Izvestiâ Akademii nauk. Rossijskaâ akademiâ nauk. Seriâ biologičeskaâ

In tumors, traditional angiogenesis is observed in addition to vascular channels that lack endothelial cell lining. It is assumed that the network of such channels compensates for the insufficiently development of the blood circulatory system in the tumor and prevents early necrosis inside the tumor. A strong statistical correlation established between the presence of vascular channels in the tumor and the low survival rate of patients confirms this hypothesis. In the light of these data, the search for a low-molecular inhibitor of vascular channels formation in a tumor becomes extremely relevant. This review discusses the functional and prognostic significance of vasculogenic mimicry. Particular attention is paid to the optimization of the in vitro vasculogenic mimicry model based on the analysis of 11 melanoma cell lines obtained from metastases of patients with disseminated melanoma. In addition, the development of an in vivo vasculogenic mimicry model is being discussed.

Cryptochromes compose the widespread class of blue-light sensory receptors that in plants regulate processes of development and circadian rhythm. These photoreceptors can also function as magnetoreceptors. Cryptochrome proteins bind flavin adenine dinucleotide (FAD) as a chromophore in the photolyase homology region (PHR) domain and contain the C-terminal extension (CCE) which is joined to PHR near the FAD-binding site. The cryptochrome activation is initiated by photochemical FAD conversions involving electron/proton transfer and the formation of redox forms. In plants, cryptochrome protein with photoreduced FAD undergoes conformational changes causing disengagement of the PHR domain and CCE that is accompanied by the formation of functionally active oligomers of cryptochrome molecules. Photooligomerization is considered as a key process necessary for cryptochrome signaling activity.

Cytogenetic analysis (routine, G-, C-, AgNOR-chromosome banding) allowed to obtain new data on chromosomal polymorphism in the population (n = 13) of Sicista sp. 1, representative of the Sicista subtilis group from the Saratov Region, right bank of Volga River. It was shown that in the studied polymorphic population of a species from the northern part of the species' range (Voskresensky district of the Saratov region) the diploid number of chromosomes varies from 2n = 22 to 2n = 24, and the number of autosome arms from NFa = 39 to NFa = 44, and the sample includes the following 6 karyotype variants: with 2n = 24, NFa = 44; 2n = 24, NFa = 43; 2n = 23, NFa = 40; 2n = 23, NFa = 41; 2n = 22, NFa = 39; 2n = 22, NFa = 40. Based on G‑banding method, the determined intrapopulation chromosomal polymorphism in Sicista sp. 1 was defined by two chromosomal rearrangements: tandem translocation involving two biarmed autosomes No 4 and 10 and a pericentric inversion of pair No 6. In the studied sample (n = 13), a stable advantage of heterozygotes was revealed for both structural chromosomal mutations and the chromosomal polymorphism is characterized as balanced or heterozygous. The potential role of the identified polymorphism in chromosomal evolution and adaptive strategy of the species is discussed.

Inherited endosymbiotic bacteria from the genera Rickettsia, Wolbachia and Spiroplasma cause the death of male offspring in ladybirds (Coleoptera, Coccinellidae). As a rule, bacteria are transmitted through the cytoplasm of the mother’s egg to offspring – vertically. In addition to vertical transfer, there is increasing evidence of horizontal transfer of symbionts between unrelated insect taxa. Insect parasites such as mites can be potential vectors of endosymbiotic bacteria. The parasitic mite Coccipolipus hippodamiae (McDaniel & Morrill, 1969) (Acarina: Podapolipidae) occurs in natural populations of Coccinellidae. In this work, the ability of C. hippodamiae to become infected with Wolbachia and Spiroplasma from hosts and to spread bacteria among coccinellid beetles was proven for the first time.

The relevance of the study is due to insufficient knowledge of the biological characteristics of hydrangeas. The aim of the research was to identify the anatomical and diagnostic features, as well as the chemical composition of the arborescent hydrangea (Hydrangea arborescens L.) from the collection of the South Ural Botanical Garden-Institute of the Ural Federal Research Center of the Russian Academy of Sciences. As a result of the research, it was found that the diagnostically significant features of the leaf of this type of hydrangea are the structure of the cells of the epidermis of the upper and lower sides of the leaf, the presence of an anomocytic stomatal apparatus on the lower side of the leaf, crystalline inclusions of calcium oxalate in the form of rafids on the upper and lower sides of the leaf, and simple hairs with coarse warty surface, multicellular base, as well as simple sinuous hairs on the underside of the leaf. Phytochemical analysis of leaves, stems and roots confirmed the presence of coumarins, ascorbic acid and tannins in them, and flavonoids in leaves. It has been established that the highest content of ascorbic acid (0.28 ± 0.014%) and tannins (7.13 ± 0.639%) is observed in the leaves of Hydrangea arborescens, coumarins in terms of umbelliferone in the roots (0.41 ± 0.007%), and the content of flavonoids in the leaves was 1.14 ± 0.048%.

