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Theriogenology.
Publisher:
Geron-X.. [New York, N.Y.?] : Elsevier
Frequency: Sixteen no. a year
Country: United States
Language: English
Start Year:1974 -
ISSN:
0093-691X (Print)
1879-3231 (Electronic)
0093-691X (Linking)
1879-3231 (Electronic)
0093-691X (Linking)
Impact Factor
2.8
2022
| NLM ID: | 0421510 |
| (OCoLC): | 02504829 |
| (DNLM): | T08780000(s) |
| Coden: | THGNBO |
| Classification: | W1 TH677K |
Expression of anti-Müllerian hormone, cyclin-dependent kinase inhibitor (CDKN1B), androgen receptor, and connexin 43 in equine testes during puberty. Sertoli cells are essential in development of a functional testis. During puberty, Sertoli cell maturation can be characterized by a number of markers, including anti-Müllerian hormone (AMH) and its receptor (AMHR2), androgen receptor (AR), cyclin-dependent kinase inhibitor (CDKN1B), and connexin 43 (Cx43). In the present study, immunohistochemistry (IHC) and real-time quantitative polymerase chain reaction (RT-qPCR) were used to characterize changes in expression of AMH, AMHR2, AR, CDKN1B, and Cx43 in prepubertal, postpubertal, and adult equine testes. During puberty, AMH expression decrease...
Effect of centrifugal fractionation protocols on quality and recovery rate of equine sperm. Centrifugal fractionation of semen is commonly done to improve quality of human semen in assisted-reproduction laboratories, allowing sperm separation based on their isopycnic points. Sperm with morphologic abnormalities are often more buoyant, promoting their retention above defined density media, with structurally normal sperm passing through the media following centrifugation. Three experiments were conducted to evaluate the effects of density-medium type, centrifuge-tube size, sperm number, and density-medium volume (column height) on stallion sperm quality and recovery rate in sperm pelle...
Nucleolar organizer regions (NORs) distribution and behavior in spermatozoa and meiotic cells of the horse (Equus caballus). Nucleolar organizing regions (NORs) containing rDNA gene clusters have been assigned to the equine autosomes ECA1, ECA28, and ECA31. Active NORs (Ag-NORs) are associated with argyrophilic proteins, which allow them to be readily identified using silver staining techniques. Fluorescence in situ hybridization (FISH) for rDNA can also be used to visualize all NOR clusters in the nucleus, regardless of whether they are active or inactive. The present study analyzed the distribution and behavior of equine Ag-NOR and NOR clusters in horse spermatozoa and during male meiosis by FISH and silver staini...
Equine fetal sex determination using circulating cell-free fetal DNA (ccffDNA). In this study, polymerase chain reaction (PCR) reamplification of the first PCR product (2nd-PCR) and a qPCR assay were used to detect the sex determining region Y (SRY) gene from circulating cell-free fetal DNA (ccffDNA) in blood plasma of pregnant mares to determine fetal sex. The ccffDNA was isolated from plasma of 20 Thoroughbred mares (5-13 y old) in the final 3 mo of pregnancy (fetal sex was verified after foaling). For controls, plasma from two non-pregnant mares and two virgin mares were used, in addition to the non-template control. The 182 bp nucleotide sequence corresponding to the ...
Ultrasound characteristics of experimentally induced luteinized unruptured follicles (LUF) and naturally occurring hemorrhagic anovulatory follicles (HAF) in the mare. The development of hemorrhagic anovulatory follicles (HAF) involves luteinization and hemorrhage of the follicle. This is observed on ultrasound as an increase in the echogenicity of the granulosa layer and formation of echoic particles in the antrum. The inhibition of prostaglandin synthesis with flunixin meglumine (FM) during the periovulatory period induces ovulatory failure with development of luteinized unruptured follicles (LUF). These two types of anovulatory follicles appear to share similar ultrasound features but they have not been compared critically. The following endpoints: follic...
