Kinase CDK2 in Mammalian Meiotic Prophase I: Screening for Hetero- and Homomorphic Sex Chromosomes

Cyclin-dependent kinases (CDKs) are crucial regulators of the eukaryotic cell cycle. The critical role of CDK2 in the progression of meiosis was demonstrated in a single mammalian species, the mouse. We used immunocytochemistry to study the localization of CDK2 during meiosis in seven rodent species that possess hetero- and homomorphic male sex chromosomes. To compare the distribution of CDK2 in XY and XX male sex chromosomes, we performed multi-round immunostaining of a number of marker proteins in meiotic chromosomes of the rat and subterranean mole voles. Antibodies to the following proteins were used: RAD51, a member of the double-stranded DNA break repair machinery; MLH1, a component of the DNA mismatch repair system; and SUN1, which is involved in the connection between the meiotic telomeres and nuclear envelope, alongside the synaptic protein SYCP3 and kinetochore marker CREST. Using an enhanced protocol, we were able to assess the distribution of as many as four separate proteins in the same meiotic cell. We showed that during prophase I, CDK2 localizes to telomeric and interstitial regions of autosomes in all species investigated (rat, vole, hamster, subterranean mole voles, and mole rats). In sex bivalents following synaptic specificity, the CDK2 signals were distributed in three different modes. In the XY bivalent in the rat and mole rat, we detected numerous CDK2 signals in asynaptic regions and a single CDK2 focus on synaptic segments, similar to the mouse sex chromosomes. In the mole voles, which have unique XX sex chromosomes in males, CDK2 signals were nevertheless distributed similarly to the rat XY sex chromosomes. In the vole, sex chromosomes did not synapse, but demonstrated CDK2 signals of varying intensity, similar to the rat X and Y chromosomes. In female mole voles, the XX bivalent had CDK2 pattern similar to autosomes of all species. In the hamster, CDK2 signals were revealed in telomeric regions in the short synaptic segment of the sex bivalent. We found that CDK2 signals colocalize with SUN1 and MLH1 signals in meiotic chromosomes in rats and mole voles, similar to the mouse. The difference in CDK2 manifestation at the prophase I sex chromosomes can be considered an example of the rapid chromosome evolution in mammals.     

Genome-Wide Characterization of Jasmonates Signaling Components Reveals the Essential Role of ZmCOI1a-ZmJAZ15 Action Module in Regulating Maize Immunity to Gibberella Stalk Rot

Gibberella stalk rot (GSR) by Fusarium graminearum causes significant losses of maize production worldwide. Jasmonates (JAs) have been broadly known in regulating defense against pathogens through the homeostasis of active JAs and COI-JAZ-MYC function module. However, the functions of different molecular species of JAs and COI-JAZ-MYC module in maize interactions with Fusarium graminearum and regulation of diverse metabolites remain unknown. In this study, we found that exogenous application of MeJA strongly enhanced resistance to GSR. RNA-seq analysis showed that MeJA activated multiple genes in JA pathways, which prompted us to perform a genome-wide screening of key JA signaling components in maize. Yeast Two-Hybrid, Split-Luciferase, and Pull-down assays revealed that the JA functional and structural mimic coronatine (COR) functions as an essential ligand to trigger the interaction between ZmCOIa and ZmJAZ15. By deploying CRISPR-cas9 knockout and Mutator insertional mutants, we demonstrated that coi1a mutant is more resistant, whereas jaz15 mutant is more susceptible to GSR. Moreover, JA-deficient opr7-5opr8-2 mutant displayed enhanced resistance to GSR compared to wild type. Together, these results provide strong evidence that ZmJAZ15 plays a pivotal role, whereas ZmCOIa and endogenous JA itself might function as susceptibility factors, in maize immunity to GSR.     

Effectiveness and prospects of using different solar water heating systems under the climatic conditions of the Russian Federation

The results obtained from simulating the operation of three types of solar hot water supply installations in the territory of the Russian Federation is presented: a simplest hot-water installation with accumulation of heated water directly in a solar collector and solar water-heating installations equipped with a separate storage tank and flat-plate or tubular evacuated solar collectors.     

Cardio-cerebral hemodynamics and the prostanoid system in patients with the initial stages of essential hypertension

The comparative study of the main characteristics of immune status in patients with urogenital chlamydiosis, furunculosis, urogenital herpes (38 patients) and in the members of the control group (21 subjects) was made. The analysis of the results obtained in this study revealed the numerical values of immunological characteristics, capable of being used as markers indicating transition into the chronic form. Thus, it showed a decrease in the population of cells with phenotype CD72+ in chlamydiosis; a fourfold increase in the population of cells with phenotype CD16+ in furunculosis; an increase in the population of cells with phenotype CD8+, a decrease in the immunoregulatory index and the population of cells with phenotype CD72+ in herpes. The data thus obtained may be used in prescribing immunocorrective therapy.     

Assessment of porosity and structure of powder materials based on mechanically activated Ni-Fe-NaCl charges

Electron-probe microanalysis methods were used to study the formation of structure and the distribution of various components in high-porosity powder materials during heat treatment of compacts based on Ni-Fe-NaCl charges mechanically activated in fluid media. We confirmed the hypothesis that agglomerates are formed during mechanical activation of Ni-and Fe-based composite-particle charges in fluid media. A causal relationship was established between formation of structure in compacts and structure of the high-porosity powder material after heat treatment. A technique was proposed for determining the local porosity of the sintered high-porosity powder material. The structure of the high-porosity powder material was found to consist of large pores surrounded by powder material containing pores of smaller diameter.     

Spheroid Formation and Peritoneal Metastasis in Ovarian Cancer: The Role of Stromal and Immune Components

Ovarian cancer (OC) is one of the most common gynecological cancers, with the worst prognosis and the highest mortality rate. Peritoneal dissemination (or carcinomatosis) accompanied by ascites formation is the most unfavorable factor in the progression and recurrence of OC. Tumor cells in ascites are present as either separate cells or, more often, as cell aggregates, i.e., spheroids which promote implantation on the surface of nearby organs and, at later stages, metastases to distant organs. Malignant ascites comprises a unique tumor microenvironment; this fact may be of relevance in the search for new prognostic and predictive factors that would make it possible to personalize the treatment of patients with OC. However, the precise mechanisms of spheroid formation and carcinomatosis are still under investigation. Here, we summarize data on ascites composition as well as the activity of fibroblasts and macrophages, the key stromal and immune components, in OC ascites. We describe current knowledge about the role of fibroblasts and macrophages in tumor spheroid formation, and discuss the specific functions of fibroblasts, macrophages and T cells in tumor peritoneal dissemination and implantation.     

Effect of mechanical activation of Ni-Fe-NaCl powder charges in liquid media on the structure and properties of high-porosity materials

It has been established that the time of activation in liquid media (LMA) and the iron content of the charge are of decisive importance in determining the porosity of sintered materials. The authors determined the critical time of treatment for a charge inside a mill (1.5 ksec), this length of treatment ensuring that the transition from LMA to mechanical activation takes place. They also determined the optimum values for the process parameters, making it possible to obtain sintered high-porosity materials (HPM) with the porosity P = 64%.