In vitro-produced (IVP) embryos are susceptible to oxidative damage as a consequence of the increased oxidative stress in culture systems. This study examined the effects of antioxidant supplementation during IVP of bovine embryos and was found that antioxidant supplementation reduced oxidative stress and the rate of cellular death, but did not increase embryonic development and cryotolerance. These findings encourages the use of antioxidants in IVP systems to modulate oxidative stress and promote embryo viability.

In our study, we investigated the effects of estrogen (E2) and estrogenic compounds on the regulation and localisation of Sprr2a protein in the mouse uterus. We concluded that Sprr2a protein is up-regulated by E2 via its nuclear estrogen receptors and also sensitively induced by BPA and OP, indicating that Sprr2a protein is a true E2-responsive protein in the mouse uterus. Our study proposes that Sprr2a protein can be valuable marker to predict and assess estrogenic activity in the uterus and offers useful tool to investigate unique regulatory mechanisms in non-squamous epithelia different from that in squamous epithelia.

In this work the essential tools for testicular germ cells transplantation were investigated in two flatfish species. The turbot, a domesticated species, was used as recipient and the Senegalese sole, a species whose reproduction in captivity is only guaranteed by wild broodstocks, as donor. The results of this work highlight the potential of germinal cell biotechnology in aquaculture and encourage further studies in the field of xenogenic transplantation for flatfish.

The combination ratio and dose of gonadotropins are key factors for IVF success. However, the dose-dependent effects of gonadotropins on rates of oocyte maturation, fertilisation and early embryo development in vitro remain unknown. The results of the present study could be applied to therapeutic clinical stimulation protocols to help improve IVF success rates.

Reproductivity is one of the most important traits in pig production but has low heritability, so the genetic characterisation is more and more important. The aim of the work is to identify the genes that might affect the high reproduction rate of Erhualian pig. In the present study, differential gene expression was identified in the ovaries between Erhualian and Pietrain pigs, and Egr4 was evaluated as a novel candidate gene for porcine reproductivity.

A novel direct bovine embryo-tagging system has been developed using polysilicon barcodes. This system allows the collective culture of embryos from different origins whilst preserving their pedigree, and facilitates the production of embryos from live animals of high genetic merit.

The cholesterol content of the sperm membrane is regulated in the epididymis. In this study we analysed the role of the epididymal cholesterol transport protein Niemann-Pick disease, type C2 (NPC2) protein in male fertility using genetically engineered NPC2-deficient mice. Spermatozoa from NPC2-deficient mice had less cholesterol and a reduced ability to fertilise eggs in vitro. These results could have important implications in the understanding of mammalian reproductive physiology and human infertility.

Low birthweight is a risk factor for adverse metabolic health. We investigated the relationship between prenatal and early postnatal growth trajectories and body composition in intrauterine growth-restricted (IUGR) and normal birthweight lambs of both sexes and showed that although IUGR lambs grew faster they remained smaller at weaning, but gender had the major influence on adiposity. Thus, prenatal growth status and gender are both likely to influence carcass composition and offspring health.

It has long been known that the amount and type of food can influence fertility, but exactly how is unknown. In this study, we asked whether common sugars were used differently by ovarian cells and found that theca cells use glucose and galactose, but not fructose, because they lack a fructose transporter. This study supports the theory that the amount and type of dietary sugar can affect ovarian function, and hence fertility.

Most attempts to introduce individual culture in cattle embryos have shown a reduction in development from a typical 25–35% blastocysts in group culture to less than 10% in individual culture. However, we observed that the very simple act of using serum-free culture medium based on BSA and ITS unexpectedly led to high blastocyst development in individual culture. The development of a semi-defined individual culture system is not only an important tool for research laboratories and practitioners working with bovine IVF; in addition this study upgraded the value of bovine embryos as a model for human IVF.

Knowledge of the changes that occur in spermatozoa during the process of fertilisation can be keys to determining the reproductive potential of males. We observed changes in sperm motility patterns and membrane fluidity after incubation of sperm samples in IVF media. These changes did not occur in all spermatozoa, enabling the identification of various sperm subpopulations. The distribution of these subpopulations was found to be related to fertilising ability.

We investigated the effect of mechanical stimuli on mouse embryonic development from the 2-cell to blastocyst stage using mechanical vibration systems (MVSs). The MVS transmitted mechanical vibration power efficiently to embryos and resulted in a significant decrease in development to the morula or blastocyst stage after 2 days. These results suggest that mouse embryos are more sensitive to physical stimuli than human or pig embryos because of their thinner zona pellucida.