Ultrasonographic features of the mule embryo, fetus and fetal-placental unit. The aim of this study was to establish baseline ultrasound data concerning the mule conceptus during gestation. Ten multiparous Trotter mares were artificially inseminated with chilled semen from an Amiatino jack donkey. Daily transrectal ultrasonography was carried out from the day of ovulation until Day 50 of gestation to determine the following: first detection of the embryonic vesicle (EV), mobility phase, EV diameter, day of EV fixation, changes in EV shape, date of yolk sac regression and embryo crown-rump length. Monthly ultrasonic assessments from Day 50 of gestation to term were carri...
The risk of introduction of equine infectious anemia virus into USA via cloned horse embryos imported from Canada. Deriving horse oocytes in the USA is hampered by the lack of abattoirs processing horse carcasses which could provide abundant quantities of ovaries from slaughtered mares. Therefore, several cloning industries in the USA are attempting to import cloned horse embryos from Canada. Like any agricultural commodity, cloned embryos pose a risk of introduction of exotic animal diseases into the importing country. Under such circumstances, risk assessment could provide an objective, transparent, and internationally accepted means for evaluating the risk. This quantitative risk assessment (QRA) was in...
Uterine artery blood flow remains unchanged in pregnant mares in response to short-term administration of pentoxifylline. The objective of this study was to use Doppler ultrasound technology to determine whether pentoxifylline administration increased uterine blood flow in normal pregnant pony mares. Thirteen pregnant pony mares between 18 and 190 d of gestation (mean ± SEM, 101 ± 55) were utilized for the study during two trial periods. In each trial, pentoxifylline (17 mg/kg by mouth every 12h, diluted in syrup) was administered to half of the mares for 3 d, while the other mares were treated with syrup only. Doppler measurements were obtained from the right and left uterine arteries from each mare for 2 d pr...
Liposomes as an alternative to egg yolk in stallion freezing extender. Egg yolk is normally used as a protective agent to freeze semen of equine and other species. However, addition of egg yolk in extenders is not without disadvantages and the demand to find cryoprotective alternatives is strong. The objective of this study was to test the cryoprotective capacities of liposomes composed of egg yolk phospholipids. Two experiments were conducted: 1) the first to determine the optimal composition and concentration of liposomes to preserve post-thaw motility and membrane integrity of spermatozoa; 2) the second to assess in vivo the cryoprotective capacities of these ...
Temporal relationships of a pulse of prolactin (PRL) to a pulse of a metabolite of PGF2α in mares. Hourly blood samples were collected from 10 mares during 24 h of each of the preluteolytic, luteolytic, and postluteolytic periods. The autocorrelation function of the R program was used to detect pulse rhythmicity, and the intra-assay CV was used to locate and characterize pulses of prolactin (PRL) and a metabolite of prostaglandin F2α (PGFM). Rhythmicity of PRL and PGFM concentrations was detected in 67% and 89% of mares, respectively. Combined for the three periods (no difference among periods), the PRL pulses were 5.2±0.4 h (mean±SEM) at the base, 7.5±1.5 h between nadirs of adjacent p...
Comparison of the cytobrush, cottonswab, and low-volume uterine flush techniques to evaluate endometrial cytology for diagnosing endometritis in chronically infertile mares. Endometritis is the most important cause of infertility in barren mares. The quick method of endometrial cytology (EC) has a relatively high reliability in diagnosing endometrial inflammation in the mare. For reliable cytological results, a collection technique that yields many well-preserved cells representative of a large uterine surface area without causing harm to the reproductive tract is required. The aim of the study was to compare three usually employed techniques for collection of endometrial and inflammatory cells (guarded cotton swab, uterine lavage, and cytobrush) in chronically in...
