Bilateral regulation of embryo development can exist in the cow, although the mechanism remains basically unexplored. In uterine fluid, hexoses and proteins related to embryo development, but not to embryonic sex, were found to change between left and right uterine horns. These discoveries may lead to a better understanding of uterine physiology, fertility and bilateral pregnancy regulation.
Reproduction, Fertility and Development
Volume 26 Number 4 2014
Although conjugated linoleic acids (CLA) are employed frequently in dairy cow nutrition, their effects on the bovine preimplantation embryo have not been fully assessed so far. In the present study an effect of CLA and the carrier substance DMSO on morphological and molecular bovine embryo quality was detected in an in vitro model. This suggests that effects evoked by CLA might result in altered early embryonic development.
RD12403A diet enriched in linoleic acid compromises the cryotolerance of embryos from superovulated beef heifers
This study evaluated the production and cryotolerance after freezing or vitrification of embryos from superovulated Nelore heifers supplemented with rumen-protected polyunsaturated fatty acids (PUFA). Heifers kept in pasture were supplemented in a crossover design with either PUFA (predominantly linoleic acid; n =40) or a fat-free supplement with additional corn (n = 40) before superovulation. Dietary PUFA rich in linoleic acid did not improve embryo production, but compromised the cryotolerance of frozen or vitrified embryos.
The existence of wild wood bison is threatened by tuberculosis and brucellosis introduced more than 90 years ago by domestic cattle. We developed a technique for synchronizing ovarian activity among bison as a necessary step in establishing a bio-bank of disease-free embryos that could be used to restore once populous herds. This is the most recent of our studies focused on establishing reproductive technologies to facilitate repopulation of the largest land mammal in the Americas.
This study evaluated superovulatory responses and in vivo embryo production in 33 Nelore cows treated with FSH starting at 1 (D1) or 2 (D2) days after ovum pick-up (OPU). Cows in Group D2 cows had a greater superovulatory response (18.9 vs 9.1 corpora lutea; P < 0.03) and more freezable embryos (3.2 vs 1.3; P < 0.05) than Group D1 cows. Therefore, it is recommended to wait at least 2 days before starting superovulatory treatment with FSH after OPU.
Gonocytes are primitive germ cells responsible for the production of spermatozoa in male testes. The objective of this study was to identify a cell surface marker for gonocytes in pigs. The findings from this work will not only help to elucidate the characteristics of gonocytes, but also to facilitate their subsequent manipulation.
RD12302Actions of oestradiol and progesterone on the prostate in female gerbils: reversal of the histological effects of castration
This study evaluated the effects of oestradiol (E2) plus progesterone (P4) administration on the prostate of castrated female gerbils using histological and immunohistochemical techniques. Treatment of castrated gerbils with E2 + P4 restored the secretory activity and morphological structure of the female prostate. These findings may indicate a synergistic action of E2 and P4 in maintaining healthy prostate physiology, and may also lead to the development of treatments for important prostate diseases.
In our study, we investigated the transcriptional profile and role of WNT3A signaling in maintaining the pluripotency of buffalo embryonic stem (ES) cells as well as in inducing their differentiation. We concluded that WNT3A, in combination with exogenous FGF-2 and LIF, induced proliferation of undifferentiated ES cells, while differentiation studies revealed its role in causing formation of scaffold-like structures and preventing differentiation into neuron-like cells. Thus, WNT3A signalling pathway is necessary both for maintaining pluripotency and for directed differentiation of buffalo ES cells.
RD13010Post-ovulatory ageing of mouse oocytes affects the distribution of specific spindle-associated proteins and Akt expression levels
A drastic decrease of oocyte viability and fertilisability occurs during post-ovulatory ageing (POA). The aim of this study was to determine if POA could impair oocyte quality by altering the expression level or localization of proteins implicated in cell survival and chromosome segregation. Aged oocytes showed altered distribution of some spindle-associated proteins and a decrease in both H3S10 phosphorylation and Akt expression levels. All these events could impair fertilization by inducing oocyte apoptosis.
RD13004Embryo development and sex ratio of in vitro-produced porcine embryos are affected by the energy substrate and hyaluronic acid added to the culture medium
It is widely known that the energy substrate and hyaluronic acid added to the culture medium of porcine in vitro-produced embryos influence their development. The aim of the present study was to determine the putative synergistic effects of glucose or pyruvate–lactate and hyaluronic acid on embryo development, as well as on the sex ratio. Interestingly, high concentrations of hyaluronic acid decreased blastocyst rates in both energy substrate groups, but only affected the sex ratio of embryos cultured with pyruvate–lactate.
Bacterial infections pose a serious risk for ongoing pregnancy, but can also have a great impact on fecundity. By using an animal model to investigate the influence of the major bacterial components lipopolysaccharide (LPS) and peptidoglycan (PGN) on pregnancy, we discovered that LPS and PGN induce different types of reproductive failures. Our animal model can serve as a valuable tool to gain a better understanding of the factors underlying infection-induced pregnancy complications in humans.
RD12380The novel porcine gene early growth response 4 (Egr4) is differentially expressed in the ovaries of Erhualian and Pietrain pigs
Reproductivity is one of the most important traits in pig production but has low heritability, so the genetic characterisation is more and more important. The aim of the work is to identify the genes that might affect the high reproduction rate of Erhualian pig. In the present study, differential gene expression was identified in the ovaries between Erhualian and Pietrain pigs, and Egr4 was evaluated as a novel candidate gene for porcine reproductivity.
RD13105Insulin-like growth factor and insulin-like growth factor-binding proteins in the bovine uterus throughout the oestrous cycle
The insulin-like growth factor (IGF) system of ligands and binding proteins constitute a complex regulatory system on which many aspects of reproduction and embryo growth are dependent. Very little is known about uterine IGF-1 and binding proteins (IGFBP) and how these are affected by stage of cycle and concentration of progesterone. This study indicates that uterine concentration of IGF-1 and IGFBP in cattle differ from that of plasma and suggest that they are under dynamic control throughout the oestrous cycle.
RD12059Spermatozoa from mice deficient in Niemann-Pick disease type C2 (NPC2) protein have defective cholesterol content and reduced in vitro fertilising ability
The cholesterol content of the sperm membrane is regulated in the epididymis. In this study we analysed the role of the epididymal cholesterol transport protein Niemann-Pick disease, type C2 (NPC2) protein in male fertility using genetically engineered NPC2-deficient mice. Spermatozoa from NPC2-deficient mice had less cholesterol and a reduced ability to fertilise eggs in vitro. These results could have important implications in the understanding of mammalian reproductive physiology and human infertility.