Interleukin-6 stimulates in vitro development of late-stage ovine embryos.

The effect of interleukin-6 (IL-6) supplementation during the different phases of in vitro embryo culturing (IVC) on embryo development and embryonic gene expression was studied in ovine. IL-6 was added to IVC medium during the late phases (72-192 h; 5, 10, and 25 ng/ml IL-6) or entire period (0-192 h; 10 ng/ml IL-6) of IVC to determine its effect on embryo development. Further, the effect of IL-6 (10 ng/ml) supplementation at the 72 h of IVC on gene expressions associated with JAK/STAT signalling and pluripotency in 8-16 cell embryos (1 h post-supplementation) and compact morulae (48 h post-supplementation), and apoptosis and primitive endoderm (PrE) development in compact morulae was investigated.

An Efficient Nitroblue Tetrazolium Staining and Bright-Field Microscopy Based Method for Detecting and Quantifying Intracellular Reactive Oxygen Species in Oocytes, Cumulus Cells and Embryos.

Assessment of intracellular reactive oxygen species (ROS) is important for evaluating the developmental ability of cumulus-oocyte complexes (COC) and embryos. Although, fluorescence-based 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining method is used widely for detecting intracellular ROS in COC and embryos, it is associated with several limitations. This study aimed to develop an alternative method for detecting and quantifying intracellular ROS in oocytes, cumulus cells and embryos based on nitroblue tetrazolium (NBT) staining and bright-field microscopy.

IGF-1 treatment during maturation improves developmental potential of ovine oocytes through the regulation of PI3K/Akt and apoptosis signaling.

This study aimed to assess the effect of the insulin-like grow factor 1 (IGF-1) treatment during maturation on the gene expression and developmental ability of ovine oocytes. Ovine cumulus-oocyte complexes (COC) were matured without (control) or with the supplementation of IGF-1 (100 ng/ml) and then subjected to fertilization and culture. The rate of oocyte maturation and embryo development was recorded and expression of the selected genes (involved in the PI3K/Akt and apoptosis signaling) was assessed in the matured oocytes.

Interleukin-7 improves in vitro maturation of ovine cumulus-oocyte complexes in a dose dependent manner.

Interleukin-7 (IL-7) mediated signals are linked to development, proliferation, survival and differentiation of cells. Recent evidences indicate its role in oocyte maturation process as well. Nevertheless, the underlying mechanisms of IL-7 involvement in oocyte maturation are not well characterized.

Temporal expression of cumulus cell marker genes during in vitro maturation and oocyte developmental competence.

Purpose: Cumulus cells (CC) play important roles in oocyte development and cumulus expressed genes can be used as markers for oocyte quality. This study aimed to investigate temporal changes in the expression of cumulus marker genes during oocyte maturation as possible biomarkers of embryo developmental competence in ovine.

Methods: Gene expression was assessed in the CC of the BCB+ (developmentally competent) and BCB- (developmentally poor) oocytes at 0, 12, and 24 h of in vitro maturation (IVM).