| dc.description.abstract | Nowsaday, in many laboratories, people often use follicles that have the sizes of 2-6 mm in diameter to isolate oocytes for culture in vitro maturation (IVM) by aspiration method. If the follicle have the range from 2-<3 mm, 3-<4 and 4-<6 mm in diameter, the oocytes in them have the sizes of 115.3 ±3.0 μm, 119.8±2.7 and 122.1 ±2.2 μm in diameter, respectively. However, only pig oocytes in antral follicles of 4-6 mm with 122.1 ±2.2 μm diameter, acquire the meiotic competence. So, the purpose of this research is to estimate the difference meiotic competence of pig oocytes in different sizes :2-3 mm, 3-4 mm and 4-6mm in diameter of pig follicle.
This study was conducted with two objectives : examine the cumulus expansion as well as nuclear morphologies of oocytes in three kinds after IVM.
Porcine ovaries were collected at the local slaughterhouse and then, we used the surgical blades to remove the cortical slices from ovaries, extract follicles from these slices and release the oocyte from these extracted follicles. The oocytes were divided into three groups depending on the sizes of follicles : 2-3 mm (type A), 3-4 mm (type B), 4-6 mm (type C) in diameter. After that, oocytes were released in the HEPES medium and transfer into another HEPES for washing two times via mouth pipette, finally we washed oocytes three times with TCM-199. A 48-well plate was prepared with TCM-199, sodium pyruvate, hcG, 10% follicle fluid, oocytes were cultured in this plate for in vitro growth during 48 hours in 5% CO2 at 37.5⁰C. Then, after IVM, oocytes were denuded and fixed in aceto alcohol (1/3) and stain in 1% orcein. Data was collected either by staining with 1% aceto orcein to determine nuclear status. Results indicated that the oocytes from follicles of 4-6 mm in diameter have the highest percentages of meiotic competence because they showed good performances in cumulus expansion as well as reaching at the metaphase II (82,9% and 63,22%, respectively). From these results, we suggest using the oocytes from the follicles of 4-6 mm in diameter for in vitro growth in the laboratory.
Keywords: In vitro maturation, sizes of follicles, porcine oocytes, medium culture, nuclear status. | en_US |
