots, and each one was diluted in TRIS-glucose-egg yolk extender with 6% glycerol and 0.5% Equex STM Paste® (TGE, control); and added with 0.3% EDTA (EDTA 0.3) or 0.5% EDTA (EDTA 0.5). Calcium concentration reduced in EDTA 0.3 and all the calcium ions were chelated in EDTA 0.5. The EDTA addition did not affect sperm morphology or plasma membrane integrity; however, by removing all free calcium (EDTA 0.5), the sperm motility reduced (64.7% in TGE and 45% in EDTA 0.5; p<0.05). Acrosome integrity and sperm binding ability were not improved by calcium chelation. The failure to prevent the premature AR may explain why sperm longevity was not affected by calcium removal. Thus, the partial or complete calcium removal, through EDTA addition, is not able to prevent acrosomal damage or premature acrosomal reaction, and therefore does not improve the dog sperm binding ability.(AU)

Avaliou-se o efeito da redução do cálcio livre no meio de congelamento, usando-se o quelante de cálcio etilenodiaminotetracético (EDTA) a 0,3% e 0,5%. Três cães machos sem raça definida foram submetidos à coleta de sêmen por manipulação digital (n=16). Cada ejaculado foi diluído em diluidor controle com TRIS-glicose - gema de ovo (TGE, controle), ou em diluidor TGE enriquecido com 0,3% (EDTA 0,3) ou 0,5% de EDTA (EDTA 0,5). A concentração de cálcio reduziu no meio EDTA 0,3, e todos os íons de cálcio foram quelados no meio EDTA 0,5. A adição do EDTA e a consequente quelação do cálcio não afetaram a morfologia espermática ou a integridade da membrana plasmática, no entanto, ao remover todo o cálcio do meio (EDTA 0,5), a motilidade espermática se reduziu (64,7% no TGE e 45% no EDTA 0,5; P<0,05). A integridade do acrossoma e a capacidade de ligação do espermatozoide não melhoraram com a quelação do cálcio. Apesar da influência da concentração de cálcio sobre a motilidade espermática após o descongelamento, a falha em prever a reação acrossomal prematura pode explicar por que a longevidade espermática não foi afetada pela remoção do cálcio no meio. Dessa forma, a remoção parcial ou total do cálcio, por meio da adição de EDTA, não é capaz de prevenir o dano no acrossoma ou a reação acrossomal prematura e, portanto, não aumenta a capacidade do espermatozoide de se ligar ao oócito.(AU)

Engineering tetravalent IgGs with enhanced agglutination potencies for trapping vigorously motile sperm in mucin matrix.

Multivalent antibodies such as sIgA can crosslink motile entities such as sperm and bacteria, creating agglomerates that are too large to permeate the dense mucin matrix in mucus, a process commonly referred to as immune exclusion. Unfortunately, sIgA remains challenging to produce in large quantities, and easily aggregates, which prevented their use in clinical applications. To develop sIgA-like tetravalent antibodies that are stable and can be easily produced in large quantities, we designed two IgGs possessing 4 identical Fab domains, with the Fabs arranged either in serial or in the diametrically opposite orientation. As a proof-of-concept, we engineered these tetravalent IgG constructs to bind a ubiquitous sperm antigen using a Fab previously isolated from an immune infertile woman. Both constructs possess at least 4-fold greater agglutination potency and induced much more rapid sperm agglutination than the parent IgG, while exhibiting comparable production yields and identical thermostability as the parent IgG. These tetravalent IgGs offer promise for non-hormonal contraception and underscores the multimerization of IgG as a promising strategy to enhance antibody effector functions based on immune exclusion.

Characteristics and Possible Role of Bovine Sperm Head-to-Head Agglutination.

