Reproduction, Fertility and Development
Number 7 2012
To better explore the pathogenesis of polycystic ovary syndrome (PCOS) disease so as to find a better treatment, we performed an initial proteomic study. Thirty-two protein spots were shown to be significantly differentially expressed between PCOS and normal follicular fluids, of which 20 unique proteins were identified to be associated with cellular metabolism and physiological processes. These results increase our understanding of PCOS and the identified genes may serve as candidate biomarkers to develop diagnostic and therapeutic tools.
Paracrine cell signalling is believed to be important for ovarian follicle development, and a role for some members of the fibroblast growth factor (FGF) family has been suggested. This work reviews the main controlling mechanisms of preantral and antral follicle development, with the main focus on the regulation of FGF family members, in particular FGF-2. These data confirm the importance of the FGF family in mammalian reproduction control.
At-risk pregnancies are commonly treated with progesterone; however, the potential effects of supraphysiological concentrations of progesterone on the developing male are not known. Although sexual interest was not influenced in male rats treated neonatally with progesterone in the present study, these rats exhibited a reduction in copulatory behaviour and ejaculation. This suggests that the development of male sexual behaviour can be influenced by the prenatal environment, including by hormones that are prescribed for at-risk pregnancies.
Thyroid hormones are essential for fetal development because they act directly on the placenta. However, the role of the placenta in the complexity of maintaining a pregnancy and in impaired fetal development arising out of hypothyroidism is unknown. The objective of this study was to evaluate fetal development, placental morphology, vascularisation and the rate of proliferation and cell death of the placenta in rats with hypothyroidism. We observed that hypothyroidism impairs fetal development by affecting all layers of the placenta. It interferes with placental vascularisation, reduces the proliferation and cellularity and increases cell death of the placenta. These results allow us a better understanding of the pathogenesis of placental alterations and fetal growth restriction that occurs in hypothyroidism, which may contribute to more appropriate therapeutic interventions.
High between-animal variability in ovarian responses to gonadotrophin treatment remains a major limit to the development of embryo biotechnologies in cattle. We show that anti-Müllerian hormone (AMH) endocrine concentrations are highly repeatable and tightly correlated with ovarian responses and embryo production in cows. We propose a prognostic method to discard low-responding individuals by the determination of AMH concentration in a single blood or plasma sample, taken from animals several months before their entry into embryo production protocols.
The aim of this study was to determine whether controlled ovarian hyperstimulation (COH) and in vitro maturation (IVM), the two common clinical procedures in human IVF treatment, have an impact on mitochondrial status in oocytes. The results indicate that COH and IVM inhibit mitochondrial DNA replication and alter mitochondrial function. The mitochondrial damage may partly explain the low efficiency of IVF and high rate of embryonic loss associated with these clinical procedures.
The reproductive seasonality of sheep suggests that melatonin receptors may be present in ram spermatozoa. The aim of the present study was to confirm the presence of these receptors in ram spermatozoa. Four sperm subpopulations were identified on the basis of immunocytochemical labelling patterns for MT1 receptors, but there was only one pattern of labelling for MT2 receptors. The biochemical pathway triggered by these receptors and their function in terms of fertility are currently under investigation.
Establishment of pregnancy in cattle is most vulnerable during the first few weeks, when the embryo is reliant on the uterine protein environment for development. We demonstrate that the growth of conceptuses from asynchronous (Day 9) transfers is superior to that of AI controls. Proteomic profiling of uterine luminal flushings identified 10 proteins that increased in abundance at this time point. Defining and characterising the uterine proteins affecting embryo growth could lead to intervention strategies to improve pregnancy rate.
Immunocastration suppresses reproductive function, making it an attractive tool to improve the management of gonad-intact animals and an alternative to surgical castration. In the present study, neonatal immunocastration in bulls with a novel vaccine caused temporary endocrine but long-term disruption of testicular development, delaying puberty by 8 weeks. This supports the hypothesis of a developmental window during testicular development, such that disturbance of the endocrine drive to the gonads results in long-term impairment of gonadal function.
Mediterranean buffaloes reproduce principally in autumn, when nocturnal melatonin levels are high, although variability in the melatonin receptor 1A (MTNR1A) gene also allows for reproductive activity in spring. Thus, the aim of the present study was to investigate the relationship between reproductive performance and variability in the MTNR1A gene. Buffaloes with the T/T and C/T genotypes exhibited a shorter interval between the first and second calving, because reproductive activity occurred during days with a long photoperiod. The findings of the present study could allow the selection at birth of buffaloes that would also be able to reproduce in spring, with a consequent deseasonalisation of production.
No defined in vitro model currently exists to allow detailed and systematic investigation of maternal communications with gametes and embryo. Here we report establishment and characterisation of an in vitro model based on the interaction of boar spermatozoa with a porcine oviductal cell line. The simple in vitro assay system described here has the potential to be used in high-throughput genomic and proteomic approaches as well as being itself further developed towards an automated assay system for understanding maternal interactions with gametes and embryos.
Devil facial tumour disease (DFTD) is the primary cause of the current rapid decline of wild Tasmanian devils. This study has established the range of variation in male reproductive tract component weights and sizes, sperm motility and serum testosterone and cortisol production to demonstrate that male reproduction does not appear to be restricted by season nor inhibited by DFTD. This information increases our understanding of the potential effects of DFTD on the physiology and reproductive potential of wild male devils.
Electroejaculation (EEJ) can be used to collect sperm samples to evaluate fertility and develop sperm storage techniques in wildlife species. The limited number and quality of ejaculates obtained in this study suggest that the reproductive anatomy of the Tasmanian devil does not facilitate the use of traditional EEJ techniques for the collection of semen. Information gained on seminal characteristics can be used to optimise sperm storage techniques towards the development of a genome resource bank for this endangered species.