132 Influence of oocyte retrieval methods and maturation media on in vitro development of polar body extrusion in pig oocytes
K. M. Honneysett A B , M. L. Mphaphathi B , A. M. Maqhashu A and E. C. Webb AA Department of Animal and Wildlife Sciences, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa;
B Animal Production, Agricultural Research Council, Irene, South Africa
Reproduction, Fertility and Development 33(2) 174-174 https://doi.org/10.1071/RDv33n2Ab132
Published: 8 January 2021
Abstract
Oocyte recovery is a reproductive technology that can be done by using two techniques, aspiration and slicing. In vitro maturation (IVM) is an additional reproductive technology used to advance an oocyte to a maturation stage; thereafter, it may be used during IVF. The objectives of the present study were (1) to compare two different oocyte retrieval methods (aspiration and slicing) from pig ovaries on oocyte quality and quantity, and (2) to compare three different IVM media [NCSU 37, TCM-199, and modified porcine follicular fluid (mpFF = porcine follicular fluid + FSH + LH] on oocytes’ polar body extrusion. During aspiration, an 18 G needle was attached to a 10-mL syringe and all visible follicles were aspirated. During slicing, a surgical blade was used to slice the ovaries held in mDPBS. Follicular fluid collected from both methods was assessed for the presence of oocytes with the aid of a microscope. The collected oocytes were then categorized as Grade A, B, or C: Grade A = oocytes with compacted, multilayered cumulus cells and a homogeneous ooplasm; Grade B = oocytes with a compact cumulus cell layer with homogeneous ooplasm; Grade C = oocytes with a less compact cumulus cell layer with irregular ooplasm containing dark granules. The IVM media were placed in a four-well multidish; thereafter Grades A and B oocytes were allocated per treatment groups and matured for 44 h. The treatment means were compared using the Fisher’s protected t-test least significant difference. The results showed significant differences between the grades of oocytes (P < 0.05) with Grade A and B oocytes accounting for 50.8% of total oocytes (193.8) for aspiration and 58.7% of total oocytes (488.6) for slicing. The oocytes polar body extrusion was recorded as 25.3, 84.2, and 73.8% for NCSU 37 (P < 0.05) and TCM-199 and mpFF respectively (P > 0.05). In conclusion, the slicing method proved to be better than aspiration with regards to the retrieval of Grades A and B oocytes as well as the total number of oocytes retrieved. The TCM-199 and mpFF media had a higher percentage of oocytes with polar body extrusion than NCSU 37.