Blastocyst development in the well-of-the-well (WOW) culture system is better than in conventional culture systems with the same embryo number. To compare the concentration of chemical factors between conventional and WOW culture, a model was constructed to calculate concentrations. The findings suggest that the WOW culture system is better than conventional group culture because of increased final concentrations of autocrine factors and higher diffusion kinetics of waste materials.

Gonocytes are primitive germ cells responsible for the production of spermatozoa in male testes. The objective of this study was to identify a cell surface marker for gonocytes in pigs. The findings from this work will not only help to elucidate the characteristics of gonocytes, but also to facilitate their subsequent manipulation.

This study evaluated the effects of oestradiol (E2) plus progesterone (P4) administration on the prostate of castrated female gerbils using histological and immunohistochemical techniques. Treatment of castrated gerbils with E2 + P4 restored the secretory activity and morphological structure of the female prostate. These findings may indicate a synergistic action of E2 and P4 in maintaining healthy prostate physiology, and may also lead to the development of treatments for important prostate diseases.

Adhesion molecules are thought to be highly important in stem cell niches including the spermatogonial stem cell niche. Here, we investigate the expression of claudin-8, a tight-junction protein, in the testis, and show expression in undifferentiated spermatogonia and associated Sertoli cells. Our findings suggest a role for claudin-8 in the cellular interaction between those cells, and in the regulation of self-renewal and differentiation processes.

This study evaluated the production and cryotolerance after freezing or vitrification of embryos from superovulated Nelore heifers supplemented with rumen-protected polyunsaturated fatty acids (PUFA). Heifers kept in pasture were supplemented in a crossover design with either PUFA (predominantly linoleic acid; n =40) or a fat-free supplement with additional corn (n = 40) before superovulation. Dietary PUFA rich in linoleic acid did not improve embryo production, but compromised the cryotolerance of frozen or vitrified embryos.

Bacterial infections pose a serious risk for ongoing pregnancy, but can also have a great impact on fecundity. By using an animal model to investigate the influence of the major bacterial components lipopolysaccharide (LPS) and peptidoglycan (PGN) on pregnancy, we discovered that LPS and PGN induce different types of reproductive failures. Our animal model can serve as a valuable tool to gain a better understanding of the factors underlying infection-induced pregnancy complications in humans.

It is widely known that the energy substrate and hyaluronic acid added to the culture medium of porcine in vitro-produced embryos influence their development. The aim of the present study was to determine the putative synergistic effects of glucose or pyruvate–lactate and hyaluronic acid on embryo development, as well as on the sex ratio. Interestingly, high concentrations of hyaluronic acid decreased blastocyst rates in both energy substrate groups, but only affected the sex ratio of embryos cultured with pyruvate–lactate.

In our study, we investigated the transcriptional profile and role of WNT3A signaling in maintaining the pluripotency of buffalo embryonic stem (ES) cells as well as in inducing their differentiation. We concluded that WNT3A, in combination with exogenous FGF-2 and LIF, induced proliferation of undifferentiated ES cells, while differentiation studies revealed its role in causing formation of scaffold-like structures and preventing differentiation into neuron-like cells. Thus, WNT3A signalling pathway is necessary both for maintaining pluripotency and for directed differentiation of buffalo ES cells.

This study evaluated superovulatory responses and in vivo embryo production in 33 Nelore cows treated with FSH starting at 1 (D1) or 2 (D2) days after ovum pick-up (OPU). Cows in Group D2 cows had a greater superovulatory response (18.9 vs 9.1 corpora lutea; P < 0.03) and more freezable embryos (3.2 vs 1.3; P < 0.05) than Group D1 cows. Therefore, it is recommended to wait at least 2 days before starting superovulatory treatment with FSH after OPU.

In contrast with other farm animals, only few criteria correlated with developmental competence have been investigated in equine oocytes so far. The aim of the present study was to analyse correlations between zona pellucida birefringence (ZPB) and molecular signatures and developmental competence. Developmentally competent oocytes are larger in size, have higher ZPB values and exhibit a typical genetic signature compared with oocytes of lower quality.

A drastic decrease of oocyte viability and fertilisability occurs during post-ovulatory ageing (POA). The aim of this study was to determine if POA could impair oocyte quality by altering the expression level or localization of proteins implicated in cell survival and chromosome segregation. Aged oocytes showed altered distribution of some spindle-associated proteins and a decrease in both H3S10 phosphorylation and Akt expression levels. All these events could impair fertilization by inducing oocyte apoptosis.