Although sperm head-to-head agglutination has been reported in many mammalian species, the biological significance of this unique sperm-sperm interaction remains largely unknown. Here, we aimed to examine the functional characteristics of agglutinated bovine sperm to determine the possible role of sperm agglutination in the fertilization process. We initially examined temporal changes to the degree of head-to-head agglutination in culture, and found that bovine sperm agglutinated despite the lack of sperm agglutination inducers in medium. Sperm viability and motility were evaluated by SYBR14/PI and JC-1 staining, respectively, to identify the relationship between sperm agglutination and fertilizing ability. Agglutinated sperm had increased motility, viability, and intact mitochondrial function compared with unagglutinated sperm. Furthermore, we found that heparin significantly increased the percentage of unagglutinated sperm, but did not affect viability of both agglutinated and unagglutinated sperm, suggesting that sperm agglutination dictated the viability. In conclusion, agglutinated bovine sperm maintained viability and motility for a longer time than unagglutinated sperm. Thus, we propose that the head-to-head agglutination is a crucial sperm-sperm interaction to ensure the fertilizing ability of sperm.

Role of Lactobacillus in Female Infertility Via Modulating Sperm Agglutination and Immobilization.

Infertility has become a common problem in recent decades. The pathogenesis of infertility is variable, but microbiological factors account for a large proportion of it. Dysbiosis of vaginal microbiota is reportedly associated with female infertility, but the influence of normal vaginal microbiota on infertility is unclear. In this review, we summarize the physiological characteristics of the vaginal tract and vaginal microbiota communities. We mainly focus on the bacterial adherence of vaginal Lactobacillus species. Given that the adherent effect plays a crucial role in the colonization of bacteria, we hypothesize that the adherent effect of vaginal Lactobacillus may also influence the fertility of the host. We also analyze the agglutination and immobilization effects of other bacteria, especially Escherichia coli, on ejaculated spermatozoa, and speculate on the possible effects of normal vaginal microbiota on female fertility.

Evaluation of Sperm Impairing Factor from Serratia marcescens as Male Contraceptive in Mouse Model.

The present study was carried out to assess the contraceptive efficacy of sperm agglutinating factor (SAF) isolated from Serratia marcescens, in male Balb/c mice. Mice were administered via an intratesticular route with different concentrations of SAF, viz., 10, 50, 100, 200, or 400 µg, in the right testis only which served as a test while the left side served as control except otherwise stated. Mice were sacrificed on day 3, 7, 14, 21, 30, 45, 60, and 90 after administration, and results in terms of change in body weight, seminal parameters, tissue somatic indices (TSI), hematological parameters, serum level of testosterone, lipid peroxidation, and histology were studied. The body weight and TSI remained unaffected in all the experimental groups. In case of seminal parameters, the right testis treated with 10 µg, 50 µg, 100 µg, 200 µg, or 400 µg of SAF showed azoospermia up to day 7, 14, 21, 45, and 90, respectively. The hematological indices, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were found to be unaltered when the group receiving SAF (test) was compared with the groups receiving phosphate buffer saline (control) in the right testis; however, the treatment had a negative effect on the serum level of testosterone. It also affected the oxidative status of the right testis. Furthermore, histological studies revealed hypospermatogenesis and alterations in the seminiferous tubules which included intraepithelial vacuolation and exfoliation in the right side as compared to the left side. Thus, the results suggest that SAF (400 µg) causes suppression of spermatogenesis, without causing apparent toxic effects.

Contraceptive efficacy of sperm agglutinating factor from Staphylococcus warneri, isolated from the cervix of a woman with inexplicable infertility.

