background & objectives : different energy substrates and nutrients can greatly influence oocyte nuclear and cytoplasmic maturation. effect of glucose on in-vitro oocyte maturation and subsequent early embryonic development is controversial. the objective of the present study was to verify the effect of various concentrations of glucose on cumulus-oocyte complexes maturation, fertilization and ...

Bovine seminal ribonuclease (BS-RNase) contains the MxM (noncovalent dimer) and M=M (free monomer) in constant ratio. The aim of this work was to evaluate the effect of BS-RNase, its monomer and dimer forms, and also various mutants of this enzyme on meiotic completion in cattle oocytes. It was found that BS-RNase has irreversible effects on the meiotic maturation of bovine oocytes in vitro, pa...

the objective of this study was to compare the effectiveness of various combination activators of bovine oocyte following intracytoplasmic sperm injection (icsi) in terms of cleavage and embryo development. bovine icsi oocytes were treated with a variation of treatments of combined or single activators as follows; 30 v for 15 x 2 μsec of electrical pulse +10 μg/ml cycloheximide (chx),7% ethanol...

Maturation of immature bovine oocytes requires cytoplasmic polyadenylation and synthesis of a number of proteins involved in meiotic progression and metaphase-II arrest. Aurora serine-threonine kinases--localized in centrosomes, chromosomes, and midbody--regulate chromosome segregation and cytokinesis in somatic cells. In frog and mouse oocytes, Aurora A regulates polyadenylation-dependent tran...

Developmental competence of in vitro matured (IVM) oocytes needs to be improved and this can potentially be achieved by adding recombinant bone morphogenetic protein 15 (BMP15) or growth differentiation factor (GDF9) to IVM. The aim of this study was to determine the effect of a purified pro-mature complex form of recombinant human BMP15 versus the commercially available bioactive forms of BMP1...

Bovine in vitro embryo production (IVP) has been around for about three decades. Over the years, it has gained a reputation as one of the most applicable of the high-tech bovine assisted reproduction techniques. It is well known that its ups and downs are basically driven by economic imperatives depending on the agricultural system in which it is used. In parallel, there has always been a stron...

Using an interspecies microinsemination assay with bovine oocytes, it was examined whether centrosomes of Antarctic minke whale spermatozoa function as the microtubule-organizing centre (MTOC). Bull and rat spermatozoa were used as positive and negative controls, respectively. Vitrified-warmed bovine mature oocytes were subjected to immunostaining against alpha-tubulin 4-6 h after intracytoplas...

AIM Thecurrent study aims at investigating the polyadenylated (poly[A]) tail length of morphologically high and low competent oocytes at different developmental stages. Furthermore, effect of ultra-rapid vitrification on the poly(A) tail length was studied. MATERIALS AND METHODS Fresh bovine cumulus oocyte complexes from abattoir originated ovaries were graded based on morphological character...

BACKGROUND Many studies reported that follicle size has an essential role in developmental potential of oocytes. Also, the brilliant cresyl blue (BCB) test is one of the most important criteria in selection of more competent oocytes. OBJECTIVE Selection of developmentally competent bovine oocytes. MATERIALS AND METHODS A total of 1730 bovine cumulus oocyte complexes (COCs) were recovered fr...

In this work we analyze the effects of vitrification on the ultrastructure and developmental ability of bovine oocytes matured in the presence of 9-cis-retinoic acid (RA). Bovine cumulus oocyte complexes (COCs) were matured in a basic medium containing 10% fetal calf serum (FCS), 9-cis-RA or polyvinyl alcohol (PVA). Mature oocytes were vitrified using the Open Pulled Straw method with minor mod...