Reproduction, Fertility and Development
Number 8 2013
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.
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.
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.
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.
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.
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.
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.
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.
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 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.
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.
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.
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.
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.