Reproduction, fertility, and development.
Publisher:
Commonwealth Scientific and Industrial Research Organisation,
Frequency: Eight no. a year, 1996-
Country: Australia
Language: English
Author(s):
CSIRO (Australia), Fertility Society of Australia., Australian Academy of Science., Australian Society for Reproductive Biology., Society for Reproductive Biology.
Start Year:1989 -
ISSN:
1031-3613 (Print)
1031-3613 (Linking)
1031-3613 (Linking)
Impact Factor
1.9
| NLM ID: | 8907465 |
| (DNLM): | SR0065297(s) |
| (OCoLC): | 19505713 |
| Coden: | RFDEEH |
| Classification: | W1 RE213KK |
Advancements in microfluidic and electrophoretic techniques for stallion sperm isolation. Context Equine reproductive technologies are crucial for overcoming challenges in natural fertilisation, particularly in sub-fertile stallions and breeding programs focused on genetic conservation and performance enhancement. Assisted reproductive technologies (ARTs), such as artificial insemination (AI), intracytoplasmic sperm injection (ICSI), and in vitro fertilisation (IVF), improve fertility outcomes and enable breeding across geographical distances. Aims This review examines sperm isolation techniques used in ART, evaluating their efficacy, limitations, and potential to enhance reproduct...
The future of equine semen analysis. We are currently experiencing a period of rapid advancement in various areas of science and technology. The integration of high throughput 'omics' techniques with advanced biostatistics, and the help of artificial intelligence, is significantly impacting our understanding of sperm biology. These advances will have an appreciable impact on the practice of reproductive medicine in horses. This article provides a brief overview of recent advances in the field of spermatology and how they are changing assessment of sperm quality. This article is written from the authors' perspective, using the sta...
Equine in vitro produced blastocysts: relationship of embryo morphology, stage and speed of development to foaling rate. Information on factors associated with developmental competence of equine in vitro -produced (IVP) blastocysts is lacking. Objective: To determine the relationships of stage, grade, day of development, and specific morphological parameters of equine IVP blastocysts, to pregnancy and foaling rates. Methods: Photomicrographs of 316 IVP embryos with known pregnancy outcomes were scrutinised individually by four observers. Inter-observer variation was assessed, and pregnancy outcome evaluated in relation to day of blastocyst development and assigned grade and stage. Individual component analysis w...
Lethal variants of equine pregnancy: is it the placenta or foetus leading the conceptus in the wrong direction? Embryonic and foetal loss remain one of the greatest challenges in equine reproductive health with 5-10% of established day 15 pregnancies and a further 5-10% of day 70 pregnancies failing to produce a viable foal. The underlying reason for these losses is variable but ultimately most cases will be attributed to pathologies of the environment of the developing embryo and later foetus, or a defect intrinsic to the embryo itself that leads to lethality at any stage of gestation right up to birth. Historically, much research has focused on the maternal endometrium, endocrine and immune responses ...
Female age and parity in horses: how and why does it matter? Although puberty can occur as early as 14-15months of age, depending on breed and use, the reproductive career of mares may continue to advanced ages. Once mares are used as broodmares, they will usually produce foals once a year until they become unfertile, and their productivity can be enhanced and/or prolonged through embryo technologies. There is a general consensus that old mares are less fertile, but maternal age and parity are confounding factors because nulliparous mares are usually younger and older mares are multiparous in most studies. This review shows that age critically affects c...
Equine early pregnancy endocrine profiles and ipsilateral endometrial immune cell, gene expression and protein localisation response. We investigated the early effects of the equine embryo on maternal serum concentrations of insulin-like growth factor 1 (IGF1), leptin and adiponectin, uterine immune cells and genes and proteins related to embryo development and the maintenance of pregnancy. Ipsilateral endometrial expression was assessed on Days 7 and 13 after ovulation for the following transcripts: oestrogen receptor ERα (ESR1), progesterone receptor (PGR), progestin and adipoQ receptor family member 5 (PAQR5), oxytocin receptor (OXTR), prostaglandin-endoperoxide synthase 2 (PTGS2), raf-1 proto-oncogene serine/threonine k...
