Role of GPR55 receptor in bovine sperm capacitation.

Background: Endocannabinoids like anandamide (AEA), among other lipids, are recognized signaling molecules that participate in reproductive events.

Objectives: Our aims were to characterize orphan G protein-coupled receptor (GPR55) presence; investigate GPR55 activation by AEA and determine GPR55 role in the bovine sperm function.

Materials And Methods: GPR55 presence was assessed by immunocytochemistry.

Male reproductive biotechnologies in South American Camelids Part I: Semen collection, evaluation and handling.

This review describes the first steps necessary to apply any reproductive biotechnology in South American camelids (SAC) semen or sperm: sample collection, evaluation and handling. In camelids, the length and position adopted for mating and the site of semen deposition have conditioned semen collection methods. The advantages and disadvantages of available collection methods are summarized.

Effect of novel lyophilized extenders on stallion post-thaw sperm motility.

The aim of this study was to assess the effect of lyophilized freezing extenders, which can be stored at room temperature, on stallion post-thaw sperm total motility (TM). Ejaculates of 28 stallions were frozen with four different extenders: two commercial freezing extenders offered worldwide and two novel lyophilized extenders (STAR and MX3), and two different cryopreservation protocols (CP1 with an equilibration period of 20 min. and CP2 with an equilibration period of 60 min.

Effect of bicarbonate and polyvinyl alcohol on in vitro capacitation and fertilization ability of cryopreserved equine spermatozoa.

Background: Factors contributing to the limited success of in vitro fertilization in horses remain to be studied. In this work, we elucidated the effect of different essential capacitation media components, bicarbonate, and bovine serum albumin or polyvinyl-alcohol, and the incubation microenvironment on sperm parameters associated with capacitation, acrosome reaction, and their ability to activate oocytes via heterologous intracytoplasmic spermatozoa injection in equine cryopreserved spermatozoa.

Methods: Frozen-thawed spermatozoa underwent incubation at different time intervals in either Tyrode's albumin lactate pyruvate medium (non-capacitating; NC) or Tyrode's albumin lactate pyruvate supplemented with bicarbonate, bicarbonate and polyvinyl-alcohol, bicarbonate and bovine serum albumin, polyvinyl-alcohol and bovine serum albumin alone.

Evaluation of equine semen frozen in extenders free of egg yolk using two different freezing curves.

A chemically defined cryopreservation extender that maintains seminal parameters is relevant. Fifteen ejaculates from 5 stallions (n= 5; r=3) were diluted in 5 extenders: 1) EDTA-glucose based extender with egg-yolk and dimethylformamide (EY); 2) commercial equine extender (CE); 3) CE with dimethylformamide (CE-3); 4) bovine commercial extender with liposomes (OP); 5) bovine commercial extender with soybean lecithin (BIO), and frozen using a slow and a rapid temperature descent curve. Post-thaw evaluations were: sperm kinematic parameters, viability and acrosome status, membrane lipoperoxidation and DNA fragmentation.

Comparison of different cryoprotectants for freezing donkey (Equus asinus) semen.

The aim of this study was to evaluate two cryoprotectants, dimethylformamide (DMF) and methylformamide (MF) in two concentrations (5 and 7 %) in vitro in donkey semen using a rapid freezing technique and the effect on pregnancy rates in mares. Twenty-four ejaculates from 8 jacks (n = 8; r = 3) were divided into 4 extenders: BotuSemen Gold with 5 % or 7 % MF and 5 % or 7 % DMF, all containing 11 % lactose, 20 % egg-yolk and 0.5 % Equex.

Effect of storage and single layer centrifugation before cryopreservation on stallion sperm cryosurvival.

The objectives of this study were to evaluate the effect of a short, cooled storage before cryopreservation on sperm progressive motility (PM) and compare the effect of different centrifugation methods on post-thaw PM of stored samples. Semen was diluted in chilling extender and aliquoted in 6 protocols: i) Standard centrifugation (SC) followed by freezing; ii) Single Layer Centrifugation (SLC) followed by freezing; iii) Storage for 8 h/5 °C before SC; iv) Storage for 8 h/5 °C before SLC; v) Storage for 8 h/15 °C before SC; and vi) Storage for 8 h/15 °C before SLC. PM was assessed before centrifugation, after centrifugation, and post-thawing.

