Reproduction, Fertility and Development
Number 6 2012
Fibroblast growth factor (FGF) 8 functions as a mitogen and morphogen in a variety of cell types in vertebrate developmental processes. In the present study, we found that Xenopus SRY (sex-determining region Y)-box 2 acts as a transcription factor via direct interaction with the upstream region of the Xenopus FGF8 (XFGF8) gene in developing Xenopus embryos. Thus, our results provide an additional mechanism of XFGF8 gene regulation in early Xenopus development.
Several studies demonstrated a negative effect of subclinical endometritis on bovine reproductive performance, the mechanisms, however, remained unclear so far. Therefore our study tested the hypothesis that subclinical endometritis alters the endometrial or embryonic gene expression profile. As a result, the present data demonstrate that bovine subclinical endometritis alters the endometrial transcriptome dynamic within the oestrous cycle and results in distinct changes of the endometrial and embryonic gene expression profile.
Most organisms have developed a biological clock, synchronised with the surrounding environment, located in the pineal gland that acts as a photo-transducer conveying the environmental photic information to the brain via the release of melatonin, a powerful multifunctional hormone. This study demonstrates the ability of melatonin improving killifish' breeding efficiency playing an important role in the complex network of signals that centrally/locally control reproduction overall. The results obtained may be used in the reproductive biotechnologies of farmed species.
The negative consequences of obesity on reproduction are increasingly apparent and are of great concern given the incidence of obesity among people of reproductive age. It is not understood how obesity impacts fertility; consequently we investigated the effect of obesity on early embryo quality prior to implantation in the present study. Both male and female obesity compromised embryo development and quality, which may account for the decrease in reproductive fitness.
Chromatin structure is globally remodelled during embryo development and perturbations in chromatin structure are associated with aberrant embryo development. We found that inhibition of euchromatic histone-lysine N-methyltransferase 2 (EHMT2), a histone methyltransferase, leads to changes in global patterns of histone methylation and compromises embryo development. Our results suggest that even transient alterations in histone methylation patterns can have lasting effects on embryo development, highlighting the importance of understanding how chromatin structure is controlled during embryo development.
The seasonal infertility period in sows is the most economically important reproductive problem for pig producers. Significantly, there is an increase in pregnancy loss during this time. This review summarises recent advancements made in our understanding of the mechanisms that contribute to this reduced fertility. With emphasis on seasonal variation in ovarian function and its influence on subsequent fertility, there is clear evidence that reduced oocyte developmental competence contributes to seasonal infertility. With this new information in mind, researchers and producers can now devise strategies to overcome the seasonal infertility phenomenon.
Although the uterine circulation must enlarge considerably during pregnancy to ensure normal fetal development, the mechanisms responsible are unknown. We developed a new surgical procedure to determine whether uterine stretch alone can stimulate vascular growth, and found that it did indeed induce both lengthening and widening of uterine vessels. This discovery opens a new avenue of investigation into the underlying molecular signals and pathways that regulate uterine vascular enlargement in normal versus diseased (e.g. intrauterine growth restriction, preeclampsia) pregnancy.
Evaluation of egg quality is one of the main bottlenecks in aquaculture where high-quality eggs are required for effective commercial production and scientific research aimed at improvement of breeding procedures. We investigated the course of the cortical reaction in pikeperch eggs where noticeable and violent deformation of chorion could be observed shortly (3–5 min) after their activation. On the basis of the results obtained we have established a protocol for egg quality evaluation in this species according to the deformation rate of eggs following activation with water.
Stress is a consequence of modern life and can also be correlated with many perinatal and postnatal diseases. Herein, we analyse the influence of stress in maternal, placental and fetal weight of pregnant rats, placental morphology and expression of vascular-associated factors. Our results show relevant differences in the mother’s blood pressure, placental structure and offspring weight highlighting the complex and multifactorial biological processes, which can be associated with stress and contribute to understanding the importance of stress in pregnancy disorders.
Large amounts of alcohol consumption during pregnancy can affect the health of the fetus and subsequent offspring. But do small amounts of fetal alcohol exposure have similar effects? We have developed a model of chronic low-dose maternal alcohol consumption in the rat and found that this restricts fetal growth and slows growth in adult male offspring. We will now use this model to determine whether low amounts of fetal alcohol exposure result in adult disease states, such as hypertension or diabetes.
The oviduct protected the sperm DNA integrity for adequate embryo development. This study showed an increase in spermatozoa with DNA damage in co-incubation with tubal explants from the ampullar region but not from the isthmal region. The isthmal region is protected against sperm DNA damage induced by oxidant molecules, as it constitutes a sperm reservoir necessary for normal fecundation.
This is the first study to address the male reproductive biology of Spix’s yellow-toothed Cavy (Galea spixii). The aim of this study was to evaluate the phases of sexual development and spermatogenesis in this specie. It may be classified into the following phases: from birth to the age of 15 days (immature); 30 days of age (pre-pubertal); 45 to 105 days of age (pubertal); and 120 and 150 days of age (post-pubertal).
In female pigs, nutrition during both early and late antral follicle development affects ovulation rate and the number of embryos, but the interaction has not been properly studied. The current study indicated that undernutrition during early antral follicle development has irreversible effects on subsequent reproduction. The finding emphasises the importance of adequate nutrition during late lactation in sows and one to three weeks before mating in gilts.