Elevated blood urea nitrogen alters the transcriptome of equine embryos. High blood urea nitrogen (BUN) in cows and ewes has a negative effect on embryo development; however, no comparable studies have been published in mares. The aims of the present study were to evaluate the effects of high BUN on blastocoele fluid, systemic progesterone and Day 14 equine embryos. When a follicle with a mean (±s.e.m.) diameter of 25±3mm was detected, mares were administered urea (0.4g kg-1) with sweet feed and molasses (n=9) or sweet feed and molasses alone (control; n=10). Blood samples were collected every other day. Mares were subjected to AI and the day ovulation was detect...
Expression of enzymes involved in polyunsaturated fatty acid synthesis in the stallion testis and epididymis. The aim of the present study was to characterise key enzymes involved in polyunsaturated fatty acid (PUFA) synthesis in the testis and epididymis collected from 2-year-old healthy warmblood stallions (n=10). The mRNA expression of fatty acid synthase, the Δ9-, Δ6-, Δ5- and Δ4-desaturases and elongases 6, 5 and 2 (encoded by the fatty acid synthase (FASN), the stearoyl-CoA desaturase (SCD), the fatty acid desaturase 2 (FADS2), the fatty acid desaturase 1 (FADS1), the delta 4-desaturase, sphingolipid 1 (DEGS1), ELOVL fatty acid elongase 6(ELOVL6), ELOVL fatty acid elongase 5 (ELOVL5), ELOVL ...
Analysis of the miRNA transcriptome during testicular development and spermatogenesis of the Mongolian horse. Numerous studies have shown that microRNAs (miRNAs) are essential for testicular development and spermatogenesis. In order to further characterise these physiological processes, three immature and three mature testes of the Mongolian horse were collected and six libraries were established. Using small RNA sequencing technology, 531 mature miRNAs were identified, including 46 novel miRNAs without previously ascribed functions. Among the 531 miRNAs, 421 were expressed in both immature and mature libraries, 65 miRNAs were found solely in immature testis libraries and 45 miRNAs were found solely i...
Cryopreservation of equine oocytes: looking into the crystal ball. Invitro embryo production has evolved rapidly in the horse over the past decade, but blastocyst rates from vitrified equine oocytes remain quite poor and further research is needed to warrant application. Oocyte vitrification is affected by several technical and biological factors. In the horse, short exposure of immature oocytes to the combination of permeating and non-permeating cryoprotective agents has been associated with the best results so far. High cooling and warming rates are also crucial and can be obtained by using minimal volumes and open cryodevices. Vitrification of invivo-matur...
Dimethyl sulfoxide and glycerol as cryoprotectant agents of stallion semen: effects on blastocyst rates following intracytoplasmic sperm injection of IVM equine oocytes. Numerous variables affect invitro blastocyst development following intracytoplasmic sperm injection (ICSI). The paternal factor is affected by initial semen quality, processing techniques and final selection of individual spermatozoon for injection. This study investigated whether there was an effect of sperm cryoprotectant agent (CPA) on equine invitro blastocyst production, and reviews recent developments examining how processing equine semen affects ICSI outcomes. Single ejaculates from five stallions were collected and processed in a freezing extender containing either 1M dimethyl sulfoxid...
Speed of in vitro embryo development affects the likelihood of foaling and the foal sex ratio. The success of invitro embryo production (IVEP) in horses has increased considerably during recent years, but little is known about the effect of the speed of invitro embryo development. Blastocysts (n=390) were produced by intracytoplasmic sperm injection of IVM oocytes from warmblood mares, cryopreserved, thawed and transferred into recipient mares on Days 3, 4, 5 or 6 after ovulation. The time required for invitro-produced (IVP) embryos to reach the blastocyst stage was recorded (Day 7 vs Day 8). The likelihood of foaling was affected by the speed of invitro embryo development and recipient...