The insulin-like growth factor (IGF) system of ligands and binding proteins constitute a complex regulatory system on which many aspects of reproduction and embryo growth are dependent. Very little is known about uterine IGF-1 and binding proteins (IGFBP) and how these are affected by stage of cycle and concentration of progesterone. This study indicates that uterine concentration of IGF-1 and IGFBP in cattle differ from that of plasma and suggest that they are under dynamic control throughout the oestrous cycle.

The existence of wild wood bison is threatened by tuberculosis and brucellosis introduced more than 90 years ago by domestic cattle. We developed a technique for synchronizing ovarian activity among bison as a necessary step in establishing a bio-bank of disease-free embryos that could be used to restore once populous herds. This is the most recent of our studies focused on establishing reproductive technologies to facilitate repopulation of the largest land mammal in the Americas.

Controversy exists in determining the extent of negative impact of varicocele on male fertility and the value of varicocele surgery in correcting infertility. The study aimed to identify predictive factors of successful varicocele surgery for treating male infertility induced by varicocele, and found that age and preoperative sperm density are the predictive factors. Our results may allow clinicians to predict surgical improvement in fertility of male patients with varicocele.

Bilateral regulation of embryo development can exist in the cow, although the mechanism remains basically unexplored. In uterine fluid, hexoses and proteins related to embryo development, but not to embryonic sex, were found to change between left and right uterine horns. These discoveries may lead to a better understanding of uterine physiology, fertility and bilateral pregnancy regulation.

Although conjugated linoleic acids (CLA) are employed frequently in dairy cow nutrition, their effects on the bovine preimplantation embryo have not been fully assessed so far. In the present study an effect of CLA and the carrier substance DMSO on morphological and molecular bovine embryo quality was detected in an in vitro model. This suggests that effects evoked by CLA might result in altered early embryonic development.

Pretreatment of oocytes with sublethal high hydrostatic pressure (HHP) can improve the developmental competence of cloned embryos, although the underlying molecular mechanism is poorly understood. In the present study, we used DNA microarray-based genome-wide gene expression profiling and found that HHP treatment predominantly accelerated the use of maternal mRNA (mostly involved in embryonic development) in oocytes and activated the expression of imprinting genes, such as DLX5, which benefits development. Our findings suggest that HHP positively affects genomic reprogramming during embryonic development.

The oviduct plays a crucial role in sperm storage, maintenance of sperm viability and sperm transport. We investigated the effects of oviductal cell culture passage number, oviductal cell age and spermatozoa–oviduct coincubation times on gene expression in oviductal cells. The data suggest that the oviductal cells lose some of their properties as a result of aging. This has important implications for the study of spermatozoa–oviduct interactions in in vitro cell culture systems.

Cloning miniature pigs using handmade or oocyte bisection cloning techniques in combination with embryo aggregation has provided proof-of-principle for this cost-effective technology in other species. The aim of the present study was to improve cloned embryo development by implementing these two biotechnologies; a beneficial effect on cloning efficiency was shown. The technology in this study is potentially useful in organ transplantation, species conservation and establishing embryonic stem cells for the study of human diseases.

Cystic ovaries can be a problem in sows and there are many questions related to cyst formation. In the present study, development of cysts in non-hormonally-treated, lactating sows was studied and the results show that cyst formation is related to insufficient LH pools and disturbed oestradiol feedback, resulting in continued follicle growth. Risk of cyst development can be reduced by not weaning sows too early.

Despite considerable investigations into the pathogenesis of endometriosis, it remains poorly understood. The formation of new vessels (angiogenesis) and inflammatory reactions are known to be crucial for the development of the disease and were investigated in this study in women with endometriosis, before and after danazol treatment. Danazol treatment appears to be highly effective in relieving pain and decreasing CA-125 concentrations. In addition, for the first time we provide the evidence that danazol may stimulate angiogenesis. Implementing an algorithm described in this study would result in the diagnosis of 60% of cases of endometriosis.

Noninvasive assessment of oocyte quality can be a determining factor in the outcome of assisted reproductive technology cycles. The aim of the present study was to examine associations between the presence of the meiotic spindle and zona pellucida birefringence and the morphology of in vivo-matured and IVM human oocytes. The findings suggest that clinical IVM is a safe technology for enhancing the maturation and integrity of oocytes.

Complete fertilisation failure is an emotional tragedy for patients receiving in vitro fertilisation treatment. To detect early sign of fertilisation and prevent oocyte ageing, we evaluated the extrusion of the second polar body prior to pronuclei development. Our results showed early rescue intra-cytoplasmic sperm injection on oocytes without extruding the second polar body 4 hour following insemination is an effective method to prevent complete fertilisation failure for patients with mild or moderate male infertility.

