Features of functional activity of lipidome in Sus scrofa domesticus oocytes after intraovarian vitrification

Abstract

Abstract. The creation of a cryobank of reproductive cells and tissues opens up the possibility of intensifying the introduction of innovative cellular reproductive technologies into the practice of husbandry, biomedicine, and veterinary medicine. The aim of the study was to evaluate the effects of silicon dimethylglycerolate (SDMG) on the morphology of gametes and lipidome of porcine oocytes after intraovarian vitrification (IOV). Methods. Fragments (15 × 20 mm) of porcine ovaries were subjected to vitrification, which were exposed to cryoprotective agents (CPA1 and CPA2) for 25 minutes and 15 minutes. Composition: CPA1: 7.5 % ethylene glycol (EG), 7.5 % dimethyl sulfoxide (DMSO), 65 % PBS, with 2M bovine serum albumin (BSA) and CPA2 – 2.0% EG, 20 % DMSO, 60 % PBS, 1M BSA, 0.5 mol/l sucrose. The effectiveness of using SDMG at the studied concentrations on the cryopreservation of bio objects was assessed by: the morphology of gametes and indicators of the functional activity of the lipidome (morphology, localization and fluorescence intensity of lipid droplets visualized with Nile Red vital dye) in oocytes. Results. 0.2 % SDMG does not induce apoptotic processes in granulosa cells, reduces the level of naked cells. Addition of 2 % SDMG into the composition of cryoprotective media, the proportion of gametes with signs of morphological degeneration decreases (from 31 % to 13 %, P < 0.001). SDMG contributes to an increase in the level of gametes with positive indicators of the functioning of lipid droplets: the proportion of gametes with diffuse localization increases (from 58 % to 83 %, P < 0.001); the level of cells with low fluorescence intensity of the Nile red/lipid droplets complex (from 16 % to 29 %, P < 0.05) and the proportion of gametes with lipid granules (47 % vs. 68 %, P < 0.005) increased. Scientific novelty. For the first time, the effects of SDMG on the morphology of female gametes, apoptotic processes in the chromatin of granulosa cells and the functional activity of the lipidome of porcine oocytes under the influence of ultralow temperatures at IOV were identified. The media for IOV of oocyte-cumulus complexes were modernized with the addition of 0.2 % or 2 % SDMG.