Formation of ovarian reserve

• Main Author: V. G. Zenkina
• Format: Article
• Language: English
• Published: Siberian State Medical University (Tomsk) 2018-09-01
• Series: Bûlleten' Sibirskoj Mediciny
• Subjects: follicular reserve; ovary; molecular genetic mechanisms
• Online Access: https://bulletin.tomsk.ru/jour/article/view/1299

The review of the literature is devoted to modern data on the formation of the ovarian reserve of the female sexual organ. The relationship between the size of the ovarian reserve and length of reproductive capacity emphasizes the importance of understanding the regulatory factors and processes that determine its creation. We described ovarian reserve markers and regulators such as oocyte phosphotidylinositol-3-kinase, a stem-cell factor (kit ligand) that promote the survival of follicles during neonatal development, synaptonemic complex (SCP3), which is the marker of the first division of meiosis, as well as genes DMC1 and PTEN, involved in meiotic transformations and recruitment of primordial follicles. Changes in the expression of some genes and factors in the human fetal ovaries during primary follicular assembly now give an idea of the ways controlling early folliculogenesis. Aberrant production of these factors can cause dysfunction, the development of ovarian disorders and a defective follicular reserve. In particular, the degree of change in the number of germ cells at each of the stages leading to the creation of an ovarian reserve should be noted. This change can affect the final size of the follicular stock, and, consequently, the reproductive longevity of a person and health in the postproductive period. In particular, the number of primary follicles during puberty is positively correlated with the number of growing follicles and their response to gonadotropin treatment. The size of the ovarian reserve depends on the genes involved in proliferation and differentiation of germ cells, sexual differentiation, meiosis, germ cell degeneration, the formation of primary follicles, and the potential mechanism for self-renewal of embryonic stem cells. For example, a possible molecular mechanism has been established leading to a meiotic process in oocytes involving the above genes and factors, as well as apoptotic and antiapoptical signals: Bax, Bcl-2, p53, CDK1, Lsd1, Notch, Stra8, Dazl, Dmc1, Rec8, XIAP , PUMA. Therefore, understanding all the subtleties and molecular mechanisms at each stage of laying down and developing the ovaries, sex cells and their environment, and the death of gametes, can help to search for possible regulators and prevent pathological depletion of the follicular stock.