At the time of implantation the uterus allows blastocyst implantation; however, at other times of the cycle, it prevents implantation. Mucins are a family of cell-surface proteins that normally impede successful implantation. This study found that mucin 13 may support implantation while mucin 15 may prevent implantation. These new findings in the rat uterus add to the knowledge of factors that promote implantation as well as prevent implantation, which could be useful targets for reproductive technology.

The identification of markers of oocyte quality would have significant benefits for assisted reproduction in domestic animals and in humans. The aim of this study was to identify non-invasive markers of oocyte quality by examining the components of the follicular fluid in which the oocyte develops and the somatic cells associated with it. The observed association between follicular fluid metabolites and oocyte developmental competence could be useful for selecting the best eggs for IVF, or to optimise the IVF protocol.

Histone deacetylase inhibitors (HDACis) have been widely used to improve the developmental competence of embryos derived from somatic cell nuclear transfer (SCNT). The present study was conducted to elucidate the effects of valproic acid (VPA), a recently-characterized HDACi, on the early development of bovine SCNT embryos and the underlying mechanisms of these effects. We revealed that VPA enhances the developmental competence of bovine SCNT embryos by alleviating ER stress and its associated developmental damage.

The physical environment used in in vitro embryo production has changed little over the years. This study describes a novel polydimethylsiloxane (PDMS) well-insert system that can successfully mature oocytes and culture embryos in an individually-identifiable manner without compromising, and perhaps enhancing, developmental potential in pigs. The application of the PDMS well-insert system to embryo production may allow the development of a more physiological, efficient culture environment; meanwhile, tracking of individual oocytes and embryos becomes feasible.

Pre-eclampsia is a serious pregnancy complication. There are currently no efficacious treatments available to halt disease progression besides delivery of the baby and placenta; thus, clinicians are often forced to deliver infants regardless of gestation. Herein, we show that the placental-specific protein pregnancy-associated plasma protein A2 (PAPPA2) is increased in severe early onset pre-eclampsia and up regulated with hypoxia. Given the pathogenesis of pre-eclampsia is so poorly understood, characterisation of proteins upregulated in this disease is essential if better biomarkers or treatment options are to be identified or developed.

Changes in maternal bone mass during pregnancy and lactation facilitate calcium transfer to offspring for normal skeletal development. Mothers suffering from uteroplacental insufficiency, which reduces blood flow to the fetus, give birth to offspring who have poor bone health as adults. We have shown that these mothers don’t gain and subsequently lose bone during their pregnancy and lactation, and this reduction in calcium transfer is a likely contributor to the development of poor adult bone health in these offspring.

Selection for ovulation rate is an indirect way to improve litter size. Ovulation rate variability between breeds may be associated with transcriptome profiling. In the present study, we investigated causes of low ovulation rate in the Brazilian Piau breed compared with a commercially available line. Piau gilts exhibited a different pattern of follicle development and higher ‘activity’ of cell death genes. This helps elucidate the genetic control of prolificacy and achieve genetic gains in litter size.

Early embryo loss is one of the main factors affecting reproductive efficiency in cattle and the steroid hormone progesterone plays a major role in establishing uterine receptivity prior to implantation. The aim of this study was to test the effects of administration of human chorionic gonadotrophin (hCG) during the first few days after ovulation on progesterone production by the corpus luteum (CL). Administration of hCG on Day 2 after oestrus increase the size of the original CL and the concentrations of progesterone from Day 6 onwards and may be a useful strategy to promote conceptus development and pregnancy establishment.

The steroid hormone progesterone (P4) plays a central role in the establishment and maintenance of pregnancy. The present study examined the effect of short-term P4 supplementation on conceptus development in cattle and showed that although exogenous progesterone was beneficial to the early conceptus, in some cases it resulted in compromised corpus luteum function. The results indicate that P4 supplementation strategies aimed at stimulating corpus luteum development may be most effective.

Primitive male germ cells (gonocytes) from cattle have glycan epitope α-N-acetylgalactosamine (GalNAc) residues, which are recognised by the lectin Dolichos biflorus agglutinin (DBA), on their cell surface. In culture, DBA-coated culture dishes can effectively trap gonocytes and support their survival and proliferation. The GalNAc–DBA complex supports colony formation, germ cell and stem cell potentials of gonocytes in vitro and provides a useful system to analyse the role of cell surface glycan epitopes on early spermatogenesis.

