Reproduction, Fertility and Development
Number 7 2015
Follistatin is a protein with key roles in the female reproductive system. We used mutant mouse strains to demonstrate the importance of follistatin in the postnatal development and function of the uterus and oviduct. Our work highlights the need to further examine the role of follistatin in the reproductive tract, as well as its key role in the ovary.
This research reports important improvements in prostate biology focusing on the mechanisms underlying the origins of diseases from the female prostate (Skene’s gland). Thus, the aim of this study was to evaluate the interferential effects of exogenous testosterone exposure during the prenatal and pubertal periods on the health of the female prostate. We observed that the exposure to androgenic disruptors may predispose the gland to develop lesions with aging.
Although it is commonly used in swine farms, heterospermic AI does not allow precise evaluation of boar fertility. The reproductive performance and the paternity contribution of four boars (A, B, C and D) were compared in this study using homospermic and heterospermic AI in 511 sows. Differences among boars were only identified after genotyping the piglets sired through heterospermic AI.
Ovarian cryopreservation for fertility preservation is a gold standard procedure in numerous cases, like childhood cancers, although it is still considered experimental. Vitrification is widely used in embryo and oocyte cryopreservation, but its effectiveness for ovarian freezing remains debatable. Slow freezing seems to preserve ovarian content better and therefore the vitrification of tissues needs to be improved by means of cryoprotective agents and carrying devices.
Nuclear progesterone receptor has two main isoforms, PGRA and PGRB, which have different functions. PGRB cDNA from cattle was cloned then mRNA and protein levels for both isoforms in corpora lutea during the oestrous cycle and first trimester of pregnancy were determined. The data suggest that the variable expression of these isoforms during the oestrous cycle may depend on the influence of progesterone.
Ovarian dynamics involve extensive cell-to-cell communication, requiring fine regulation of cell signalling. This led us to evaluate the expression patterns of Notch cell-signalling pathway component and effector genes during follicle and corpus luteum development. We found Notch signalling active, and Notch expression spatially and temporally associated with key events in follicle and corpus luteum development. This suggests a relevant regulatory role of Notch signalling in ovarian dynamics.
Computer-assisted sperm-motility analysis has been scarcely studied or used on amphibians. In this research we validated a standardised method producing reproducible results and compared traditional data analysis with sperm-subpopulation frequencies. We demonstrated that sperm-subpopulation frequency analysis can detect treatment effects on sperm motility.
Various dietary strategies to reduce piglet mortality have been tested, with increased fat in the maternal diet thought to improve energy partitioning to the fetus, subsequently improving neonatal outcome. However, we found that a maternal diet containing palm oil in place of starch led to reduced maternal glucose tolerance, increased neonatal mortality and altered gene expression in the liver at 1 week of age. Despite this, offspring from mothers fed the fat-substituted diet displayed no changes in postnatal growth or hepatic gene expression at 6 months of age.
The Amazonian manatee is a threatened aquatic mammal endemic to the Amazon basin and the species is a seasonal breeder. The aim of this study was to evaluate the effect of the season on the reproductive hormone levels of captive Amazonian manatees. Different from males, all female hormones levels showed seasonal variation. The results strongly suggest the existence of reproductive seasonality in Amazonian manatees, even in captive conditions; however, apparently only females exhibit reproductive quiescence during the non-breeding season.
The demand for the successful preservation of porcine embryos has increased in the past decade. In this study, we evaluated the effects of vitrification and warming, a widely used cryopreservation method, on the expression of six relevant genes in in vitro-produced porcine blastocysts. The results suggest that vitrification and warming affect embryo developmental ability and pluripotency by increasing the number of cells with fragmented DNA, peroxide levels and HSPA1A gene expression.
Studies about canine reproduction have increased over the years once this species can be used as a model for their endangered counterparts. This work aimed to reproduce in laboratory a similar hormonal condition in order to improve the results that are still far from satisfactory. Our results reveal that mimicking the hormonal changes is beneficial for oocyte maturation and so it is a more reliable approach to overcome the challenges of in vitro techniques.
The efficiency of animal cloning by somatic cell nuclear transfer (SCNT) is low because of incomplete nuclear reprogramming. We tried to prevent the mitochondrial and DNA damage caused by mechanical stress-associated reactive oxygen species during manipulation procedures of SCNT using antioxidants. Antioxidant treatment during manipulation procedures can efficiently prevent cellular damage and improve nuclear reprogramming.
Src family kinases are involved in the meiotic maturation of mammalian oocytes, but the information about their role in regulation of meiotic maturation has been mainly obtained from mouse oocytes. The present study proved that the Src family kinases play an active role in the meiotic maturation of porcine oocytes at least partly through MPF and MAPK activity regulation. Considering that data from mouse oocytes need not be validated in other species, our findings contribute to the understanding of the regulation of oocyte maturation.
Studies of endocrine-disrupting chemicals (EDCs) in egg-laying reptiles have significantly advanced knowledge in this field; however, 30 % of reptiles are live-bearing. We examined the effects of feminising EDCs by exposing female Niveoscincus metallicus to the synthetic oestrogen, diethylstilbestrol, and found that gonadal development of male and female neonates from exposed mothers was impaired at birth. Maternal exposure to feminising EDCs may have profound consequences on reproductive fitness.
The presence of non-enzymatic antioxidants in the environment surrounding the embryo reduces oxidative stress. Thus, the present study sought to determine how the addition of l-ascorbic acid during culture and vitrification and warming affects quality and gene expression of in vitro produced porcine blastocysts. Results obtained indicate that l-ascorbic acid supplementation increases embryo survival following cryopreservation via decreasing HSPA1A levels.