Reproduction, Fertility and Development
Number 3 2016
Low circulating progesterone in the week following ovulation has been implicated in poor fertility in cattle. The aim of this study was to examine the effect of exogenous progesterone in combination with a luteotrophic agent on corpus luteum survival and conceptus development in cross-bred beef heifers. Results may provide the basis for a strategy to elevate progesterone and improve fertility.
Canine oocytes are ovulated at the GV/GVBD stage and rely on CCs to mature to MII stage. Consequently, the role of CCs is very likely to be more important than in other species. The objective was to identify the relationship between oocytes and cumulus cells during oocyte maturation. The results demonstrated that cumulus cells play key roles in supporting oocyte maturation to the MII stage.
This study supplies a new predictor for poor ovarian response (POR) in the in vitro fertilisation field. We investigated the association of low basal androgen levels and IVF outcomes in a large Chinese population, and found low basal testosterone (<0.88 nmol L–1) was an independent risk factor for POR. This finding may help to identify young patients at high risk of POR.
Lipid pathways play important biological roles in mammalian embryology. We document a new strategy to analyse bovine oocytes and embryos, and provide a chemical image using MALDI-MSI technology. Results obtained in this work demonstrates that a combination of MF, MSI features and chemometric analysis can be applied to discriminate cell stages, characterising specific biomarkers and relating them to developmental pathways.
The movement of numerous proteins between the cytoplasm and nucleus is essential to remodelling. In this study, the exchange of histone between the cytoplasm of the oocyte (H1foo) and the transferred nucleus (H1c) is shown to be essential to somatic cell nuclear transfer in buffalo.
N-3 PUFAs are beneficial to human health, and increasing the amount of n-3 PUFAs in mammals by introducing sFat-1 gene will improve the animal meat quality. This study was undertaken to produce sFat-1 transgenic rabbit by ICSI, and found that sFat-1 transgenic rabbits exhibited an ~10-fold increase in n-3 PUFAs in muscles. It will be possible to produce a new transgenic rabbit breed with high n-3 PUFAs.
Improving the quality of preimplantation embryos is imperative in human in vitro fertilisation since the birth of the first baby in 1978, and high fragmentation is one of the limiting factors. This study links the phenomenon of human embryo fragmentation with energy homeostasis, mitochondrial dynamics and oxidative phosphorylation, suggesting altered transcriptional profiles of mitochondria-encoded components. A better understanding of the molecular mechanisms underlying these processes may help improve the energy capacity of the early embryo.
The vaginal cul-de-sac, which is unique to the reproductive tract of marsupials, is thought to play an important role in reproduction, as the volume of fluid in the cul-de-sac increases up to ovulation and diminishes thereafter. Generally, changes in fluid volume in the reproductive tract are a result of changes in the transport properties of the epithelial lining. Our findings describe an epithelial transport mechanism responsible for absorption of fluid from the cul-de-sac following ovulation.
N-glycans (oligosaccharide chains linked to proteins by the amino group of an asparagine) essentials for mammalian spermatogenesis have been identified. Here, for the first time the presence of N-glycans in the testis of the amphibian Xenopus laevis has been analysed by lectin histochemistry. The functional role of these glycans could be related to the role of N-glycans involved in mammalian spermatogenesis.
Clarifying the mechanism for acquisition of developmental competence in bovine oocytes is important for improving the in vitro production system. Relationships between developmental competence and mitochondrial activity of in vitro-grown oocytes during meiotic arrest immediately before IVM culture were investigated. Mitochondrial activity at 10 h after starting meiotic arrest was highest and those oocytes showed comparable developmental competence with in vivo-grown oocytes.
Resistin is a small cysteine-rich protein, produced by adipose tissue and involved in insulin resistance, type 2 diabetes and reproduction. The findings of this study suggest that there is local cooperation exists resistin and PPARγ expression in the porcine ovary; resistin significantly increases PPARγ expression, whereas PPARγ decreases resistin expression. PPARγ is a new key regulator of resistin expression and function.
Although glutamate signalling is traditionally investigated in the context of the central nervous system, it could also play a role in non-neuronal tissues. Herein, we investigated the expression of group III metabotropic glutamate (mGlu) receptors in the reproductive system of male mice. Based on findings for the mGlu7 receptor, we postulate that constitutively expressed mGlu receptors in the male reproductive system may influence male fertility.
Superovulation adversely influences oocyte maturation and early embryo development, but how superovulation results in these disturbances has not been clearly addressed yet. In this study, we aimed to determine the effect of superovulation on expression of embryonic poly(A)-binding protein (Epab) and poly(A)-binding protein, cytoplasmic 1 (Pabpc1) genes. We found that superovulation significantly alters Epab and Pabpc1 gene expression in mouse oocytes and early embryos.
Colostrum, apart from its crucial role for neonate survival, serves as a conduit for the transmission of signalling molecules from the mother to offspring. Maternal nutrition during late gestation affects colostrum composition and immune factor content, which through immunomodulatory properties, alters immune system function in the offspring. Events during fetal or neonatal life may have programming effects on immune function in later life.