Morpho-functional studies regarding the fertility prognosis of mares suffering from equine endometrosis. The aim of the present study was to characterize the morpho-functional features of endometrosis in barren and foaling mares, using both conventional histopathological and immunohistochemical methods. Endometrial biopsy samples were collected during the physiological breeding season from 159 estrous, clinically healthy mares (mean age 12 years), and the quality and degree of endometrosis was histomorphologically defined. The mares were bred and those that foaled were put in the foaling group whereas those that did not foal were placed in the barren group. Foaling mares were then compared with b...
Relationship between progesterone, oestrone sulphate and cortisol and the components of renin angiotensin aldosterone system in Spanish purebred broodmares during pregnancy. The coordinated interaction of the components of the renin angiotensin aldosterone system (RAAS) with reproductive hormones such as progesterone, oestrogens and cortisol during pregnancy has been widely reported to play a vital role in foetal and placental development in various species, significantly influencing the proper achievement of pregnancy and foetal viability at birth. These interactions have not yet been clarified in mares. Thus, the purpose of the present research was to analyse the relationship between cortisol (CORT), progesterone (P4) and oestrone sulphate (OESTRONE), and the co...
Dissecting the molecular damage to stallion spermatozoa: the way to improve current cryopreservation protocols? We review recent developments in the technology of freezing stallion sperm, paying special attention to the molecular lesions that spermatozoa suffer during freezing and thawing, such as osmotic stress, oxidative damage, and apoptotic changes. We also discuss the applicability of colloidal centrifugation in stallion sperm cryobiology. Increased knowledge about the molecular injuries that occur during cryopreservation may lead to improved protective techniques and thus to further improvements in fertility in the current decade.
Cryopreservation of immature equine oocytes, comparing a solid surface vitrification process with open pulled straws and the use of a synthetic ice blocker. The objective was to evaluate the effect of three cryopreservation methods on the in vitro maturation (IVM) and membrane integrity (MIn) of immature equine oocytes. An open pulled straw (OPS) method, a novel solid surface vitrification (SSV) process, and the addition of a synthetic ice blocker were evaluated. Compared with the control group (N=269), the OPS (N=159) and the SSV (N=202) cryopreservation methods decreased both IVM (50.9 vs. 13.3 and 9.4%, respectively; P<0.001) and MIn (76.6 vs. 31.1 and 33.7%; P<0.001) of immature equine oocytes. However, inclusion of 0.1% ice blocker in t...
G6PDH-activity in equine oocytes correlates with morphology, expression of candidate genes for viability, and preimplantative in vitro development. Efficiencies for in vitro production of equine embryos are still low due to highly variable developmental competences of equine immature oocytes. In contrast to the equine, in vitro developmental competence of immature oocytes has been predicted successfully by the activity of glucose-6-phosphate dehydrogenase (G6PDH) indicated by brilliant cresyl blue (BCB) dye in a range of different species. Therefore, the aim of the present study was to test the association between G6PDH activity in equine oocytes with: (1) cumulus morphology and oocyte properties in terms of diameter and volume; (2) matur...
Permeability of the equine embryonic capsule to ethylene glycol and glycerol in vitro. Poor survival of cryopreservation by equine expanded blastocysts may involve low penetration of the embryonic capsule by cryoprotective agents (CPAs). This study characterized the permeation and accumulation rates of the CPAs ethylene glycol (EG) and glycerol (GLY) across isolated capsule in vitro, using a dual-chambered Valia-Chien permeation apparatus. Pieces of Days 14 to 18 ± 1 capsules separated media in the "donor" chamber containing either 1.5 M EG (n = 6), 0.74 M EG (n = 5), 0.87 M GLY (n = 7), or 0.15 M NaCl (saline, SAL) (n = 6), from the "recipient" chamber. Concentrations of CPA, ...