BACKGROUND: Voluntary control of fertility is of paramount importance to the modern society. But since the contraceptive methods available for women have their limitations such as urinary tract infections, allergies, cervical erosion and discomfort, a desperate need exists to develop safe methods. Vaginal contraceptives may be the answer to this problem, as these are the oldest ways of fertility regulation, practiced over the centuries. With minimal systemic involvement, these are also the safest. Natural substances blocking or impairing the sperm motility offer as valuable non-cytotoxic vaginal contraceptives. Antimicrobial peptides (AMPs) isolated from plants, animals and microorganisms are known to possess sperm immobilizing and spermicidal properties. Following this, in the quest for alternative means, we have cloned, over expressed and purified the recombinant sperm agglutinating factor (SAF) from Staphylococcus warneri, isolated from the cervix of a woman with unexplained infertility. METHODS: Genomic library of Staphylococcus warneri was generated in Escherichia coli using pSMART vector and screened for sperm agglutinating factor (SAF). The insert in sperm agglutinating transformant was sequenced and was found to express ribonucleotide-diphosphate reductase-α sub unit. The ORF was sub-cloned in pET28a vector, expressed and purified. The effect of rSAF on motility, viability, morphology, Mg++-dependent ATPase activity and acrosome status of human sperms was analyzed in vitro and contraceptive efficacy was evaluated in vivo in female BALB/c mice. RESULTS: The 80 kDa rSAF showed complete sperm agglutination, inhibited its Mg2+-ATPase activity, caused premature sperm acrosomal loss in vitro and mimicked the pattern in vivo showing 100% contraception in BALB/c mice resulting in prevention of pregnancy. The FITC labeled SAF was found to bind the entire surface of spermatozoa. Vaginal application and oral administration of rSAF to mice for 14 successive days did not demonstrate any significant change in vaginal cell morphology, organ weight and tissue histology of reproductive and non-reproductive organs and had no negative impact in the dermal and penile irritation tests. CONCLUSION: The Sperm Agglutinating Factor from Staphylococcus warneri, natural microflora of human cervix, showed extensive potential to be employed as a safe vaginal contraceptive.

Colonization of mouse vagina with Pseudomonas aeruginosa: A plausible explanation for infertility.

Little attention has been paid to the influence of asymptomatic colonizers of genital tract on female infertility. Albeit, a variety of uropathogens have been known to negatively alter sperm parameters in vitro, but their impact on female fertility outcome under in vivo conditions is not clearly established. Therefore, the present study was intended to investigate the effect of Pseudomonas aeruginosa on sperm parameters and to identify its role in female infertility. The strain of P. aeruginosa was found to reduce sperm motility, viability and sperm Mg++ATPase activity. It could also lead to premature acrosomal loss and induce morphological defect in spermatozoa. For fertility studies, female mice administered intravaginally with 104, 106, 108 cfu of P. aeruginosa for 10 consecutive days, were allowed to mate with proven breeder male on day 12. The results showed that group of mice receiving P. aeruginosa were rendered infertile whereas group receiving PBS showed abdominal distension, string of pearls and finally delivered pups at the end of gestation period. Further, no other clinical manifestation could be observed apparently, histologically or immunologically. Thus, it can be concluded that infertility in mice might be attributed to asymptomatic colonization of genital tract with sperm immobilizing P. aeruginosa.

Sperm agglutination: Prevalence and contributory factors.

Agglutination is a finding noted in semen analyses (SAs) that often causes confusion as to its significance. While some have attributed agglutination to antisperm antibodies (ASAs), there are other causes as well, such as genital tract infection and ascorbic acid deficiency. Additionally, it is known that patients with ASAs often have risk factors such as a history of scrotal trauma or surgery. Therefore, we sought to determine the prevalence of agglutination in our patient population and correlate it with these risk factors, regardless of the presence/absence of ASAs. A retrospective study was conducted on the SAs of men seen at a single academic Reproductive Center. Of the 1,095 SAs identified, 133 (12.1%) patients experienced agglutination (61.7% scant, 21.8% moderate and 16.5% excessive). Of patients who underwent multiple SAs, 24 (12.2%) showed variability. Furthermore, patients who underwent scrotal surgery carried 3.4 times the risk of agglutination (X2 p < 0.01) and 5.5 times the risk of variability (X2 p < 0.01) as compared to those patients without a history significant for scrotal surgery. Agglutination is a relatively common finding in men presenting to a reproductive clinic with little intrapatient variability. Scrotal surgery confers a higher risk of agglutination and variability.

