Nº 5 (2025)

Introducing of molecular genetic (MG) methods into the study of the causative agent of plague, the microbe Yersinia pestis, has led to two important discoveries in the problem of reconstructing the phylogenetic history of this apocalyptic pathogen. Its direct ancestor was identified as the causative agent of intestinal infection, – Far Eastern scarlet-like fever (FESLF, Y. pseudotuberculosis 0:1b), and the time of divergence from the direct ancestor was established at – no earlier than 30 thousand years ago, in the Late Pleistocene or Holocene. However, molecular methodology does not allow us to create a sufficiently substantiated scenario of the origin and global expansion of the plague microbe. The MG conclusions are not consistent with the facts provided by other natural sciences, primarily ecology and biogeography. At the same time, these discoveries made it possible to create a consistent ecological (ECO) scenario and propose a phylogenetic scheme reflecting the processes of speciation and intraspecific diversification of the plague microbe, which can become a visual evolutionary model for improving the phylogenetic methodology.

Skin burns caused by various physical and chemical factors represent a significant medical problem due to their frequent occurrence, difficulty of treatment and high probability of complications. The study of destructive and regenerative processes occurring in the skin during burns of various nature requires the development of experimental models that allow analyzing the course of the healing process and identifying key factors contributing to it. This review examines models of thermal, chemical, and radiation burns of the skin in experimental animals. Techniques for creating lesions and methods of analyzing the condition of the skin, as well as the scope of application of these models, are described.

The expression of genes encoding myogenic regulatory factors – Myf5, MyoG, MyoD1a, MyoD1b, heavy (MyHC) and light (mlc2) myosin chains, as well as myostatin (Mstn1a) – was studied in pink salmon Oncorhynchus gorbuscha (Walb.) smolts caught in rivers during the period of migration for fattening to the White and Barents Seas. It was found that individuals from the Keret River had higher expression levels of the mlc2, MyHC, MyoD1a, MyoD1b and MyoG genes compared to those in the Varzuga River. It was shown that the smolts from the rivers of the White Sea basin – Indera, Keret and Umba, had higher expression values of the MyoD1b and MyoG genes, and in the Varzuga River – Myf5, in contrast to fish from the Voronya River of the Barents Sea basin. The highest level of expression of the Mstn1a gene was detected in pink salmon in the Voronya River. The obtained results indicate differences in the regulation of myogenesis in pink salmon smolts depending on the temperature and feeding conditions of habitat in different rivers.

Carbon tetrachloride (CCl4) disrupts the stable operation of biological membranes, causing disturbances in the lipid bilayer, as well as changes in the properties of membrane lipids. The protective effect of lipid complex isolated from the marine red alga Ahnfeltia tobuchiensis and the reference drug “Essentiale” was investigated on the plasma membranes of mouse erythrocytes, obtained in the modeling of toxic hepatitis induced byCCl₄. The lipid extract from A. tobuchiensis was not inferior in efficiency to the phospholipid preparation essenciale in restoring the indices of both membrane lipids and blood plasma lipids, as well as in normalizing the parameters of antioxidant protection of the organism. The membrane-protective effect of algal extract is due to its multicomponent composition including glyco- and phospholipids with predominance of polyunsaturated fatty acids of n-3 and n-6 families.

A modern pollen rain study along an altitudinal gradient in the Bale Mountains National Park (Ethiopia, East Africa) was carried out from 1580 m a.s.l. to 4110 m a.s.l. The contents of seven artificial pollen traps from seven plant communities corresponding to different altitudinal belts were investigated. Pollen spectra reflect dominant taxa of plant communities in most cases. However, the pollen of some widespread plants was underrepresented in the spectra due to low pollen production, flowering rhythms, and local features of the vegetation cover. Long-distance pollen transport was noted in all plant communities, but it was most pronounced in open communities.

Data on the thermobiology and daily activity of the Mediterranean tortoise Testudo graeca (Linnaeus 1758) in the North-East Caucasus are presented. The forms of daily activity with characteristics of body temperatures, external environment and thermoregulatory behavior are described. For morning and evening activity, primary and secondary thermoneutral behavior corresponds.

To reveal new functions of pannexin 1 in the mouse nervous system, cell types with the most pronounced expression of the gene encoding this protein were identified by bioinformatic analysis. It turned out that sensory neurons PSNP3 and PSNP6 of the dorsal root ganglia have the highest expression levels of Panx1, as well as high expression of purinoreceptor p2rx3, and other genes associated with the perception of pain and skin itch. The scratch reflex induced by compound 48/80 was suppressed in Panx1 knockout mice compared to wild-type mice, confirming the involvement of Panx1 in the purinergic regulation of sensory nerve fibers responsible for itch perception.

It has been experimentally observed that Ulva lactuca from the Barents Sea, is capable of surviving in a laboratory environment when the concentration of water soluble fractions of diesel fuel in water is up to 1 mg/l. A concentration of more than 4.9 mg/l was critical for algae. During these treatments, decreases in photosynthetic rate (2-16 times relative to the control) and the amount of photosynthetic pigments (more than 2 times of the control), an increase the hydrogen peroxide content and the activity of superoxide dismutase were observed in macrophytes. The number, biomass and size characteristics of heterotrophic bacteria associated with algae changed significantly. Thus, the high content of petroleum products in the environment limits the spread of U. lactuca algae, however, with minor contamination, they can actively participate in bioremediation processes.