In search of new non-hormonal and non-steroidal contraception therapies, the potential of liver receptor homologue-1 (LRH-1) as a drug target was explored. Temporary downregulation of LRH-1 in female mice resulted in complete infertility that was fully reversible, with microarray expression analysis revealing that multiple aspects of the ovulation process were affected, most prominently progesterone biosynthesis. The data support the development of an LRH-1 antagonist for contraception.

The human Y chromosome is susceptible to structural rearrangements because of the repetitive nature of its genetic sequences, and partial deletions in the Y chromosome are often linked to male infertility. Herein we identified and characterised one of the genetic configurations without sY1191 at the AZFc locus. The results exemplify the prevalence of variations in the human Y chromosome among infertile men.

Uterine secretions/histotroph provides essential nutrition to the developing conceptus during early pregnancy. The objective was to examine the effects of stage of cycle and concentration of circulating progesterone on the availability of amino acids and glucose in the uterine environment during the pre-implantaion period of conceptus development. Total recoverable quantities of 22 amino acids were greater on Day 13 compared with Day 7; and on Day 13, the amounts of Asn, His and Thr were lower in a low P4 environment. Stage of oestrous cycle and progesterone play important roles in modulating amino acids in histotroph, a potentially critical factor for early embryonic/conceptus survival.

Oocyte cryopreservation is important for assisted reproductive technologies (ART) in both human and animals. This study showed that ovine oocytes vitrified at GV stages using cryoloop have the ability to be matured, fertilised and subsequently develop in vitro and produce good quality blastocysts at comparable trends like those seen in fresh control groups. The vitrification protocols used here may be a promising tool for the establishment of oocyte cryobanks.

This series of experiments represents the first attempt to manipulate meiosis in oocytes from the domestic cat, using chemicals that affect intracellular concentrations of cyclic adenosine monophosphate (cAMP). Although the effects of decreasing cAMP degradation (inhibition of meiosis) were consistent with other species, the effects of increasing cAMP production (stimulation of meiosis) were unique to feline oocytes. Such species-specific effects emphasise the need for comparative studies in taxa like Carnivora, where basic information about reproductive biology is limited.

Heat stress has long been considered an important cause of compromised fertilisation in farm animals. The objective of this study was to investigate the signalling pathway by which bovine spermatozoa react to heat stress. The results show that mitogen-activated protein kinase (MAPK) 14 is the key signalling pathway, and inhibition of this pathway can possibly be an interesting option for minimising the adverse effects of heat stress.

High-producing dairy cows are subfertile, which may be due to premature ovarian senescence. In the present study, 5% of the total population of culled dairy cows (4–8 years old) has several distinctive features of premature ovarian failure, such as a reduced antral follicle count, ovarian reserve, low anti-Müllerian hormone concentrations in the follicular fluid and poor in vitro oocyte developmental competence. This population may represent a model to address can address the causes of reduced fertility in high-yielding dairy cows, as well as the condition of premature ovarian aging in single-ovulating species.

Egg yolk protects brown-bear spermatozoa during cryopreservation but has some disadvantages and thus we propose to replace it by another component with similar activity. Low-density lipoproteins (LDL) and soybean lecithin were evaluated and we observed that the LDL-based extender exhibited a high anti-oxidant capacity and protection of the viability of frozen spermatozoa. We propose that LDL could be a useful substitute for egg yolk in these extenders.

Inclusion of the high-fibre ingredient sugar-beet pulp in pig pre-mating diets has been shown to improve oocyte quality and embryo survival; however, it is not a commercially viable feed ingredient in Australia. This study evaluated the effects of two alternative fibre sources (lupin and bran) and found that lupin-fed pigs had improved oocyte maturation and embryo survival compared with control and bran-fed pigs. These findings could potentially be implemented as a strategy to improve litter sizes in commercial piggeries in Australia.

The present study provides new information to increase our understanding of bovine ovarian folliculogenesis. During the in vitro growth of preantral follicles, FSH and/or growth differentiation factor (GDF)-9 promote follicular growth and antrum formation. Moreover, GDF-9 stimulates the expression of versican and perlecan mRNA, and interacts positively with FSH to increase the expression of HAS2. These data are essential for improving the in vitro development of good-quality oocytes.

The widespread use of plastics provides us cheaper, lighter and more durable products, but what are the effects on human reproduction? The present study reveals that that mono-n-butyl phthalate, a metabolite of a solvent used in the production of plastics, impairs embryo developmental potency and cause a series of intracellular biochemical changes. The results highlight the need to pay more attention to the effects of environment pollutants on human reproductive health.