The comparison of two different extenders for the improvement of large-scale sperm cryopreservation in common carp (Cyprinus carpio).

In our study, a traditionally used (Grayling, already used in cyprinid species) and a newly tested (Pike) extender was tested to avoid sperm agglutination phenomenon following thawing during carp sperm cryopreservation. A large-scale (elevated volume of sperm) freezing method in a controlled-rate freezer using 5 ml straw and 10 ml cryotube was also systematically established. In all experiments, the sperm cryopreserved in using Grayling extender (except only one sample) showed an agglutination phenomenon (damaged and intact cells adhered to each other) after thawing where Pike extender resulted the regular cell suspension. No significant difference was observed between the two cryopreserved groups (Pike and Grayling extender) in all motility parameters using the 0.5 ml straw and the polystyrene box. Similarly, motility parameters did not show a significant difference in the two frozen groups with the 5 ml straw, also in the polystyrene box. A significantly higher progressive motility (pMOT, Grayling: 54% ± 8%, Pike: 37% ± 5%), straight line velocity (VSL, Grayling: 50 ± 5 µm/s, Pike: 39 ± 4 µm/s) and beat cross frequency (BCF, Grayling: 20 ± 1 Hz, Pike: 17 ± 1 Hz) was observed in the case of the grayling extender by the 5 ml straw cryopreserved in a controlled-rate freezer (CRF) compare to the pike extender. A significantly higher VSL (Grayling: 45 ± 3 µm/s, Pike: 38 ± 4 µm/s) was observed by the grayling extender using the 10 ml cryotube than with the pike extender. Despite the randomly occurring differences in a few parameters, our new controlled freezing method using the newly tested Pike extender, the 5 ml straw or the 10 ml cryotube can be a good solution for the preservation of elevated volume of carp sperm.

Anti-sperm antibodies detection by a modified MAR test: Towards a better definition of its indications.

RESEARCH QUESTION: Anti-sperm antibodies (ASA) have been shown to reduce male fertility but consensus about the precise situations in which tests should be carried out are lacking. In infertility investigations, should the mixed antiglobulin reaction (MAR) test be a first-line test? Should it be carried out systematically before assisted reproductive technology (ART)? What are the risk factors for ASA? DESIGN: All infertile patients (n = 1364) were tested with SpermMar (modified MAR test) between July 2013 and June 2017. Intra-patient variability of the MAR test was also assesed by comparing two tests within the same year in selected patients (n = 101). RESULTS: The main factor that influenced the percentage of ASA was the presence or absence of sperm agglutination. In the presence of agglutinations, 27 out of 72 (37.5%) patients were positive for ASA compared with 33 out of 1292 (2.6%) in the absence of agglutinations (P < 0.0001). When one risk factor was present (spontaneous sperm agglutination, history of scrotal trauma or inguinal surgery), 33 out of 179 (18.44%) tests were positive for ASA (≥50% coated spermatozoa), whereas only 27 out of 1242 (2.2%) were positive when no risk factor was present (P < 0.0001). CONCLUSIONS: ASA detection should not be systematically recommended in investigations of fertility status and before ART but reserved for when sperm agglutination is found during conventional sperm examination, or if the patient has a history of scrotal trauma or has undergone inguinal surgery.

Melatonin affects the motility and adhesiveness of in vitro capacitated boar spermatozoa via a mechanism that does not depend on intracellular ROS levels.

