Developmental potential of bovine oocytes matured in vitro or in vivo

Increasing the cAMP concentration during in vitro maturation of pig oocytes improves cumulus maturation and subsequent fertilization in vitro

“…Polyspermy, or the penetration of more than one sperm cell into the oocyte, represents a major problem during porcine IVF [2]. The polyspermy rate with in vivo-matured oocytes is higher in pigs (28%, [3]) than that in other species (11% in cattle [4]). With porcine oocytes matured in vitro, polyspermy rates reach levels of 65% [3].…”

Damaging effect of cumulus denudation on rabbit oocytes

“…After 1-heptanol treatment, three types of lucifer yellow diffusion were observed: [1] into all the cumulus cells (Fig. 1A), [2] into only the corona cells (Fig.…”

“…Cumulus-free oocytes were [1] fixed in 4% paraformaldehyde in PBS for 1.5 hours, [2] incubated with 0.3% H 2 O 2 in methanol for 10 minutes, [3] treated with 0.1% Triton X-100 for 2 hours, [4] incubated with 50-mL terminal deoxynucleotidyl transferase enzyme reaction mixture for 1 hour, [5] incubated with 50-mL streptavidin-horseradish peroxidase for 30 minutes, [6] exposed to the 3,3 0 -diaminobenzidine tetrahydrochloride substrate solution for 10 minutes, and [7] stained with 10 mg/mL Hoechst 33342 for 10 minutes; TUNEL labeling was examined with use of a phase contrast and Hoechst staining was observed with use of a fluorescence microscope.…”

“…Zona-free oocytes were [1] fixed with 3.7% paraformaldehyde for 30 minutes; [2] permeabilized for 5 minutes in 0.1% Triton X-100 in PBS-Polyvinyl alcohol (PVA); [3] incubated with a rabbit anti-Bcl-2 polyclonal antibody (1:100; NovoGene Lifesciences Pvt Ltd., Mumbai, India) for 1 hour; [4] incubated with 1:200 dilution of a secondary goat anti-rabbit IgG conjugated with fluorescein isothiocyanate conjugate (NovoGene); and [5] observed with a Leica laser scanning confocal microscope (Leica Microsystems GmbH, Wetzlar, Germany) (35).…”

“…Preimplantation development of the in vitro matured oocytes after IVF is less successful than that of oocytes matured in vivo (1)(2)(3). An efficient in vitro maturation system for cumulus-denuded oocytes is needed urgently for procedures involving cumulus removal before in vitro maturation.…”