Department of Basic and Preclinical Sciences, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, 87-100 Torun, Poland.
Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-719 Olsztyn, Poland.
Int J Mol Sci. 2023 Apr 6;24(7):6837. doi: 10.3390/ijms24076837.
It is a well-known fact that the reproductive organs in women, especially oocytes, are exposed to numerous regulatory pathways and environmental stimuli. The maternal age is one cornerstone that influences the process of oocyte fertilization. More precisely, the longer a given oocyte is in the waiting-line to be ovulated from menarche to menopause, the longer the duration from oogenesis to fertilization, and therefore, the lower the chances of success to form a viable embryo. The age of menarche in girls ranges from 10 to 16 years, and the age of menopause in women ranges from approximately 45 to 55 years. Researchers are paying attention to the regulatory pathways that are impacting the oocyte at the very beginning during oogenesis in fetal life to discover genes and proteins that could be crucial for the oocyte's lifespan. Due to the general trend in industrialized countries in the last three decades, women are giving birth to their first child in their thirties. Therefore, maternal age has become an important factor impacting oocytes developmental competence, since the higher a woman's age, the higher the chances of miscarriage due to several causes, such as aneuploidy. Meiotic failures during oogenesis, such as, for instance, chromosome segregation failures or chromosomal non-disjunction, are influencing the latter-mentioned aging-related phenomenon too. These errors early in life of women can lead to sub- or infertility. It cannot be neglected that oogenesis is a precisely orchestrated process, during which the oogonia and primary oocytes are formed, and RNA synthesis takes place. These RNAs are crucial for oocyte growth and maturation. In this review, we intend to describe the relevance of regulatory pathways during the oogenesis in women. Furthermore, we focus on molecular pathways of oocyte developmental competence with regard to maternal effects during embryogenesis. On the background of transcriptional mechanisms that enable the transition from a silenced oocyte to a transcriptionally active embryo, we will briefly discuss the potential of induced pluripotent stem cells.
众所周知，女性的生殖器官，尤其是卵子，会受到众多调控途径和环境刺激的影响。母体年龄是影响卵子受精过程的一个重要因素。更确切地说，从初潮到绝经，卵子在等待排卵的过程中停留的时间越长，从卵子发生到受精的时间就越长，因此成功形成可育胚胎的机会就越低。女孩的初潮年龄在 10 岁至 16 岁之间，而女性的绝经年龄在大约 45 岁至 55 岁之间。研究人员正在关注影响卵子发生过程中卵子的调控途径，以发现可能对卵子寿命至关重要的基因和蛋白质。由于过去三十年来工业化国家的普遍趋势，女性在三十多岁时才生育第一个孩子。因此，母体年龄已成为影响卵子发育能力的一个重要因素，因为女性年龄越高，由于多种原因（如非整倍体）导致流产的几率就越高。卵子发生过程中的减数分裂失败，例如染色体分离失败或染色体不分离，也会影响上述与年龄相关的现象。女性年轻时的这些错误可能导致亚不孕或不孕。不能忽视的是，卵子发生是一个精确协调的过程，在此过程中形成卵原细胞和初级卵子，并进行 RNA 合成。这些 RNA 对卵子的生长和成熟至关重要。在这篇综述中，我们旨在描述女性卵子发生过程中调控途径的相关性。此外，我们还关注了与胚胎发生过程中的母体效应有关的卵子发育能力的分子途径。在使沉默卵子向转录活性胚胎过渡的转录机制的背景下，我们将简要讨论诱导多能干细胞的潜力。