In this research, coyotes were successfully cloned using domestic dog oocytes and surrogates. The aim was to examine whether domestic dog oocytes and surrogates can be used to give birth to a different species using interspecies somatic cell nuclear transfer (iSCNT) technology. This success has provided the promise of utilising similar techniques to clone endangered canids in the future, subsequently leading to preservation of nature's diversity.

Elephants have the longest reproductive lifespan of land-based mammals; therefore, it is of interest to study aspects of their ovarian biological clock. The numbers of ‘eggs’ present were counted in individuals between puberty and reproductive senescence to reflect this ovarian activity. The results provide an interesting comparison with the human ovarian clock and also give a base study against which the egg reserve of relatively infertile captive elephants may be compared.

The autophagic process was detected in preovulatory follicles isolated from Danio rerio. Modulation of apoptotic and autophagic processes was demonstrated in vitellogenic follicles from females fed a probiotic (Lactobacillus rhamnosus IMC 501). The results show a positive effect of L. rhamnosus on ovarian physiology, suggesting that probiotics may be developed as a new biotechnology to improve reproduction.

The oxygen environment of the oocyte is crucial to its quality and is largely determined by the oxygen consumption of the cells surrounding it. This work aimed to measure the oxygen consumption rate of such ovarian cells in cows and subsequently showed using mathematical modelling that early-stage oocytes may experience oxygen starvation. These results may be key to understanding oocyte development and optimising in vitro culture conditions.

The present study investigated the effects of oocyte morphology, incubation time and different supplements in the oocyte maturation medium on the number of chromosomal abnormalities in IVF-derived early bovine embryos. The results indicate that a combination of good-quality oocytes, a short incubation period and controlled culture medium can decrease the rate of chromosomal abnormalities, increasing the overall efficiency of cattle in vitro production.

The serotonin regulates gonadotrophin secretion. The aim of this study was to analyze the effects of an increase of both systemic and in-ovarian bursa of serotonin on onset of puberty and ovarian function. We proposed that serotonin participates in the modulation of the neuroendocrine mechanisms that regulate the hypothalamus–hypophisis–ovary axis and culminates with the regulation of follicular growth, ovulation, and steroidogenesis. Also that serotonin acts at the ovary, directly modulating steroidogenesis.

Anurans exhibit a greater reproductive diversity than any other vertebrate order. However, studies investigating optimal conditions for artificial fertilisation are limited to aquatic-breeding species. The present study investigated the effects of fertilisation medium osmolality, sperm concentration and short-term oocyte storage on fertilisation success in a terrestrial-breeding anuran, Günther’s toadlet. Optimal sperm concentrations were lower, and optimal fertilisation media osmolalities both higher and broader, than those previously reported for aquatic species.

Piglets with low initial growth rates remain poor growth performers throughout the post-weaning period, which increases herd variability and reduces overall production efficiency. Blood was collected at birth and higher levels of alpha-1 acid glycoprotein, the predominant protein in fetal piglet plasma, were associated with runts and poor growing pigs. Availability of a biomarker that is reflective of in utero development or fetal maturation may serve as an early predictor of overall growth potential.

Spermatogonial stem cells are at the core of male fertility, undergoing self-renewal and differentiation. The mechanisms underlying these processes are yet to be determined. The aim of the present study was to determine the effects of factors crucial in the testis microenvironment on the short-term culture of buffalo spermatogonia. Supplementation of the in vitro culture medium with glial cell line-derived neurotrophic factor, fibroblast growth factor 2 and epidermal growth factor had beneficial effects on the self-renewal and proliferation of spermatogonial cell colonies and their use appears suitable for short-term cultures of buffalo spermatogonia.

Laboratory rats are commonly used experimental animal models in many areas of biomedical research to gain a better understanding of the genetic basis of human diseases. In contrast with spermatozoa from other mammalian species, rat spermatozoa are known for their hypersensitivity to physical interventions, such as handling, centrifugation, gradient separation, hypothermia and freezing. The present study provides fundamental information on the detrimental effects of reactive oxygen species and mitochondrial dysfunction on rat sperm motility after the application of physical stress.

In the dog, oocyte maturation, fertilisation and early embryo development take place in the oviduct in the presence of high progesterone levels. To investigate the potential effects of progesterone in the canine oviduct, the expression and localisation of nuclear and membrane progesterone receptors were examined for the first time at precise times around ovulation. Our results support the hypothesis that progesterone is an important regulator of oviductal functions and gamete maturation through different complementary pathways.

