BACKGROUND Adiponectin is an adipokine, mainly produced by adipose tissue. It regulates several reproductive processes. The protein expression of the adiponectin system (adiponectin, its receptors, AdipoR1 and AdipoR2 and the APPL1 adaptor) in bovine ovary and its role on ovarian cells and embryo, remain however to be determined. METHODS Here, we identified the adiponectin system in bovine ov...

The adenosine monophosphate-activated protein kinase (AMPK) activators, 5'-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) and metformin (MET), inhibit resumption of meiosis in bovine cumulus-enclosed oocytes (CEO) and denuded oocytes (DO). The objectives of this study were to: (1) examine the effects of AMPK inhibitors on bovine oocyte meiosis in vitro; and (2) determine if AICAR or ...

Immature oocytes benefit from nutrient modification of the follicular environment by the surrounding cumulus mass. However, the oxygen concentration that the oocyte may be exposed to could be lower than the antral follicular concentration due to the metabolism of surrounding cumulus cells. Using metabolic data previously determined, we have developed a mathematical model of O(2) diffusion acros...

In mammals, oocyte acquires a series of competencies sequentially during folliculogenesis that play critical roles at fertilization and early stages of embryonic development. In mouse, chromatin in germinal vesicle (GV) undergoes dynamic changes during oocyte growth and its progressive condensation has been related to the achievement of developmental potential. Cumulus cells are essential for t...

Energy balance is regulated by ghrelin that is a neuroendocrine modulator. Ghrelin is expressed in reproductive organs. However, the role of ghrelin during in vitro maturation and bovine preimplantational development is limited. The purpose of this study was to determine the expression of ghrelin (GHRL) and its receptor growth hormone secretagogue receptor 1A (GHS-R1A) mRNA expression, and cumu...

Abstract Background The developmental competence of oocyte derived from in vitro maturation (IVM) is significantly lower than those matured vivo. Rapamycin an immunosuppressive substance and widely used to prolong the survival preserve cells culture. objective this research was explore whether rapamycin supplementation during IVM enhances meiotic maturation, quality, subsequent embryonic develo...

The objective of the research was to evaluate effect vitrification temperatures (VTs) and concentration cryoprotective agents (CPAs) on cytoskeleton bovine immature oocytes (BIOs). Bovine cumulus oocyte complexes (COCs) were collected divided randomly into five groups: (a) fresh control group, (b) vitrified in liquid helium (LHe; −269◦C with 5.6 M CPAs, (c) LHe (−269◦C 6.6 (d) nitrogen (LN; −19...

The oocyte is a key regulator of ovarian folliculogenesis and early embryonic development. However, the composition of the oocyte transcriptome and identities and functions of key oocyte-specific genes involved in the above processes are relatively unknown. Using a PCR-based cDNA amplification method (SMART technology), we constructed a bovine oocyte cDNA library. Analysis of 230 expressed sequ...

High environmental temperatures during the hot months of the year reduce reproductive performance in cattle. Summer heat stress depression in fertility is a multifactorial problem; however, there is evidence that the bovine germinal vesicle and maturing oocyte, as well as the early embryo, are major targets of the deleterious effects of heat stress. Such adverse effects are less pronounced in h...

Fertilisation by intracytoplasmic sperm injection (ICSI), a technique that bypasses the membrane fusion of the gametes, has been widely used to produce offspring in humans and mice. Success with this technique has lent support to the hypothesis that in mammalian fertilisation, a factor from the sperm, the so-called sperm factor, is responsible for oocyte activation and that the fusion process i...