Biological and clinical significance of anti-Müllerian hormone determination in blood serum of the mare. Anti-Müllerian hormone (AMH), a member of the transforming growth factor β superfamily of growth and differentiation factors, is expressed in granulosa cells of preantral and small antral ovarian follicles. In humans, AMH appeared to regulate recruitment and growth of small ovarian follicles. Furthermore, circulating AMH concentrations were elevated in women with granulosa-cell tumors (GCT). In the horse, GCTs are the most common tumor of the ovary, and a variety of endocrine assays have been used to diagnose presumptive GCTs. The objectives of the present study were to validate a heterologo...
Processing stored stallion semen doses by Single Layer Centrifugation. The purpose of this study was to determine if the quality of stored stallion semen doses could be enhanced by the scaled-up version of Single Layer Centrifugation using Androcoll-E-Large. Three semen doses from each of fifteen stallions were transported overnight to the Swedish University of Agricultural Sciences (SLU) for processing 24 h after semen collection. Sperm quality in the resulting SLC-selected samples was significantly improved compared to the uncentrifuged samples: mean progressive motility was increased by 8% on the day of processing (P < 0.001) and by 13% after 24 h cold stor...
Effect of pentoxifylline treatment on testicular perfusion and semen quality in Miniature horse stallions. The objective was to investigate the effects of pentoxifylline (PTX) on testicular perfusion and sperm production in stallions. In a preliminary study, six mature Miniature horse stallions were given 0, 8.5, or 17.0 mg/kg of PTX orally, twice daily, for 3 d. Total Arterial Blood Flow Rate (TABFR) was higher (P < 0.05) in all treated versus control stallions during and after treatment. Two months later (during the fall and winter), the same stallions received either 0 or 17 mg/kg of PTX orally, twice daily for 60 d. Resistance and pulsatility indices (RI and PI, respectively) decreased in PT...
Evidence-based medicine in bovine, equine and canine reproduction: quality of current literature. The objective was to evaluate deficits and differences of published literature on reproduction in cattle, horses, and dogs. A literature search was conducted in the databases Medline and Veterinary Science. Approximately five times more articles on clinical bovine reproduction (n = 25 910) were found compared to canine (n = 5 015) and equine (n = 5 090) reproduction. For the evaluation of the literature, a checklist was used. A subset of 600 articles published between 1999 and 2008 was randomly selected. After applying exclusion criteria, a total of 268 trials (86 for cattle, 99 for horses, an...
Characteristics of the equine embryo and fetus from days 15 to 107 of pregnancy. In spite of numerous, substantial advances in equine reproduction, many stages of embryonic and fetal morphological development are poorly understood, with no apparent single source of comprehensive information. Hence, the objective of the present study was to provide a complete macroscopic and microscopic description of the equine embryo/fetus at various gestational ages. Thirty-four embryos/fetuses were aged based on their crown rump length (CRL), and submitted to macroscopic description, biometry, light and scanning microscopy, as well as the alizarin technique. All observed developmental c...
Effect of method and clinician on stallion sperm morphology evaluation. The objective of this study was to determine the effects of method and clinician on stallion sperm morphology evaluation. Five clinicians evaluated 60 semen samples using wet-mount preparations with phase-contrast, eosin/nigrosin-stained semen smears, and Papanicolaou-stained semen smears. There were significant differences among methods for all sperm morphology categories and most intra-class correlation coefficients were only fair to moderate. The use of wet-mount preparations facilitated detection of acrosome defects, nuclear vacuoles, and cytoplasmic droplets when compared to stained smear...
In vitro maturation and artificial activation of donkey oocytes. Three media were evaluated for their ability to support in vitro maturation of donkey (Equus asinus) oocytes and their development after parthenogenetic activation. The basal medium for Medium 1 (M1) and Medium 2 (M2) was M199 and DMEM/F12 respectively, whereas, Medium 3 (M3) consisted of equal parts (v/v) of M199 and DMEM/F12. All three media were supplemented with 10% (v/v) fetal calf serum, 0.01 units/mL porcine FSH, 0.01 units/mL equine LH, 200 ng/mL insulin-like growth factor 1(IGF-I), 10 μl/mL insulin-transferrin-selenium (ITS), 0.1 mg/mL taurine, 0.1 mg/mL L-cysteine, 0.05 mg/mL L-glut...
