Supplementation of sperm cryopreservation media with H2S donors enhances sperm quality, reduces oxidative stress, and improves in vitro fertilization outcomes.

Cryopreservation of sperm can cause oxidative stress and damage, leading to decreased different functional parameters and fertilization potential. In this study, we evaluated two types of H2S donors: NaHS, a fast-releasing donor, and GYY4137, a slow-releasing donor during cryopreservation of goat sperm. Initially, we determined that 1.5 and 3 µM NaHS, and 15 and 30 µM GYY4137 are optimal concentrations that improved different sperm functional parameters including motility, viability, membrane integrity, lipid peroxidation, and ROS production during incubation at 38.5 °C for 90 min. We subsequently evaluated the impact of the optimal concentration of NaHS and GYY4137 supplementation on various functional parameters following thawing during cryopreservation. Our data revealed that supplementation of extender improved different parameters including post-thaw sperm motility, viability, membrane integrity, and reduced DNA damage compared to the frozen-thawed control group. The supplementation also restored the redox state, decreased lipid peroxidation, and improved mitochondrial membrane potential in the thawed sperm. Finally, we found that supplementation of the extender with NaHS and GYY4137 enhanced IVF outcomes in terms of blastocyst rate and quality of blastocysts. Our results suggest that both donors can be applied for cryopreservation as antioxidants to improve sperm quality and IVF outcomes of frozen-thawed goat sperm.

Ferulago angulata extract improves the quality of buck spermatozoa post-thaw and counteracts the harmful effects of diazinon and lead.

During cryopreservation, spermatozoa are exposed to chemical or physical stress that has adverse effects on the quality of mammalian spermatozoa. Recently, much attention has been paid to environmental contaminants (ECs) in livestock, because of their detrimental effects on livestock productivity and fertility. ECs like diazinon (DZN) and lead acetate (LA) are considered ubiquitous and induced oxidative stress, which decreases spermatozoa quality. Since Ferulago angulata extract (FAE) has antioxidant properties, the present study investigated the effect of FAE supplementation in a freezing extender, in the presence or absence of DZN + LA, during cryopreservation, on the quality and fertility ability of buck spermatozoa after thawing. Pooled ejaculates were diluted with a freezing extender and supplemented with FAE (0.002%, w/v) in the presence or absence of DZN (100 µM) + LA (12.5 µM). Post-thaw spermatozoa parameters, ROS production, fertilization ability, and developmental competence of oocytes inseminated with FAE/DZN + LA treated spermatozoa were calculated. The results demonstrated that FAE improves cryopreserved spermatozoa motility, viability, membrane integrity, fertilizability, and developmental competence, and reduced spermatozoa ROS production in the presence or absence of DZN + LA. Besides, FAE significantly restored the adverse effects of DZN + LA exposure during cryopreservation on inner cell mass (ICM) count, trophectoderm (TE) cell count, total cell number (TCN), and the ratio between ICM to TCN. In conclusion, FAE on its own resulted in an improvement in the buck spermatozoa's quality and fertility. Therefore, the addition of FAE, as a natural antioxidant to buck semen extender, can increase spermatozoa cryotolerance and post-thaw resistance even when exposed to ECs.

Functional characterization of NANOG in goat pre-implantation embryonic development.

Nanog as a novel pluripotent cell-specific gene plays important roles in regulation of signaling pathways for maintenance and induction of pluripotency in inner cell mass (ICM) and embryonic stem cells (ESC) in mouse. The molecular features and transcription regulation of NANOG gene in domestic animals are not well defined. In this study, we performed knockdown of NANOG mRNA in goat embryos and examined its effect on early embryonic development. Presumptive zygotes were injected with a volume of 8-10 pl NANOG or scrambled (SCR) siRNA, and subsequently cleavage and blastocyst formation rate were assessed. Furthermore, gene expression analysis was carried out in 6-8 cell and blastocyst derived embryos from non-injected controls, SCR - and siRNA-injected presumptive zygotes. Cleavage and blastocyst rates in siRNA groups were insignificantly lower than the control and SCR groups. Embryos with reduced expression of NANOG showed decrease in number of trophectoderm (TE) and total cells in blastocysts. Analysis of expression of developmentally important genes (SOX2, OCT4 and NANOG), which work as a network, showed that NANOG knockdown results in significant increase in expression of SOX2 and OCT4 and among the possible target genes (CDX2, REX1 and GATA4) of this network, only GATA4 showed increased expression. Our results suggest that NANOG is likely to be required for proliferation of trophoblastic cells.