Genetika

The lack of success in combating the spread of multidrug resistance in pathogenic bacteria forces the scientific community to analyze at a new level of knowledge the mechanisms, routes of spread and natural reservoirs containing bacteria that carry antibiotic resistance genes. The classical mechanism of resistance to aminoglycoside antibiotics (AG) is the modification of AG by enzymes, the most common and clinically significant of which are aminoglycoside acetyltransferases (AAC). In this study, genes encoding enzymes belonging to the AAC(2'), AAC(3), AAC(6') and Eis subfamilies were identified in the sequenced genomes of Streptomyces strains producing AG. Comparative analysis of amino acid sequences showed that the closest homologues for the identified AAC are acetyltransferases from other species of actinobacteria of the genus Streptomyces that do not produce AG (producers of other classes of antibiotics or not producing antibiotics). Comparative phylogenetic analysis of amino acid sequences showed that the enzymes AAC(2′) and Eis are homologues of the acetyltransferases AAC(2′)-I and Eis, previously identified in mycobacteria. The possible role of Eis acetyltransferases in the acetylation of various substrates upon entry into the human body through vesicles containing them is discussed.

The species of the genus Triticum and synthetic wheat produced with their involvement are a source of new genes contributing to the improvement of cultivated T. aestivum varieties. In this work, the nature of substitutions and translocations in hybrid lines derived from the cross of common wheat varieties with Triticum spelta and T. kiharae was studied. It was shown that in the chromosomes of the B genome (especially in chromosomes 4B and 7B), spelt fragments had, as a rule, a greater length than the fragments of synthetic wheat T. kiharae. In the lines produced with the involvement of synthetic wheat, recombination events occurred more often between A and A^t genomes compared to the B and G genomes of T. aestivum and T. kiharae respectively, indicating a closer relationship between the homeologous A/A^t chromosomes. The data obtained indicate that the length of introgressed fragments in the D-genome of all the lines studied is, as a rule, less than in A and B genomes. With regard to the lines developed with the involvement of spelt, a high meiotic index was noted (95.83–97.27%), which is determined by the close relationship of T. spelta and T. aestivum. The lines based on synthetic wheat had fewer normal tetrads (77.093.0%), which is due not only to the reduced homology of chromosomes between the genomes of their original forms, but also the reduced cytological stability of T. kiharae compared to the rest of parent genotypes. There were no significant disturbances in the process of gamete formation in introgression lines, and the meiotic index for the vast majority of genotypes was high (more than 90%). The studied lines are of interest for the selection of promising material characterized by economically valuable characters.

Recessive genetic mutations can cause various defects in cattle, leading to premature mortality and decreased herd productivity. This article is devoted to the study of the cattle population in the Sverdlovsk region for the presence of haplotypes HH1, HH3, HH4, HH6, HH7, BLAD, BDCMP, DUMPS, BC, FXID, CVM and comparison of the prevalence of these haplotypes in the periods 2008–2012, 2013–2017 and 2018–2023.

Human selection and natural selection have significantly increased the phenotypic and genetic differentiation of chicken breeds. Adaptation to environmental conditions, including acclimatization to harsh climates, has left “traces” of selection in the genome architecture of many breeds. Therefore, monitoring the genetic variability of small chicken breeds is an important part of breeding and conservation programs for poultry populations. Based on the results of genotyping breeds with the Illumina 60K Single Nucleotide Polymorphism (SNP) chip, a bioinformatics analysis was performed for egg-laying and ornamental breeds. Runs of homozygosity (ROH) were analyzed in egg-laying breeds – Czech golden (CZG), Leghorn Light Brown (Italian Partridge) (IP) and ornamental breeds – Holland White-crested Black (HWC) and Hamburg silver Spangled Dwarf (HSD). The average number of ROH in the chicken chromosomes varied between 200 ± 6 in PWC and 287 ± 5 in LLB, and the inbreeding coefficient was between 0.29 ± 0.04 in HWC and 0.50 ± 0.013 in HSD. Among the chicken breeds studied, out of 40 ROH islands identified, 8 identical were found in two or three chicken breeds. These ROH islands were located on GGA1, GGA2, GGA7, GGA11 and GGA25. Genes in the ROH islands were associated with chicken weight, fat metabolism, feed intake, egg yolk weight, feather pecking disorders, and molecular processes mediating DNA replication and mRNA processing. The phenomenon of identical ROH-islands in different breeds is discussed in the context of selection.