The ability of donkey sperm to induce oocyte activation and mule embryo development after ICSI.

Members of the Equus genus exhibit a fascinating capacity for hybridization, giving rise to healthy offspring. Mules, resulting from the mating of a mare with a jack, represent the most prevalent equid hybrid, serving diverse roles in our society. While in vitro embryo production, particularly through Intracytoplasmic Sperm Injection (ICSI), has rapidly gained significance in domestic horses, the in vitro production in other equids remains largely unexplored.

Glass wool column filtration for stallion sperm selection: A comparative analysis with the single-layer colloid centrifugation.

Glass wool column filtration (GWCF) selects human, bull, boar, dog and buffalo spermatozoa, but reports in the horse are scarce. Single-layer colloid centrifugation with Androcoll-E™ is currently the standard procedure to select good-quality equine sperm. This study was designed to assess GWCF (50 and 75 mg columns; GWCF-50 and GWCF-75, respectively) efficacy to select good-quality sperm from fresh and frozen-thawed equine semen, and to compare its performance with Androcoll-E™ colloid centrifugation.

Effect of early administration of progesterone on the function of the corpus luteum of llamas.

The aim of the present study was to evaluate if early administration of progesterone immediately after ovulation affects corpus luteum lifespan in llamas. Female llamas (n = 16) were induced to ovulate by Buserelin injection in the presence of an ovulatory follicle (Day 0). On Day 2, ovulation was confirmed and animals were randomly divided into two groups: treated animals (n = 8) received an intravaginal device containing 0.

Identification of coronaviruses in bats and rodents in northern and central Argentina.

Due to the present pandemic situation and the many animal species that are epidemiologically involved, there has been a surge of renewed interest in investigating the coronavirus (CoV) population circulating in wildlife, especially bats and rodents, which are potential reservoirs of new human pathogens. In Argentina, information about the viruses present in these mammals is very limited. To investigate the presence of coronaviruses in this country, we obtained 457 samples from hematophagous, insectivorous, and frugivorous bats and rodents from two regions of Argentina.

Effect of hCG administration on Day 7 post-mating on accessory corpus luteum development and progesterone concentration in llamas.

A high embryo loss rate has been reported in llamas. As strategies that lead to an increase in plasma progesterone (P4) concentration might improve fertility, the aim of the present study was to evaluate if the administration of hCG on Day 7 post-mating is useful to develop an accessory corpus luteum (CL), increasing plasma P4 concentration. Twenty (n = 20) female llamas, ranging between 5 and 10 years of age and four (n = 4) males of proven fertility, ranging between 8 and 10 years of age were included in the study.

Detection of lipid peroxidation in dog spermatozoa with the fluorescent dye C11-BODIPY.

C11-BODIPY is a fluorescent probe that has been successfully used to evaluate lipid peroxidation in different species, but it has not been completely studied in the dog. Thus, the aim of the present study was to assess lipid peroxidation of dog spermatozoa using C11-BODIPY and compare different positive controls of the technique. Twenty-four ejaculates were collected from 8 adult male dogs.

Use of dimethylformamide to cryopreserve alpaca semen previously incubated with collagenase.

The objective of this study was to evaluate the effect of collagenase and two final dimethylformamide (DMF) concentrations (4% and 7%) on alpaca frozen-thawed sperm quality. A total of 25 ejaculates from 5 alpaca were obtained using electroejaculation. Each individual ejaculate was evaluated and then diluted 4:1 in a solution of 1 mg/ml collagenase in HEPES-TALP medium and incubated for 4 min at 37°C.

Cryopreservation of llama semen using a combination of permeable cryoprotectants.

Semen cryopreservation is not available for massive use in South American Camelids (SACs) due to the lack of an efficient protocol and the low pregnancy rates obtained with artificial insemination (AI). The use of a single cryoprotectant (CP) is commonly used in SACs frozen semen. The objective of the study was to evaluate the combined cryoprotective capacity of two permeable CPs at different stages of the cryopreservation protocol in llama semen.

Hormone Concentrations and Semen Parameters in Criollo Breed Stallions Under Training.

The stress associated with training may reduce reproductive efficiency in Criollo stallions. The objective of this study was to compare semen quality and hormone concentrations in Criollo stallions under training or under regular field conditions. Criollo breed stallions (n = 18) were evaluated during the spring.