This work sought to address the effects of melatonin during in vitro capacitation (IVC) and progesterone-induced acrosome exocytosis (IVAE) in boar spermatozoa. With this purpose, two different experiments were set. In the first one, IVC and IVAE were induced in the absence or presence of melatonin, which was added either at the start of IVC or upon triggering the IVAE with progesterone. Different parameters were evaluated, including intracellular levels of peroxides and superoxides, free cysteine radicals and distribution of specific lectins. While melatonin neither affected most capacitation-associated parameters nor IVAE, it dramatically decreased sperm motility, with a maximal effect at 5 µm. This effect was accompanied by a significant increase in the percentage of agglutinated spermatozoa, which was independent from noticeable changes in the distribution of lectins. Levels of free cysteine radicals were significantly lower in melatonin treatments than in the control after 4 h of incubation in capacitating medium. The second experiment evaluated the effects of melatonin on in vitro fertilising ability of boar spermatozoa. Spermatozoa previously subjected to IVC in the presence of 1 µm melatonin and used for in vitro fertilisation exhibited less ability to bind the zona pellucida (ZP) and higher percentages of monospermy. In conclusion, melatonin affects sperm motility and the stability of nucleoprotein structure and also modulates the ability of in vitro capacitated boar spermatozoa to bind the oocyte ZP. However, such effects do not seem to be related to either its antioxidant properties or changes in the sperm glycocalix.

A Unique Seminal Plasma Protein, Zona Pellucida 3-Like Protein, has Ca2+ -Dependent Sperm Agglutination Activity.

Identification of seminal proteins provides a means of investigating their roles. Despite their importance in the study of protein function, such as regulation of sperm motility, it is difficult to select candidates from the large number of proteins. Analyzing the rate of molecular evolution is a useful strategy for selecting candidates, and expressing the protein allows the examination of its function. In the present study, we investigated seminal plasma proteins of the cichlid Oreochromis mossambicus, which exhibits a unique mode of fertilization and a rapidly evolving gene that encodes a seminal plasma protein, zona-pellucida 3-like (ZP3-like), which does not belong to the same molecular family as other ZPs. Seminal plasma proteins of O. mossambicus were separated by two-dimensional electrophoresis, and 19 major proteins were identified by mass spectrometry (MALDI-Tof Mass). Because proteins that are under positive selection often impact sperm function, the rates of molecular evolution of these proteins were analyzed in terms of non-synonymous/synonymous substitutions (ω). Among the 19 proteins, positive selection was supported for five genes; functional assays were carried out on four of the proteins encoded by these genes. Of the four positively selected proteins, only ZP3-like protein agglutinated sperm in a dose- and Ca2+ -dependent manner. The other three proteins did not affect sperm motility. Because of the unique fertilization type, in which fertilization occurs in the buccal cavity, the need to retain sperm within the cavity during spawning, and the agglutination of sperm, which may be partly assisted by ZP3-like protein, may contribute to fertilization success. Fertilization in the buccal cavity may be related to its rapid molecular evolution.

Sperm agglutinating activity of Saccharomyces cerevisiae and Candida albicans as a potential causative factor of infertility in mice (Mus musculus)

@#<p style="text-align: justify;"><strong>BACKGROUND AND OBJECTIVE:</strong> Vaginal yeast infections in women are usually caused by Candida albicans and, to a lesser extent, by Saccharomyces cerevisiae. Studies on C. albicans have shown that it can cause sperm agglutination which can lead to lowered fertility. This study was conducted to compare the effect of S. cerevisiae and C. albicans on the fertility of ICR mouse (Mus musculus) through sperm agglutination.</p><p style="text-align: justify;"><strong>METHODOLOGY:</strong> Sperm agglutinating activity was examined by mixing different concentrations of S. cerevisiae (10, 10°, and 10 CFU/mL) and C. albicans (10", 10°, and 10 CFU/mL) separately with semen from male mice of ICR strain. Determination of the effect of S. cerevisiae and C. albicans on the fertility outcome of female mice was done by intravaginal inoculation of 20 uL of 104, 106, and 108 CFU/ml of the two yeast organisms and later allowed to mate.</p><p style="text-align: justify;"><strong>RESULTS AND CONCLUSION:</strong> The study showed a statistically significantly higher percent sperm agglutination by S. cerevisiae than C. albicans at 10* CFU/ml but no difference was observed at 10° and 10 CFU/ml. No significant difference was observed in the number of sperm per agglutinate between the two yeast species at a=0.05. The concentration that exhibited the highest percentage of agglutinated sperm is 10° CFU/mL for both yeast. The most frequent type of agglutination observed in S. cerevisiae is the mixed type, while head-to-head type is most frequent in C. albicans. Both yeasts were able to cause a decline in the number of births in mice starting at 10 CFU/ml. While sperm agglutination could be one of the reasons for the infertility observed in mice, there may be other processes, mechanisms, and/or activities that could contribute to such an outcome.</p>