The association of polymorphic loci –924A>G (rs2232365) and –3279C>A (rs3761548) of the FOXP3 gene with the risk of developing essential arterial hypertension was studied. A total of 151 DNA samples from healthy individuals and 155 DNA samples from patients with EAH (stages I–II) were used. The frequency of occurrence of the –924A>G (rs2232365) polymorphic marker of the FOXP3 gene was almost the same in the groups of conditionally healthy individuals and patients with EAH (χ² = 0.07 and χ² = 0.42, p > 0.05, respectively, for alleles and genotypes). The frequency of the CC genotype for the –3279C>A (rs3761548) marker of the FOXP3 gene was higher in the group of patients with hypertension (χ² = 5.67, p = 0.018). An association was found between the carriage of the CC genotype for rs3761548 and the risk of developing hypertension (OR = 1.967 (95%CI 1.12–3.45)). The level of FOXP3 gene transcripts in peripheral blood leukocytes of healthy people did not depend on the carriage of allelic variants for rs2232365 and rs3761548 (p > 0.05). In carriers of the C allele for the polymorphic marker rs3761548, the content of IL-10 and IL-2 in the blood plasma was lower than in individuals with the AA genotype (p = 0.025, p = 0.017, respectively). The polymorphic marker –3279C>A of the FOXP3 gene is involved in the predisposition of Karelia residents to the development of EAH, probably through the effect on the level of IL-10 and IL-2.

Obesity and addictive eating behaviours represent significant causal factors in the development of type 2 diabetes mellitus. Genes encoding muscarinic and nicotinic receptors have been demonstrated to be significant associated with a wide range of psychiatric disorders. Consequently, these genes represent potential markers for the study of predisposition to both disturbed eating behaviour and type 2 diabetes mellitus (T2DM). A total of 992 DNA samples from individuals with T2DM and 1,023 DNA samples from healthy controls were examined. A DEBQ-based assessment of eating behaviour was conducted. The following polymorphic loci were investigated by real-time PCR: CHRNA5 (rs16969968), CHRNA3 (rs1051730), CHRNB4 (rs17487223), CHRM4 (rs206748), CHRNA3 (rs578776), CHRM5 (rs7162140), CHRM1 (rs2067477), CHRNA7 (rs3826029). The present study found an association between the T2DM and the following genetic variants: CHRNA5 rs16969968 (P = 0.00001, OR = 1.72), CHRNA3 rs1051730 (P = 0.00001, OR = 1.812), CHRM5 rs7162140 (P = 0.051, OR = 1.90), and CHRM1 rs2067477 (P = 0.003, OR = 1.41). It was shown an association between the AA haplotype (CHRNA5 rs16969968 – CHRNA3 rs1051730) and the AAT haplotype (CHRNA5 rs16969968 – CHRNA3 rs1051730 – CHRNB4 rs17487223) with the T2DM (P = 0.0004, OR = 1.37; P = 0.00005, OR = 1.34). The CHRNA3 rs578776, CHRNA7 rs3826029, CHRM5 rs7162140 and CHRM1 rs2067477 loci were found to be associated with Restrictive eating behaviour (P = 0.05, 0.003, 0.015, 0.05 respectively). Additionally, the CHRM1 rs2067477 locus was found to be associated with Emotional eating behaviour (P = 0.014), while the CHRNA5 rs16969968 and CHRNB4 rs17487223 gene polymorphisms were found to be associated with External eating behavior (P = 0.05, P = 0.036). The study revealed an association between polymorphic variants of the studied genes and both disturbed eating behaviour and T2DM.