Cytoplasmic and nuclear maturation of oocytes in mammals – living in the shadow of cells developmental capability

Abstract

The pig is a polyestrous animal in which the ovarian cycle lasts about 21 days and results in ovulation of 10-25 oocytes. Ovum reaches 120-150 μm in diameter, with the surrounding corona radiata providing communication with the environment. The zona pellucida is composed of glycoproteins: ZP1, ZP2, ZP3. In the course of oogenesis, RNA and protein accumulation for embryonic development occurs. Maternal mRNA is the template for protein production. Nuclear, cytoplasmic and genomic maturity condition the ability of the ovum to undergo fertilization. There are several differences in protein expression profiles observed between in vitro and in vivo conditions. Oogenesis is the process of differentiating female primary sex cells into gametes. During development gonocytes migrate from the yolk sac into the primary gonads with TGF-1, fibronectin, and laminin regulating this process. Cell cycle is blocked in dictyotene. Primary oocyte maturation is resumed before each ovulation and lasts until the next block in metaphase II. At the moment of penetration of the sperm into the ovum, the metaphase block is broken. The oocytes, surrounded by a single layer of granular cells, form the ovarian follicle. The exchange of signals between the oocyte and the cumulus cells done by gap-junctions, as well as various endo and paracrine signals. The contact between the corona radiata cells provides substances necessary for growth, through the same gap junctions. Studies on follicular cells can be used to amplify the knowledge of gene expression in these cells, in order to open way for potential clinical applications. Running title: ovarian cysts formation

Genes Involved in the Processes of Cell Proliferation, Migration, Adhesion, and Tissue Development as New Potential Markers of Porcine Granulosa Cellular ProcessesIn Vitro: A Microarray Approach

“…Interactions of mammalian gametes with the surrounding somatic cells are important for the success of folliculogenesis and fertilization, which are closely regulated by complex signaling events mediated through various genes, proteins, and enzymes (Matzuk et al, 2002;Rybska et al, 2018a). These processes cause the differentiation of the ovarian follicle from primordial, through primary and secondary, into the mature Graafian follicle (Uyar et al, 2013;Rybska et al, 2018b). It was proven that proper follicular physiology is required for complete oocyte maturation.…”

Expression of Selected Connexin and Aquaporin Genes and Real-Time Proliferation of Porcine Endometrial Luminal Epithelial Cells in Primary Culture Model

“…e cells were cultured at 38°C in a humidified atmosphere of 5% CO 2 . e culture medium was changed every 3 days [13,14].…”

“…FITC was excited at 488 nm with an argon laser, with emissions being imaged through a 505-530 nm filter. All confocal microscopic images were analyzed using Imaris 7.2 software (BitPlane, Zurich, Switzerland) [13,14]. In order to validate the specificity of antibodies for all samples, we used control experiment where only secondary antibody was used, and to analyze the changes in the expression of proteins, we used 10 images for each sample.…”

Human Ovarian Granulosa Cells Isolated during an IVF Procedure Exhibit Differential Expression of Genes Regulating Cell Division and Mitotic Spindle Formation

“…From an oocyte viewpoint, the most important function of GCs is their participation in bidirectional communication, which allows for the exchange of signals and cellular metabolites between these two cell types [1]. GCs are an important factor in the comprehension of the folliculogenesis process [2,3]. However, understanding their transcriptome may be an important step in expanding knowledge about their possible application to medicine of the 21st century.…”