Micronutrient (folic acid, vitamin B₁₂) deficiencies during the preconception period play a critical role in determining pregnancy outcome. The current study demonstrates that folic acid and vitamin B₁₂ deficiency leads to an abnormal oestrous cycle in rats, which can be ameliorated by omega 3 fatty acid supplementation. This study may have implications in fertility and pregnancy outcome.

Glucose flux through metabolic pathways during cumulus–oocyte maturation plays a crucial role in determining oocyte developmental competence, both in vitro and in vivo. In these experiments we examined the possible roles of the various pathways during mouse oocyte in vitro maturation (IVM) with an emphasis on the hexosamine biosynthesis pathway. Interestingly, glucose or glucosamine supplementation during the first hour of IVM was essential for further development.

There are some hormonal techniques (eCG administration), used to improve fertility in cattle, which change the organism’s capacity to produce progesterone; however, the basis for this is yet not completely understood. The present work reveals some of the molecular pathways triggered by eCG and helps our understanding of which mechanisms to target in order to enhance reproductive rates.

To improve embryo in vitro production techniques, it is necessary to understand the variables involved in the process. In the present study we investigated the control of glycolysis, a key metabolic pathway involved in cell energy production, in cumulus–oocytes complexes during IVM and revealed a link between glycolytic activity and the oxidative and mitochondrial metabolism of the oocyte. The findings of the present study will help us understand the relationship between the glycolytic pathway in cumulus cells and events related to the maturational capability of the oocyte.

The aim of the present study was to investigate whether reduced glutathione (GSH) and procaine hydrochloride (ProHCl) were able to counteract the destabilisation of nucleoprotein structure of the sperm head that usually occurs during boar sperm cryopreservation. When GSH and ProHCl were added to freezing extenders at a final concentration of 2 mM, the number of non-disrupted sperm head disulfide bonds after thawing was higher than the negative control. In conclusion, adding GSH and ProHCl to freezing extenders is beneficial for the stability of nucleoprotein structure of cryopreserved boar spermatozoa.

The regulation of uterine function is a complex multifactorial process, considered paramount for equine fertility. The present study investigated the presence of cytokines (tumour necrosis factor (TNF)-α, interferon-γ, Fas ligand) and their receptors in the mare endometrium and the ability of TNF-α, together with steroid hormones and oxytocin, to modulate endometrial physiology. A coordinated action between cytokines and ovarian hormones may regulate secretory, vascular and proliferative functions in the equine endometrium.

In the present study, the pain and stress responses to tail removal (female and male lambs) and castration (male lambs) were investigated. Plasma cortisol and adrenocorticotrophin concentrations increased after the procedures in both sexes, with less consistent responses in endorphin levels. Prenatal exposure of the fetus to dexamethasone blunted the cortisol response to tail removal in female lambs, but did not affect the response to the combined procedure in males, suggesting sex differences in the development of the hypothalamic–pituitary–adrenal axis.

Using oocytes from in vitro grown and matured follicles is an alternative to overcome the limited supply of mature, fertilisable oocytes for assisted reproduction techniques. The aim of the present study was to investigate the effects of a dynamic medium containing growth differentiation factor 9 (GDF-9) and FSH on the survival, activation, steroidogenesis and in vitro growth of caprine preantral follicles during long-term culture. The results show that using a dynamic GDF-9/FSH medium resulted in significant and continuous follicular growth and maintenance of follicular ultrastructure, which may contribute to improvements in vitro embryo production.

Various intraovarian chemical transmitters are important for gamete development, a process that depends on communication with neighbouring cells. One of the many functions controlled by intraovarian transmitters is ovarian cell death, which is important in phenomena such as ovulation and tumourigenesis. In the present study, we show that extracellular ATP acting on specific membrane receptors expressed in the ovarian epithelium induces cell death in this layer, and that this action is regulated throughout the oestrous cycle, suggesting a role for ATP signalling during ovulation.

Literature shows that women can fall pregnant with another baby whilst being already pregnant (this is called superfetation). This review evidences a small discordance between gestational age in superfetation twins (range: 2–4 weeks). This difference is compatible with an atypical increase in oestradiol levels in the luteal phase occurring between 1 and 3 weeks after the ovulation that allowed the first pregnancy. However, the likelihood of the occurrence of superfetation in humans is extremely low.