In vitro characterisation of fresh and frozen sex-sorted bull spermatozoa.

This study sought to compare the in vitro characteristics of fresh and frozen non-sorted (NS) and sex-sorted (SS) bull spermatozoa. Experiment 1: Holstein-Friesian ejaculates (n=10 bulls) were split across four treatments and processed: (1) NS fresh at 3×106 spermatozoa, (2) X-SS frozen at 2×106 spermatozoa, (3) X-SS fresh at 2×106 spermatozoa and (4) X-SS fresh at 1×106 spermatozoa. NS frozen controls of 20×106 spermatozoa per straw were sourced from previously frozen ejaculates (n=3 bulls). Experiment 2: Aberdeen Angus ejaculates (n=4 bulls) were split across four treatments and processed as: (1) NS fresh 3×106 spermatozoa, (2) Y-SS fresh at 1×106 spermatozoa, (3) Y-SS fresh at 2×106 spermatozoa and (4) X-SS fresh at 2×106 spermatozoa. Controls were sourced as per Experiment 1. In vitro assessments for progressive linear motility, acrosomal status and oxidative stress were carried out on Days 1, 2 and 3 after sorting (Day 0=day of sorting. In both experiments SS fresh treatments had higher levels of agglutination in comparison to the NS fresh (P<0.001), NS frozen treatments had the greatest PLM (P<0.05) and NS spermatozoa exhibited higher levels of superoxide anion production compared with SS spermatozoa (P<0.05). Experiment 1 found both fresh and frozen SS treatments had higher levels of viable acrosome-intact spermatozoa compared with the NS frozen treatments (P<0.01).

Antisperm antibodies in repeat-breeding cows: Frequency, detection and validation of threshold levels employing sperm immobilization, sperm agglutination and immunoperoxidase assay.

Antisperm antibodies have been found in repeat-breeding(RB) cows, and those causing agglutination and/or immobilization of sperm are considered to be closely related to unexplained infertility. However, a standard protocol for identifying antisperm antibodies (ASA) in cattle is not validated. Therefore, an investigation was undertaken to evaluate sperm immobilization (SIT), sperm agglutination (SAT) and immunoperoxidase (IPT)assays for detection of ASA in serum and their respective threshold levels for confirmation. Animals (heifers, normally breeding, repeat-breeding and pregnant animals) that were free from IBR, brucellosis and uterine infections (screened by clinical examination) were included in the study. Sperm agglutinating, sperm immobilizing and antisperm antibodies evaluated by respective assay were significantly higher (p < .05) in RB cows compared to other groups. The SIT assay was able to identify 61% of RB caused by ASA, more than those employing SAT and IPT. Furthermore, a dilution rate of 1:5 and 1:80 (confirms 59.0 and 57.0% RB+ve)were sufficient to diagnose ASA by SAT and IPT, respectively. Results indicate the presence of __12.6% clumped spermatozoa and __ 2.6%(cut-off value) peroxidase-positive spermatozoa at 1:5 and 1:80 dilutions diagnosed with SAT and IPT, respectively, may be considered as repeaters arising out of ASA. Furthermore, study also showed the presence of lower incidence of ASA positivity in other groups of animals (heifer