Analysis of the uterine flush fluid proteome of healthy mares and mares with endometritis or fibrotic endometrial degeneration. The objective of this study was to evaluate the differences in the uterine flush fluid proteome between healthy mares and mares with endometritis or fibrotic endometrial degeneration (FED). Uterine flush fluid samples were collected from healthy mares (n=8; oestrus n=5 and dioestrus n=3) and mares with endometritis (n=23; oestrus n=14 and dioestrus n=9) or FED (n=7; oestrus n=6 and dioestrus n=1). Proteomic analysis was performed using label-free liquid chromatography-tandem mass spectrometry. Of 216 proteins identified during oestrus, 127 were common to all three groups, one protein was exclu...
Morphometric, subcellular, in vitro fertilisation and embryonic developmental assessment of mouse oocytes produced by anti-inhibin serum or pregnant mare serum gonadotrophin superovulation. This study compared the morphometric, subcellular characteristics, in vitro fertilisation (IVF) and embryonic developmental potential of metaphase II (MII) mouse oocytes obtained from females superovulated with either anti-inhibin serum-human chorionic gonadotrophin (AIS-hCG) or pregnant mare serum gonadotrophin (PMSG)-hCG. The oocyte's quantity, quality, zona pellucida (ZP) thickness, perivitelline space (PVS), diameter, microtubules, F-actin, cortical granules (CGs) and mitochondrial distribution were determined. Superovulation using AIS-hCG resulted in a higher numbers of oocyte/donor compa...
Seminal plasma has limited counteracting effects following induction of oxidative stress in donkey spermatozoa. The aim of this study was to evaluate the response of donkey spermatozoa to oxidative stress induced by hydrogen peroxide, and to determine whether the presence of seminal plasma modulates the sperm response to that stress. Nine ejaculates were collected, extended in skim milk extender and split into two aliquots. Seminal plasma was removed from the first but not second aliquot. Samples were subsequently split into four aliquots supplemented with different concentrations of commercial hydrogen peroxide (0, 100 and 250µM and 50mM). Aliquots were incubated at 37°C under aerobic conditions and ...
In vitro production of horse embryos predisposes to micronucleus formation, whereas time to blastocyst formation affects likelihood of pregnancy. Invitro embryo production is an increasingly popular means of breeding horses. However, success is limited by a high incidence of early embryo loss. Although there are various possible causes of pregnancy failure, chromosomal abnormalities, including aneuploidy, are important potential contributors. This study evaluated the frequency of micronucleus formation as a proxy for aneuploidy in invitro-produced (IVP) and invivo-derived horse blastocysts. Associations between IVP embryo morphology, frequency of nuclear abnormalities and the likelihood of pregnancy were investigated. IVP blastocysts ex...
Assessing equine embryo developmental competency by time-lapse image analysis. The timing of early mitotic events during preimplantation embryo development is important for subsequent embryogenesis in many mammalian species, including mouse and human, but, to date, no study has closely examined mitotic timing in equine embryos from oocytes obtained by ovum pick-up. Here, cumulus-oocyte complexes were collected by transvaginal follicular aspiration, matured invitro and fertilised via intracytoplasmic sperm injection. Each fertilised oocyte was cultured up to the blastocyst stage and monitored by time-lapse imaging for the measurement of cell cycle intervals and identifica...
Time of first polar body extrusion affects the developmental competence of equine oocytes after intracytoplasmic sperm injection. Assisted reproduction techniques (ARTs) have become widespread in the equine breeding industry. In particular, the combination of oocyte recovery from live mares followed by IVM and intracytoplasmic sperm injection (ICSI) has increased markedly among the ARTs used with valuable or low-fertility animals. There is currently no consensus among research groups regarding the optimal oocyte maturation period to produce high-quality embryos. In this study, we report the maturation dynamics of equine oocytes at different time points, from 20 to 40h (Experiment 1). In addition, in Experiment 2, equine ...
Perspectives on the development and incorporation of assisted reproduction in the equine industry. Marked changes in equine breeding technologies have occurred over the past 25 years. Although there have been numerous reviews on assisted reproduction techniques for horses, few publications include the acceptance and impact of these techniques on the horse industry. In this review, several techniques are discussed, with an emphasis on how they developed in the horse industry and altered equine reproductive medicine. Embryo transfer has become a widely used technology, allowing multiple foals to be produced per year. Embryos can be collected, cooled or frozen, and shipped to a distant facilit...