The effect of light-emitting diode (LED) lamps with 5 different spectra on L. sativa plants (variety ‘Aficion’) grown in protected soil conditions was studied. Warm white light (WW) was used as a control (the ratio of blue, green and red portions in the spectrum was 14% : 48% : 38%). The maximum values of leaf size and fresh weight of the aerial parts were found in the RGB group (blue-green-red ratio 32% : 19% : 49%), highest values of dry weight and ash content – in the FS group (blue-green-red ratio 27% : 11% : 62%). Stomatal size and density on the abaxial leaf’s side was the highest in SB plants (blue-green-red ratio 33% : 41% : 38%). This was the most effective combination of parameters in terms of leaf architectonics. An increase in the portion of red light in the spectrum with a decrease in the portion of green light had a positive effect on the development of L. sativa plants, while an increase in the portion of green light in the spectrum positively affected-the stomatal apparatus formation.

A revision of the original description of the karyotype of the sable Martes zibellina was carried out, data on the mitotic metaphase chromosomes of the female and male of this species and a comparison of their sets with those of closely related species of the genus Martes are presented. We also provide a description of the synaptonemal complex (SC) in the early – middle prophase of meiosis in sable spermatocytes. Comparative analysis confirmed the stability and similarity of the main cytogenetic parameters of sables and martens (2n = 38, NFa = 64–68, X is the average submetacentric, and Y is the smallest meta,-submeta,- or acrocentric). A small polymorphism associated with the representation of one- or two-armed smallest elements of the diploid set of chromosomes was revealed. These features are of little use for the development of intraspecific taxonomy of sable, but can be used to reveal phylogenetic relationships at the species and generic levels, as well as to identify the consequences of natural hybridization of closely related species of the genus Martes.

The question of the size ratio of the body and the digestive tract (DT) in small phytophagous mammals is considered on the example of gerbils (Gerbillidae), a group of rodents that is exceptionally convenient for studying such relationships due to significant differences in body weight and morphological homogeneity of the DT. We analyzed the weight ratios of body size and DT, wet weight of contents and tissues of DT in 6 species of gerbils with a 10-fold body weight range (average 18 to 175 g) coexisting in the Negev desert – Psammomys obesus, Meriones crassus, Gerbillus pyramidum, Gerbillus allenbyi, Gerbillus dasyurus Gerbillus henleyi. In a number of studied species of small mammals weighing less than 0.5 kg, no linear relationship was found between body size and DT. The allometry of the considered indicators is mainly due to environmental and physiological factors.

The method of HRV analysis in rats was used to evaluate the relationship between the initial level of total HRV and regulatory changes in the work of the heart before and on days 1, 3, and 28 after the modeling of irreversible ischemia (II). According to the level of total HRV, rats were divided into two groups: with initially “low” and “high” levels of HRV, the LV (SD_RR = 5.0 ms) and HV (SD_RR = 8.2 ms) groups. LV and HV rats reacted differently to the cold test before and after II. Three days after II, LV rats had a better preservation of the autonomic regulation of the heart, and 28 days later, a smaller size of myocardial damage and mortality. In HV rats, the number of mast cells in the ischemic focus was higher, and in the zone unaffected by ischemia, the proportion of degranulated cells was higher than in LV rats.

Morphological and physiological parameters of leaves and tubers of 22 varieties of potato (Solanum tuberosum) were investigated. Discriminant analysis found that stomata size (12%), chlorophyll content (10%), number of tubers (29%), and average tuber weight (21%) determined the gradation of plants by yield. The specific surface density of leaves (38%), the content of chlorophyll (13%) and carotenoids (13%), and leaf area (12%) made the greatest contribution to discrimination in relation to ecological plasticity. It is concluded that the number of stomata per unit area of the leaf, the specific surface density of the leaf and the content of photosynthetic pigments are the key characteristics that contribute to both high yield and adaptive capacity of potatoes.

Using the method of scanning electron microscopy, a comparative study of the particle surface morphology and the elemental composition of the cuticle of Hermetia illucens pupa before and after the application of the culture liquid (CL) of the probiotic strain Lactobacillus acidophilus B 2707 was carried out. At the same time, under the influence of CL, destruction of relatively large particles of the powder of the chitin-protein complex of the cuticle (average particle diameter D 845.3 ± 109.1 μm) and the formation of small fragments (average D 63.4 ± 13.9 μm), including nanoparticles (average D 54 ± 18 nm). A biofilm of lactobacilli enriched with calcium, magnesium and phosphorus was obtained on a sorbent consisting of microparticles of the cuticle of insect pupae and including nanoparticles, which provided the probiotic preparation with high biological efficiency.