Assessment of the destructive processes of chromatin of granulosa cells and functional status of oocyte in bovine ovarian follicles

Abstract

Abstract. Currently, there is the possibility of more detailed studies to the study of oocytes and somatic cells (granulosa cells). The possibility to develop successful models of maturation of female gametes defines the possibility to improve existing methods for the selection of donor eggs and the search for new donor eggs. Oocyte maturation in vivo occurs with the participation of structural follicle elements and follicular fluid [3, 4, 6]. Granulosa cells are widely used in bovine oocyte maturation systems and used in cloning and transgenesis technologies [8, 13]. Purpose of this study: to perform destructive changes granulosa cells in ovarian follicles of bovines (Ø 3–5 mm),which contain growing(ВСВ–) or completed the growth phase of oocytes (ВСВ+). Methods: Functional testing of oocytes wascarried out using the vital dye BCB (brillant cresyl blue – diamond crystal blue) [10]. Viability indices in granulosa cells isolated from follicles that contain oocyte s that grow or complete the growth phase were determined by flow cytometry. The result. It was found, that cellsof granulosa from cow follicles are characterized by different indicators of apoptosis levels depending on the status of oocytes (completed growth and growing) isolated from these follicles. The proportion of apoptotic granulosa cells in bovine follicles of containing oocytes that completed the growth phase, exceeded that in follicles containing growing oocytes by 11 % (29 % vs. 18 %, c:dP < 0.05). The scientific novelty: The data obtained using flow cytometry, allow us to evaluate the level of apoptosis in granulosa cells of bovine ovarian follicle as indicator of functional status of developing oocytes (growing or completed growth phases). This indicator can be used in prognosis of competencies for maturation of bovine oocytes.