Characteristics of follicular dynamics and reproductive hormone profiles during oestrous cycles of jennies over an entire year.

Although donkeys have been domesticated for over 6,000 years, limited information is available concerning their reproductive physiology, especially under intensive rearing conditions. The aims of this experiment were to study follicular dynamics and reproductive hormone variation in jennies during the inter-ovulatory interval in different seasons. A total of 12 continuous cycles of six Dezhou Black (DB) donkey jennies were examined in four different seasons.

Uterine and Corpus Luteum Blood Flow Evaluation Prior to Uterine Flushing in Llama Embryo Donors.

The aim of this study was to assess the uterine blood flow (UBF) and corpus luteum blood flow (CLBF) in llamas 8 days post-mating, using color-Doppler ultrasonography (CDU), to determine the possible relationship between vascularization and the presence of an embryo. Adult females ( = 25) were used to monitor ovarian dynamics by palpation and transrectal ultrasonography until detection of a ≥6 mm growing follicle. Females were randomly assigned to one of two groups: Group I ( = 19), were mated and ovulation was induced by a single dose of buserelin (GnRH analog) that same day (Day 0); and Group II ( = 6), only ovulation was induced (control).

Development of a GnRH-PGF Based Synchronization and Superstimulation Protocol for Fixed-Time Mating in Llama Embryo Donors.

The aim of the present study was to evaluate the application of a GnRH-PGF based synchronization and superstimulation protocol for fixed-time natural mating in llama embryo donors. All females ( = 8) received 8 μg IM of GnRH analog (GnRHa; buserelin) on day 0, regardless of follicular status. After eight days, another GnRHa dose was administered followed by 250 μg IM PGF (cloprostenol).

Plasma IGF1 and 17β-Estradiol Concentrations During the Follicular Wave in Llamas.

The aim of this study was to characterize the temporal association between follicular waves and circulating concentrations of 17β-estradiol (E2) and IGF1 in llamas. Follicular waves could be clearly divided in three phases: growth, plateau and regression; with a mean duration of 18.8 ± 0.

Cyclic AMP efflux through MRP4 regulates actin dynamics signalling pathway and sperm motility in bovines.

Previously we demonstrated that multidrug resistance-associated protein 4 transporter (MRP4) mediates cAMP efflux in bovine spermatozoa and that extracellular cAMP (ecAMP) triggers events associated to capacitation. Here, we deepen the study of the role of MRP4 in bovine sperm function by using MK571, an MRP4 inhibitor. The incubation of spermatozoa with MK571 during 45 min inhibited capacitation-associated events.

New protocol to separate llama sperm without enzymatic treatment using Androcoll-E.

The objective of this study was to design a protocol to separate spermatozoa from seminal plasma of raw llama semen without prior enzymatic treatment using a single-layer centrifugation with Androcoll-E (AE). Two experiments were performed: (a) samples were divided into three aliquots (1 ml) that were deposited on the top of 4, 5 or 6 ml of AE and were centrifuged at 800g for 20 min and (b) samples were divided into two aliquots (1 ml) that were deposited on the top of 4 ml of AE and were centrifuged at 600g or 1,000g for 20 min. Columns of 5 and 6 ml of AE showed a total sperm motility (TM) significantly lower, while in the 4 ml column, this parameter was not different from the TM of samples before the AE treatment.

Incubation of frozen-thawed llama sperm with seminal plasma.

Seminal plasma is intimately connected to sperm physiology and particularly in South American Camelids, has demonstrated to be involved in multiple physiological reproductive events. Different percentages of seminal plasma (0%, 10% and 50%) were added to thawed llama semen samples with the objective of evaluating the interaction with cryopreserved sperm over time (0, 1.5 and 3 hr at 37°C).

Corpus luteum vascularization during the maternal recognition of pregnancy in llamas (Lama glama).

The aim of this study was to characterize corpus luteum vascularization and its association with plasma progesterone concentration in early stages of pregnancy, when maternal recognition of pregnancy is expected to occur. In all animals, both plasma progesterone concentration and corpus luteum vascularization increased from Day 6 to Day 8 post-mating and afterwards in non-pregnant llamas they started to decrease to reach basal levels around Days 12 to 14 post-mating, while in pregnant animals, both variables remained elevated until the end of the study. A lineal positive relationship between corpus luteum vascularization and plasma progesterone concentration was observed in pregnant (r  = .