Supplementation of l-carnitine during in vitro maturation improves embryo development from less competent bovine oocytes.

The present study was designed to define the impact of l-carnitine, supplemented during maturation, on bovine oocytes with different meiotic competence in terms of their IVF outcomes. Meiotically more competent (MMC) and less competent (MLC) oocytes were obtained separately from differently sized follicles at selected phases of folliculogenesis. The oocytes were matured with or without l-carnitine, fertilized and cultured to the blastocyst stage.

Energy Status Characteristics of Porcine Oocytes During In Vitro Maturation is Influenced by Their Meiotic Competence.

The characteristics of energy status in porcine oocytes as related to their meiotic competence and in vitro maturation were studied. Cycling pubertal gilts in the early luteal to early follicular phases of the ovarian cycle were used as oocyte donors. The oocytes recovered from medium (MF) or small follicles (SF) were considered meiotically more or less competent, respectively.

Characteristics of bovine oocytes with different meiotic competence in terms of their mitochondrial status and expression of nuclear-encoded factors.

The present study was designed to characterize bovine oocytes with different meiotic competence and atresia levels in terms of their mitochondrial status. Oocyte subpopulations were recovered either from medium (MF) or small (SF) follicles and categorized as healthy, light-atretic and mid-atretic according to oocyte morphology. Mitochondrial activity, morphology and distribution, adenosine triphosphate (ATP) content and expression of mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF1) were assessed before (GV) and after (MII) maturation.