ANALYSIS OF PARAMETERS OF MORPHOFUNCTIONAL STATE OF PIG OOCYTE LIPIDOME IN CASE OF IN VITRO CULTIVATION

Abstract

Identification of effective markers of oocyte maturation based on morphological and functional characteristics of intracytoplasmic lipid droplets will allow to increaseinformative value of the criteria for assessing the quality of donor gametes for improvement of the efficiency of using cellular reproductive technologies in animal husbandry, biomedicine, and veterinary medicine. The aim of the study is to analyze the parameters of morphofunctional state of the lipidome (the morphology of lipid droplets and the intensity of fluorescence of the Nile red/lipid droplets complex - Nile red IF) in Susscrofadomesticus oocytes before and after in vitro cultivation. Oocytes were matured using Sage Media Cleavage (CooperSurgical, USA) with 5% Serum Protein Substitute serum (CooperSurgical, USA), 10 IU human chorionic gonadotropin (Sigma, USA). As a result of ranking the population of donor oocytes according to morphology of lipid droplets (granules and clusters) and Nile red IF (low, medium, high), it was found that, the proportion of oocytes with an average Nile red IF and lipid droplets (LD) in the form of granules was 63% before cultivation, which was significantly higher than the proportion of gametes with an average IF of Nile red and LD of a mixed form of 41% (P<0.05). After cultivation, the level of oocytes with medium Nile red IF and LD in the form of granules was 45%, which exceeded the level of gametes with the same Nile red IF and mixed LD of 23% (P<0.05). The proportion of in vitro matured oocytes with high Nile red IF and mixed LD morphology (granules and clusters) was 33%, 14% were characterized by the above parameters before cultivation (P<0.05). Comparative morphological analysis of the relation between the parameters of morphofunctional activity (morphology and IF Nile red) of lipidome in Susscrofadomesticus oocytes was carried out for the first time. Features of functional activity of lipidome before and after cultivation were revealed. The usage of a comprehensive analysis of parameters of functional activity of lipidomeforassessment of the quality of the oocyte is substantiated. Pig oocytes which morphology of lipid droplets is represented by a granular form are promising for cultivation, while Nile red IF is assessed as low. With regard to the analysis of the obtained results, it is recommended to use the proposed comprehensive assessment of lipidome based on morphology and Nile red IF to assess the initial population of donor oocytes in cellular reproductive technologies.