Vol 21, No 3 (2023)

BACKGROUND: The beginning of the life cycle of a leguminous plant in its natural habitat is usually associated with interaction with nodule bacteria in order to form a nitrogen-fixing symbiosis. In a short period of time, a plant needs to “choose” suitable microsymbionts for itself. Since a wide variety of rhizobial strains is formed in the rhizosphere of legumes, the choice made by the macrosymbiont will further influence its productivity.

AIM: The purpose of our work was to compare the principles of selection by different plants of their microsymbionts at different stages of plant development.

MATERIALS AND METHODS: Nodule bacteria Trifolium hybridum L. and Galegaorientalis Lam. were taken into the study. Their genetic diversity was studied by the RAPD method, a phylogenetic analysis of bacteria and their symbiotic nodC and nifH genes was carried out, and their nitrogen-fixing activity was assessed.

RESULTS: It was found that the rhizobia that form nodules on the roots of the studied leguminous plants at different stages of their vegetation have certain patterns. It was found that the highest polymorphism and specific nitrogen-fixing activity are characteristic of bacteria obtained from nodules formed at the initial stage of vegetation.

CONCLUSIONS: We assume that the plasticity of the rhizobia genome gives the host plant the ability to more flexibly adjust its nitrogen-fixing apparatus to changes in growing conditions.

BACKGROUND: The analysis of ROH distribution is an important focus of genetic resource conservation programs of cattle. Characterization of ROH-islands allows to identify genetic factors affecting productivity traits of dairy cattle.

AIM: was to analyze intra-breed genetic diversity and population structure of Ayrshire cattle, based on data on distribution of homozygosity patterns, as well as to identify loci associated with selection intensity and utility traits.

MATERIALS AND METHODS: ROH distribution data were obtained using whole genome genotyping on Illumina BovineSNP50 (50K) DNA chips (Illumina Inc., USA). The object of the study was the DNA of Ayrshire cows (600 cows), which belonged to farms with different levels of selection and breeding work.

RESULT: The results of our studies showed a generally similar level of inbredness of the analyzed Ayrshire cattle herds. The homogeneity of the population is confirmed by a large number of animals (72.83%) with F_ROH values between 0.10 and 0.20. Cluster analysis revealed consolidated groups of individuals, due to their ancestral origins. The discovered ROH-patterns included 268 genes, 32 of which were involved in regulation of the synthesis of protein and fat milk components. The results obtained may be used in breeding programs for Ayrshire cattle in Russia.

CONCLUSIONS: The Russian population of Ayrshire cattle is distinguished by unique qualities in protein and fat milk composition and genome architecture, while maintaining genetic diversity and insignificant traces of Ayrshire cattle gene pool.

BACKGROUND: Phlorotannins are unique phenolic compounds produced by brown algae. Due to their considerable biological activity these metabolites are extensively studied in the context of medicinal applications. However, to date, no studies addressed potential genotoxicity of phlorotannins.

AIM: The objective of this research is an assessment of mutagenic activity of intracellular and cell wall (CW) bound phlorotannins of three brown algal species.

MATERIALS AND METHODS: Mutagenicity of phlorotannin extracts of Desmarestia aculeata, Fucus serratus, and Ectocarpus siliculosus was assessed by the Ames test, carried out using three tester strains of Salmonella typhimurium (TA97, TA98, and TA100) with and without metabolic activation.

RESULTS: Intracellular phlorotannin extracts of all tested algae showed relatively low values of minimum inhibitory concentration against S. typhimurium (20–30 μg/ml), with extract of D. aculeata being the most toxic. Intracellular phlorotannins of F. serratus and CW-bound polyphenols of E. siliculosus demonstrated moderate mutagenic activity in the Ames test inducing frameshift mutations with the number of His⁺ revertants more than twice higher compared to the control. The phlorotannin extracts of D. aculeata showed no mutagenic activity.

CONCLUSIONS: The brown alga D. aculeata may be regarded as a promising source of phlorotannins for medical applications, as its phlorotannin-enriched extracts have high antibiotic activity and are not mutagenic.

The review summarizes ideas about the role of polymorphic variants of redox-sensitive genes that regulate the development of oxidative stress in obesity and associated metabolic diseases. The concept of oxidative stress, activated oxygen metabolites (AOM), which include reactive forms of oxygen, nitrogen, and chlorine, is considered, and an idea of the antioxidant system and its enzymatic link is given. The important role of gene polymorphism of AOM-producing enzymes — CYBA, CYBB, MT-ND1/2/4L, MT-CO1/3, XOR, CYP, NOS2/3, MPO — in the induction of oxidative stress in obesity has been shown. The dualism of AOM in obesity is emphasized: on the one hand, they are necessary for normal adipogenesis and signaling, and, on the other hand, they play a trigger role in the development of oxidative stress. It has been demonstrated that an imbalance in antioxidant system in obesity and metabolic disorders may be associated with variability in the genes of key antioxidant enzymes and proteins — SOD1/2/3, CAT, GPX1-8, GSR, GSTP1, GSTM1, GSTT1, PRDX3, TXNIP, HMOX1, NQO1, NFE2L2, KEAP1. The critical role of polymorphism in the Nrf2 transcription factor gene, the main regulator of redox homeostasis under physiological conditions and in obesity, has been demonstrated. It has been demonstrated that disruption of redox homeostasis due to genetic variability of the prooxidant-antioxidant system contributes to the development of the pathological obesity phenotype. Understanding the genetic mechanisms underlying oxidative stress in obesity and metabolic diseases is necessary to expand knowledge about the mechanisms of pathogenesis of these diseases and to develop effective methods for their correction.