编号 1 (2023)

The content of thyroid and sex steroid hormones in the blood of immature and precocious trout Salmo trutta at the final stage of the formation of early maturing fishes (age 1+, 2+) in the population was determined. The formation period of early maturing males varies in different years in Alatsoya River (Karelia). Fish can reach sexual maturity at the age of 1+ or 2+. Immature and precocious trout at the age of 1+ and 2+ do not differ in the free and total triiodothyronine and free thyroxine content. Immature females and males aged 1+ and 2+ also do not differ in the level of sex steroid hormones. In contrast to immature brown trout, precocious males aged 2+ are characterized by an increased content of testosterone and a reduced level of estradiol-17β in the blood. It has been established that the final stage of the formation of early maturing fishes in the population is characterized by a weak involvement of the thyroid gland in the maturation process of males. Also, it was shown that the rate of conversion of testosterone to estradiol-17β in their blood was a significant decrease (4 times). This transformation in all studied females and males of brown trout is associated with their body length. The rate of formation of estradiol-17β in fish was increased with increasing of body length.

The genetic diversity and divergence of closely related species Oxytropis strobilacea, O. adamsiana, and O. vassilczenkoi series Strobilacei of the section Orobia (Fabaceae) from Asian Russia were studied using the data of nucleotide polymorphism of the psbA–trnH, trnL–trnF, and trnS–trnG intergenic spacers of cpDNA, as well as the ITS nrDNA. Most populations are characterized by an average and high level of chloroplast genetic diversity (h varies from 0.600 to 1.000). 65 chlorotypes were identified, no shared chlorotypes were found in taxa, and that confirms the status of O. vassilczenkoi as a separate species. Two phyletic lineages were found for O. strobilacea that indicates an intensively proceeding diversification process. Among the seven identified ITS ribotypes, one ribotype was shared for all three species, probably, due to their common origin and relatively recent divergence.

Successful invasion and adaptation of bacteria into lichen symbiosis requires the involvement of a number of physiological mechanisms that regulate interactions between bacteriobionts, mycobionts and algobionts and ensure the optimization of thallus growth and development. The genomes of two lichen bacteriobionts Lichenibacterium ramalinae and L. minor were analysed to identify those factors. No nodulation genes traditional for rhizobia were found. TIGR02302 protein has been suggested to have a similar function. Genes encoding proteins associated with the implementation of planktonic and biofilm phenotypes – flagellins and pilins – have been found. These genes have a high level of similarity with the genes of plant symbiont bacteria. Genetic determinants of virulence factors such as locus B invasion proteins, Integration host factor (IHF), sensory histidine kinases, siderophore receptor and transport proteins and monooxygenase of antibiotic synthesis (Abm) were found in the genomes of the studied bacteria. The listed genes have similarities with those in organisms forming associations of different degrees of association with plants. Based on the data obtained, the assumption of a priority association of bacteria of the Lichenibacteriaceae family with green lichen algae was suggested.

The ontogeny and structural organization of the rhizome of Nepeta transiliensis individuals in the high-mountain conditions of the Zailiyskiy Alatau have been studied. Various types of buds (renewal buds, dormant buds) take part in shoot formation, from which various types of elongated shoots are formed. Using the architectural approach to the description of plants, the main structural units – rhizome modules – are identified. Different branching of modules leads to the construction of different rhizome axes. In the rhizomatous axes, the angles of departure of the lateral modules from the maternal one differ, the development of the modules occurs sequentially from the renewal buds or with a delay from the dormant buds. The set of rhizomatous axes forms a branched rhizome complex and leads to the formation of rhizome tiers. In general, the rhizome of N. transiliensis is of the “intermediate” type, which combines the features of a geometric and non-geometric rhizome.

The effect of salt stress on the activity of decarboxylating malate dehydrogenases in maize leaves during the adaptive response of cellular metabolism to salt stress was studied. It was shown that excess NaCl concentrations cause an increase in the enzymatic activity of both NAD⁺-ME and NADP⁺-ME. The greatest contribution to the increase in the activity of NAD⁺-ME is made by the intensification of the expression of the nad-me2 gene. At the same time, the expression of nad-me1 under salinity increases to a lesser extent. Methyl-specific PCR showed an inverse relationship between the expression of nad-me2 and the degree of methylation of the promoter of this gene, while nad-me1 and nadf-me, apparently, are regulated by different mechanisms. A different functional role of each isoform of the studied malic enzymes in the adaptive response of cellular metabolism is assumed.

Probiotics modulate the immune response, displace pathogenic microorganisms from the gastrointestinal tract, and increase the survival rate of larvae. The object of the study was selected discus feeding offspring with an epidermal secret similar in a set of components to mammalian milk. Lactoferrin is found in the blood and skin secretions of discus, it has antibacterial, antifungal, antiviral and antiparasitic activity. The addition of the probiotic ”Subtilis-C” to the diet of nursing discus increases the production of lactoferrin in the epidermal secretions of parents, and also contributes to better survival of larvae and fry of fish.

The paper presents data on the population structure, morphometric features of plants and seeds and some aspects of reproductive biology (fruit set, seed productivity) of Dactylorhiza fuchsii (Druce) Soó (Orchidaceae) on the northern border of its distribution area (the Komi Republic, northeast Russia). We found statistically significant decrease of seed size and flowers number per inflorescence from south to north within of the species distribution area. In the Komi Republic, the seed productivity of Dactylorhiza fuchsii was found to be lower than in the southern parts of its distribution area: one fruit contains an average of 2900 ± 80 seeds, the average real seed productivity of the generative plant is 24800 seeds. Despite the declination of some reproductive success indicators, in the northern territories the species forms quite large, well-regenerating populations.

The PCDD/F profiles in free-range chicken eggs and corresponding soils from private households in Vietnam were compared. The main trend in the change in the profile of PCDD/F congeners during bioaccumulation in eggs is the relative increase in the contributions of low-chlorinated congeners and the decrease in the contribution of OCDD. Differences in the profile of hexachlorinated congeners in eggs and soil may indicate additional sources of PCDD/F in eggs other than soil.