Том 47, № 6 (2016)

The role of cGMP (cyclic guanosine monophosphate) in the suppression of apoptosis in preantral and preovulatory follicles has been established. But the underlying mechanisms have not yet been established. The present study has been focused on revealing the mechanisms involved in the cGMP mediated suppression of apoptosis and in survival of ovarian follicle. cGMP reduces calcium burden of the cell by mediating Ca²⁺ channels, BK (Big Potassium) channels, phosphatidylinositol 3-kinase (PI3K)/Akt pathway thus, prevents the mitochondrial membrane pore formation and apoptosis. cGMP induces the expression of Trx (thioredoxin) protein and prevents the TNF-α (Tumour Necrosis factor) induced apoptosis. cGMP also induces the expression of cytoskeleton proteins which are involved in heterogeneous distribution of mitochondria and there by reduces the Ca²⁺ burden and apoptosis. Histone 3 lysine 4 methyltransferase (MLL2) is an epigenetic factor inhibits the transcription of genes involved apoptosis which acts as co-activator of Estrogen receptor-α. In conclusion the present review predicts some mechanisms underlying the cGMP mediated suppression of apoptosis in ovarian follicles.

The mammalian germinal vesicle–stage (GV) oocytes are divided into two major types, NSN (non-surrounded nucleolus) and SN (surrounded nucleolus), and at least one intermediate type, pSN (partly surrounded nucleolus), based on large-scale chromatin configuration. In mice, the SN oocytes are considered to be the most meiotically competent, which explains active study of their phenotypic characteristics necessary for improvement of human reproductive technologies. One of such characteristics is the position of the GV (nucleus) relative to the center of the oocyte. However, the current data on this issue are contradictory and even completely absent for pSN oocytes. In this work, we have studied the GV position in 187 mouse GV oocytes belonging to NSN, SN, and pSN types using different approaches known from the literature. Our results suggest that (1) the most abundant in all examined types of oocytes are central GVs (43–66%) and the least abundant are peripheral GVs (12–39%); the pSN oocytes are closer to SN oocytes rather than to NSN oocytes according to the GV position; (3) the position of the nucleus in mouse GV oocytes is an ambiguous marker of large-scale chromatin configuration and, correspondingly, maturation competence of the oocyte; (4) the diversity of the GV position in NSN, SN, and pSN oocytes most likely reflects the ability of GVs to migrate; and (5) assessment of the GV position according to three variants (central, peripheral, and intermediate) is more informative as compared with two variants (central and peripheral).

The lengths of meristematic (l_m) and fully-elongated cells (l_e) were measured in the roots of 118 monocot and dicot species of herbaceous plants from 20 angiosperm families. The results were analyzed using the data on haploid DNA content (C_val) for the same species from the website (http://data.kew.org/cvalues). The distribution range of l_m, l_e, and C_val was wider in monocot plants compared to dicots. Values of l_m and l_e in monocot and l_m in dicot species correlated positively with C_val. Dependence of l_m and l_e on C_val was similar in diploid and polyploid species, both monocots and dicots. The average length of root cells differed less than the root length.

Information about embryonic development of coronary endothelium is the main clue for the creation of new methods in tissue engineering for treatment of ischemic heart diseases. The purpose of the research was to describe human coronary vessels development on early stages of the prenatal ontogenesis. The first step in human coronary vessels development is the formation of endothelium de novo by transformation of some epicardial and, possibly, endocardial cells. The next step is the ingrowth of sinus venosus endothelium in subepicardium over ventricles and atria, which gives rise to the coronary vessels. Only after 7 days does the primitive coronary plexus of the heart communicate with aorta (third step). During this period, some subepicardial vessels invade myocardium and some intramyocardial vessels contact with the heart cavity. Such intercommunications could help in regulation of blood circulation in primitive coronary plexus before establishment of effective contacts between arterial and venous vessels—excess of blood could be discharged directly into the heart cavity. Additional population of CD34+ cells were revealed inside condensed mesenchyme of the conotruncus; it participates in the formation of vasa vasorum in the aorta. Epicardium and sinus venosus generate endothelium of coronary vessels by neovasculo- and angiogenesis, respectively. During a week after ingrowth of vessels from SV and before their ingrowth to the aorta, ventriculo-coronary communications could be found in the heart.

The features of the formation of microshoots in in vitro culture of Silene cretacea—endangered species with narrow ecological amplitude, which is a promising source of medicinal raw materials—were studied. It was demonstrated that, at the micropropagation step, basic Woody Plant Medium containing vitamins according to Murashige and Skoog and supplemented with 0.2 mg/L 6-benzylaminopurine, 1.0 mg/L kinetin, 1.0 mg/L gibberellic acid, and 0.5 mg/L indole-3-acetic acid is the most effective. The combination and concentration of these growth regulators, selected using mathematical combinatorial analysis, activated axillary buds and provided a high multiplication factor (9.3 ± 1.3 microshoots per explant). Morpho-histological analysis revealed the main stages of the formation of microshoots and proved the absence of callus formation during the whole time of the cultivation of explants. The features of the dynamics of the culture during the year of continuous cultivation are presented.