Reproduction, Fertility and Development
Number 5 2017
Glucocorticoids (GCs) sustain life and the development of human embryo; however, fetoplacental exposure to high maternal GC levels may lead to placental and fetal abnormalities, with the adverse consequences of GC excess manifested later in life. The mechanisms through which GC excess alters placental and fetal development are yet to be identified; however, changes in placental GR levels and subcellular localization and ratios may modify placental function, in utero growth of the fetus and lifelong health.
Gestational iron deficiency can cause developmental programming of adult hypertension, but the critical developmental window during nephrogenesis has not been studied. The present study examined renal development during perinatal iron deficiency in rats and found altered timing of kidney maturation and histological renal adaptations that may contribute to dysfunctional glomeruli and renal hyperfiltration, which themselves contribute to hypertension.
Information about follicle density is critical to determine the quantity of fragments during biopsy procedures in women and domestic animals. This study evaluated the effects of age and determined the minimum number of ovarian fragments and histological sections required to estimate equine follicle density in ovarian biopsy fragments. The results show that follicle density is negatively influenced by increasing age and, independent of follicle heterogeneity, three to four ovarian fragments combined with 65 histological sections are required to accurately determine follicle density in equine ovarian tissue.
Metabolic imbalance impairs female fertility. We wanted to find out how metabolism affects bovine oocyte quality, and demonstrated that insulin exposure during in vitro oocyte maturation affects embryo development, morphology and gene expression. Even short-term exposure to a metabolic imbalance has lasting effects on embryo development, and this metabolic programming may have consequences later in life.
In vitro-derived bovine embryos frequently exhibit lipid accumulation, mitochondrial dysfunction and enhanced levels of reactive oxygen species. With the aim of unravelling the role of the AMP-activated protein kinase cytalytic subunit 1alpha (AMPKα), the present study identified AMPKα activity and distinct expression patterns of AMPKα-related genes to be correlated with that phenotype. These results prove the important role of AMPKα in embryonic energy metabolism.
Finding novel biomarkers of ovarian follicle function would be of benefit. This study investigated the follicle biomarker potential of microRNAs (miRNAs) and found that levels of miR-873 and miR-202 can be used as indicators of steroidogenic capacity in cattle. These miRNAs, in addition or alternatively to commonly used steroid level measurements, could be used to accurately classify follicles based on steroidogenic capacity.
Bone marrow chimerism is a unique and normal feature of Callithrichidae development that originates through shared placental circulation. A new X and Y chromosome-specific fluorescent in situ hybridisation protocol for Callithrix jacchus has been developed and validated to detect and investigate chimerism between male and female littermates. One of the strengths of this method is that it is useful in interphase cells, and allows cell morphology to remain intact to facilitate identification of cell type.
Most species of Australasian old endemic rodents have a highly complex sperm head morphology that contains an apical hook together with two ventral processes of variable length and orientation. This study tested whether this variation is a sexually selected trait using relative testes mass as a proxy for the intensity of inter-male sperm competition and controlling for phylogeny. The angle of these processes, but not length, was positively correlated with relative testes mass; its possible functional significance is briefly discussed.
For the first time, a minimal invasive method that allows ovarian tissue collection from sows is described in detail. This method, a transvaginal ultrasound-guided biopsy, is quick, can be performed by one person, and has no major effects on the sow’s reproductive performance. It can be applied on the farm to study effects of housing or nutrition on luteal function.
Dietary PUFA and vitamin E are known to influence sperm morphology and oxidative stress. The effects of dietary n-6 : n-3 and vitamin E on the sperm morphology and oxidative stress in boars were investigated. An n-6 : n-3 ratio of 6 :1 and 400 mg kg–1 vitamin E have beneficial effects on sperm morphology by improving oxidative stress.
Cloned concepti on Day 225 of gestation were characterised by lower pregnancy rates, high gestational losses, a distinctive biphasic growth pattern, with early growth restriction followed by accelerated growth and foetal weight on Day 225, and significant morphological changes in placental mass and shape when compared with in vivo-derived pregnancies. Conversely, Day-225 IVF-derived concepti were widely similar to controls.
In vitro manipulation of oocytes is a standard procedure used in assisted reproduction. The aim of the present study was to analyse the effect of suboptimal culture temperatures on various aspects of meiotic division, including chromosomal congression and segregation defects. The results revealed that even a small deviation from optimal culture temperature has a marked effect on chromosome congression and aneuploidy.
The uterus produces steroids and primary steroidogenic enzymes are expressed in the uterus of pregnant and cyclic pigs. In this study we examined 17β-hydroxysteroid dehydrogenase expression and the effects of LH, FSH and prolactin on oestrone and 17β-oestradiol release in vitro in endometrial explants. We show that LH, FSH and prolactin may regulate oestrogen release by the endometrium.
The physiological functions of prion and prion-like proteins are overlapped by their pathological features, namely in the invariably fatal neurodegenerative diseases of both humans and animals, such as Kuru, Creutzfeldt-Jakob disease and new variant, bovine spongiform encephalopathy and sheep scrapie. The aim of the present study was to investigate the role of the prion-like Doppel (PRND) protein and different PRND genotypes in the sperm capacitation process, cryoresistance, and fertility potential. Both factors were crucial for sperm capacitation potential, cryoresistance, and embryo production. Thus, an important physiological function of Doppel protein and genotype in male fertility has been demonstrated.
We are in need of safe, effective and affordable male contraceptives. Indazole carboxylic acids such as lonidamine and adjudin disrupt adhesion between Sertoli and germ cells in the rat testis, resulting in infertility. One of the key findings of this study was that lonidamine-ethyl ester also displayed contraceptive effects. Additional studies are required to determine whether indazole carboxylic acids can enter the clinical pipeline
Tamoxifen is widely used in the treatment of breast cancer and can interfere with the reproductive system. The present study showed that tamoxifen administration during the neonatal period has oestrogenic actions on oestrogen-sensitive nuclei in the brain controlling the reproductive axis in female mice. Therefore, tamoxifen may have adverse effects on brain differentiation and reproductive function.
Prostaglandins induce contraction and relaxation of oviductal smooth muscle, which are essential for transport of gametes and embryo. The present results demonstrate that lysophosphatidic acid significantly stimulated prostaglandin production by cultured isthmic stromal cells. It is suggested that locally produced lysophosphatidic acid contributes to oviductal motility in the isthmus by regulating prostaglandin production in cows.
The hormone oestrogen is essential for testis development and its synthesis is dependent on the enzyme aromatase. However, the molecular mechanism of aromatase regulation is still poorly understood. This study describes for the first time the cellular localisation of proteins important for aromatase regulation, which are well known in breast tissue, in the normal testis. This new finding may help develop new therapies for oestrogen-mediated infertility.
Stallion spermatozoa lose viability and fertilising capability relatively quickly when cooled; robust spermatozoa can be selected by colloid centrifugation. In the present study, selected spermatozoa were shown to metabolise differently to controls, producing less hydrogen peroxide, which is known to damage spermatozoa. These results indicate that colloid centrifugation could be used to improve the quality of stallion semen for AI.
Among the family of engineered nanostructures, cerium dioxide nanoparticles (CeO2 NPs) are receiving particular attention for their antioxidant properties with potential applications in biomedical therapies. This study examined the effect of supplementation with different doses of CeO2 NPs during in vitro maturation of prepubertal ovine oocytes on their embryonic development. Low concentration of CeO2 NPs increased development to blastocyst stage and embryo quality.