EN
Several morphological, molecular and cellular changes lead to the differentiation of primordial germ cells (PGC) into gametes, eggs and spermatozoa. This process is followed by the migration of these cells to gonads and several cell division cycles (mitotic and meiotic) as well as cell differentiations where these cells are changed into fully mature gametes. The process of gametes maturation is composed of several stages of specific biochemical changes that include changes in the nucleus as well as the changes in oocyte’s cytoplasm. The main factor which determines the formation of the developmental competence of oocytes is the long stage of mRNA and proteins storage (cytoplasmic maturation) that plays the main role in the blastocyst formation process. In this article selected issues associated with the regulation of each of the stages of oocytes differentiation as well as their influence of selected factors such as follicular size or formation of oocyte’s transcriptome have been presented. Moreover, a new-noninvasive system of oocytes/embryos quality assessment by using microfluidic techniques was presented.