Optimizing swine in vitro embryo production with growth factor and antioxidant supplementation during oocyte maturation.

Porcine in vitro fertilization often results in low embryo development rates compared to other livestock species, which is often associated with either a low fertilization rate or high incidence of polyspermy. Since the quality of oocyte maturation is known to play a significant role in oocyte competence, we investigated the impact of supplementing in vitro maturation (IVM) medium containing porcine follicular fluid (pFF) with the growth factors FGF2, LIF and IGF1 (FLI), along with different combinations of cysteine, melatonin and ITS, on cumulus cell expansion, oocyte meiotic maturation, fertilization outcome, embryo development and blastocyst cell numbers. Maturation medium containing pFF yielded the greatest cumulus expansion. Compared to pFF and FLI individually, using pFF and FLI together resulted in the best embryo development rates over total oocyte placed in IVF (12.5% vs. 15.0% vs. 26.6%, respectively). Supplementation of IVM medium containing pFF and FLI with either cysteine, melatonin or insulin-transferrin-selenium, revealed that cysteine was essential to improve embryo development, while melatonin and ITS had a limited impact on improving blastocyst rates. Finally, we observed that pig oocytes matured in medium supplemented with pFF, FLI, cysteine and melatonin had a high proportion of monospermic zygotes (68.2%) and low proportion of polyspermic zygotes (15.9%) following IVF and yielded superior cleavage (78.2%) and blastocyst (32.0%) rates.

Supplementation of oleic acid, stearic acid, palmitic acid and ß-hydroxybutyrate increase H3K9me3 in endometrial epithelial cells of cattle cultured in vitro.

There is growing evidence that greater than homeostatic blood concentrations of nonesterified fatty acids (NEFAs) and ß-hydroxybutyrate (BHBA) have negative consequences on dairy cow's fertility, but effects on cell homeostasis in the reproductive system is not completely understood. In this study, lipids accumulation, reactive oxygen species (ROS) concentrations, abundance of gene transcripts, and immunofluorescence signal of H3K4me3 and H3K9me3 were evaluated in endometrial epithelial cells of cattle cultured with NEFAs (Oleic (OA), Stearic (SA) and Palmitic (PA) acids), BHBA, NEFAs + BHBA or each of the three NEFAs alone. The cellular lipids were in greater concentrations as a result of NEFAs + BHBA, NEFAs, SA or OA supplementation, but not by BHBA or PA. The ROS concentrations were greater when there were treatments with NEFAs + BHBA, NEFAs or BHBA. The relative mRNA abundance for genes involved in the regulation of apoptosis (XIAP), glucose transport (GLUT3), and DNA methylation (DNMT1) were greater when there were NEFAs + BHBA, but not NEFAs, BHBA, OA, SA or PA treatments. The immunofluorescence signal for H3K9me3 was greater when there were NEFAs + BHBA, NEFAs or PA, but not by BHBA, OA or SA treatments. These findings indicate that NEFAs and BHBA have an additive effect on endometrial cells of cattle by altering epigenetic markers and the expression of genes controlling important cellular pathways. Furthermore, there was cellular lipid accumulation and increased H3K9me3 in cultured bovine endometrial cells that was mainly induced by OA and PA treatments, respectively.