Two-dimensional polyacrylamide gel electrophoresis of equine seminal plasma proteins and their relation with semen freezability. The objective was to evaluate protein profiles of equine seminal plasma using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and to determine whether any of these proteins were related to semen freezability. Seminal plasma was collected from 10 stallions, of high and low semen freezability, housed at the State Stud of Lower Saxony, and routinely used in AI programs. Twenty-five protein spots were identified from the two-dimensional gel (12%), seven of which were present in all samples (all proteins were identified by MALDI-MS). Matrix-assisted laser desorption/ionization mass spe...
Presence and distribution of fungi and bacteria in the reproductive tract of healthy stallions. A saprophytic bacterial flora is present on the penis and the distal part of the urethra of stallions. Little is known about the fungal flora of their reproductive tract. As micro organisms play an important role in mares fertility, the aim of the study was to describe the distribution of fungi and bacteria in the normal genital apparatus of stallions. The microbic flora of the reproductive tract of 11 healthy, fertile stallions was evaluated, collecting samples from 5 different locations: urethral fossa, penis/internal lamina of the prepuce, urethra pre- and post-ejaculation, and semen. For f...
Exercise affects both ovarian follicular dynamics and hormone concentrations in mares. The objectives were to evaluate the effects of exercise on ovarian folliculogenesis and related hormones in mares. Mares (n = 11) were randomly assigned into a control (non-exercised) or treatment (exercised) group. Treatment mares (n = 5) were moderately exercised for 30 min, 6 d/wk. All mares underwent daily transrectal ultrasonographic examinations and ovarian follicles > 6 mm were measured. Blood samples were collected during the first (Cycle 1) and last (Cycle 4) cycle, and serum concentrations of cortisol, LH, and FSH were determined. Mean cortisol concentrations were elevated (P <...
Relationship between sperm motility, morphology and the fertility of stallions. Sperm quality has an important role in determining fertility. Although there have been numerous studies to document the relationship between sperm quality and fertility, the methods of determining this association and conclusions vary. In the present study, computer-assisted sperm analysis (CASA) was used for evaluation of sperm motility, and differential interference contrast (DIC) microscopy was used for evaluating sperm morphologic features of breeding stallions. Fertility was measured using three endpoints: seasonal pregnancy rate (PR), percent pregnant/cycle (PC), and percent pregnant/fir...
Osmotic properties of stallion sperm subpopulations determined by simultaneous assessment of cell volume and viability. The aim of this study was to determine the osmotic tolerance limits of stallion sperm as well as the osmotic behavior of different sperm subpopulations, including viable and non-viable cells as well as viable cells of different average sizes. A flow cytometric approach was used for simultaneous assessment of cell volume and permeability of the plasma membrane for the fluorescent dye propidium iodide while exposing the cells to media with different solute concentrations. Equine spermatozoa have limited osmotic tolerance limits: exposure to hypotonic conditions below approximately 240 mOsm kg(-1...
Effect of cryopreservation protocol on postthaw characteristics of stallion sperm. Three ejaculates from each of eight stallions were subjected to cryopreservation in a milk/egg yolk-based freezing extender or an egg yolk-based freezing extender. Semen was exposed to a fast prefreeze cooling rate (FAST; semen immediately subjected to cryopreservation) or a slow prefreeze cooling rate (SLOW; semen pre-cooled at a controlled rate for 80 min prior to cryopreservation). Postthaw semen was diluted in initial freezing medium (FM) or INRA 96 (IMV Technologies, L'Aigle, France) prior to analysis of 10 experimental end points: total motility (MOT; %), progressive motility (PMOT; %), ...