When stored in liquid form, bull spermatozoa can live for up to 2 weeks; however, its ability to achieve a pregnancy is compromised after just 4–5 days of storage, which may be a consequence of changes in the sperm cell membrane lipid profile caused by attack from reactive oxygen species. This study, which aimed to investigate the effect of the addition of long-chain fatty acids to bull spermatozoa in vitro, found that while palmitic and oleic acids proved beneficial to spermatozoa, docosahexaenoic and eicosapentaenoic acids were detrimental. Thus, the addition of palmitic and oleic acids to bull spermatozoa in vitro could prolong their fertile lifespan.

The sperm cryopreservation process affects the quality and fertilising ability of the spermatozoa. The aim of this study was to determine if the quality and functionality of frozen–thawed boar spermatozoa could be enhanced by treating the spermatozoa before cryopreservation with cholesterol-loaded cyclodextrins. The results show that the ability of the spermatozoa to bind to oviductal epithelial cells in vitro was enhanced, which could have some effect on fertilisation success in vivo.

Embryo development is dependent on a tight regulation of the local maternal immune system, which is critically important in pregnancy recognition as well as facilitating implantation. Our aim was to document the expression of a broad range of immune-related genes in the endometrium of heifers producing viable and degenerate embryos on Day 7 after oestrus. We found that disturbances in the immune response at this stage of embryonic development can have detrimental implications for embryo survival.

A better understanding of the interaction between the oocyte and surrounding cumulus cells is of crucial relevance for fertility. We have assessed the expression of receptors for oocyte-derived factors during in vitro maturation and demonstrated that FSH dramatically stimulates expression of receptors for fibroblast growth factors in bovine cumulus cells. These data provide further evidence for an important role of fibroblast growth factors in follicle development.

Manipulation of female fertility has become an increasingly important tool for the management of captive and free-living marsupial populations. This study demonstrated that pre-pubertal GnRH agonist treatment significantly delays the onset of puberty in female tammar wallabies. This has potential application for the management of overabundant kangaroo populations and enhances our understanding of the physiological processes that occur at the time of puberty in this model species.

Freezing of human eggs has a wide and significant clinical benefit for many women, including the preservation of female fertility before its loss due to disease or aging. The aim of the present study was to determine the optimal freezing solutions that can be used to preserve the structural and functional integrity of human eggs. The outcome will make a significant practical impact in the area of egg freezing, hence contributing to the improvement of female fertility.

Bisphenol A (BPA), a chemical used in many consumer products, interferes with the endocrine system of mammals, including humans. The present study investigated the effects of BPA on spermatogenesis and semen quality, and found that BPA decreased both the quantity and quality of mouse spermatozoa, resulting in abnormal offspring that were smaller and had a low-quality pelage. The results demonstrate that BPA hampers spermatogenesis and the development of offspring.

The European brown hare exhibits superconception, whereby the maternal reproductive tract hosts two sets of conceptuses at different developmental stages. The early embryo development of the hare has not been described. In this study, we studied oviduct transport and implantation stages by embryo flushing, live high-resolution ultrasound and by histology of age matched pregnant tissues. In contrast to the rabbit, not only total pregnancy length, but also transition phase of the early embryos from the ovidcut to the uterus is prolonged in the hare, probably enabling superconception.

Genes of the Y chromosome long arm are crucial for male fertility, but now it appears that they can also influence female reproduction. We have shown that female mice sired by males with the impaired Y chromosome differ in some periovulatory processes from genetically identical females but having fathers with the intact Y chromosome. Since females do not inherit Y chromosome, its influence consists probably in epigenetic modifications of genetic material in X-bearing spermatozoa.

The need for insulin in the medium in which preantral follicles are cultured in vitro and its interaction with FSH remain controversial. Thus, we evaluated the association between different concentrations of insulin and FSH in the development of canine preantral follicles in vitro. In the absence of FSH, a high insulin concentration is beneficial for follicular viability, but for best follicular growth it is recommended that the association of insulin with FSH is added to the culture medium.

Assisted reproduction techniques in the bovine are associated with high intrauterine mortality. We investigated the development of embryos and fetal membranes and found that the yolk-sac and the cardiovascular system seem to be vulnerable to morphogenetic alterations, especially in cloned embryos. Because the abnormalities observed may be responsible for the high mortality rate, future studies into gene expression and early vascularisation processes seem to be important.

Both the quality and yield of cloned buffalo embryos was higher following the use of cells obtained from fetal or newborn buffalo calves than those obtained from adult buffaloes, probably because of their less differentiated state. A live normal calf was born following transfer of frozen–thawed cloned buffalo embryos to a surrogate recipient. This suggests that cloned embryos can be stored frozen for long periods of time.