Vol 59, No 11 (2023)

The egg production of chickens is a complex polygenic type of inheritance and is controlled by many genes. The laying performance of chickens is the result of a complex process regulated by the hypothalamic-pituitary-gonadal system. This review summarizes the information on the effect of polymorphisms of follicle stimulating hormone (FSHR), luteinizing hormone (LHCGR), progesterone (PR) and prolactin (PRLR) receptor genes on the egg production and reproductive performance of chickens. The data presented show that the polymorphisms of these genes are promising for use in breeding programs to improve egg production and reproductive performance of chickens.

There has been a wide variation in the content of micro and macro elements, both between subspecies and within rice species and varieties. Magnesium as a cofactor is involved in more than 300 enzymatic reactions and is necessary for growth and development of both plants and humans. It affects carbohydrate and protein metabolism. Both adenosine triphosphate (ATP) production, nucleotide and glucose synthesis, and lipid oxidation regulation depend on its concentration. Calcium is also essential for the formation of cell wall structure and cell division. High concentrations of calcium change the composition and condition of red blood cell membranes and cell morphological characteristics. At the same time the variability in signs of domestic rice varieties has not yet been studied. There have been no studies on the localization of chromosomal regions responsible for the formation of traits of magnesium and calcium content in rice samples. Wide variation in calcium content (0.07–2.33%) and magnesium content in rice samples (2–14%) was established. Contrasting groups of varieties and sources by signs were identified. A search for chromosomal regions determining the quality of domestic samples was carried out using 58 molecular markers distributed across the rice genome (SSR). The data on phenotyping of native rice varieties by quality signs were used to divide them into groups with maximum trait value (1) and minimum trait value (2). The relationship between phenotypic manifestation of the trait and the genotype of the sample was established: by means of analysis of variance. Eight loci determining magnesium and calcium content in native rice varieties – were identified. The loci determining magnesium content are located on chromosomes 5, 6, 7, 8. Four loci associated with calcium content were identified two on the second chromosome and one each on the eighth and fifth chromosomes. On the fifth chromosome, it is located (RM 13, 28.6 cM) in close proximity to the RM 405 marker region (28 cM), which is connected with magnesium content.

The results of the morphological and genetic analysis of populations/forms/species of tanned whitefish from the middle and lower reaches of the river are presented. Lena, and adjacent rivers. There are reasons to believe that, despite the significant heterogeneity of whitefish in Siberia, a small number of stable forms/species inhabit the water bodies of the Siberian Arctic. These are East Siberian (C. lavaretus pidschian n. brachymystax), glacial plain (C. lavaretus pidschian n. glacialis), and Yukagir whitefish (C. lavaretus pidschian n. jucagiricus), as well as their hybrid populations. The glacier-plain whitefish and its derivatives differ from the East Siberian whitefish in plastic features, but they are identical in meristic ones. Molecular genetic studies have shown that in most glacier-plain whitefish form extensive loosely connected networks of haplotypes, which corresponds to the long-term existence of populations in favorable conditions. The East Siberian whitefish haplotypes are closely related to the whitefish haplotypes from the water bodies of Southern Siberia and have a radial structure. Such a structure of median networks indicates a recent decline in the number of East Siberian whitefish followed by expansion, which is directly related to the events of the Quaternary glaciations.

For the first time, an analysis of the genetic diversity of the Osetin sheep breed was performed using genome-wide SNP profiles in a comparison with other Russian coarse wool breeds. We established that the Osetin breed has high genetic and allelic diversity indicators. For the first time, the recent and historical population effective sizes of the Osetin breed were calculated. Close genetic relationships between the Osetin and Karachaev sheep breeds were shown, that is confirmed by the low value of differentiation (F_st = 0.009) and the formation of a joint cluster at the Neighbor Net graph. The similarity of the population structure of the Osetin and Karachaev breeds was revealed as well.

The most sensitive biomolecule under radiation exposure is DNA, whose damage manifests itself in the form of chromosomal aberrations (CA). The processes of DNA methylation, which are involved in the regulation of gene expression, replication, DNA repair, etc., are also affected by gamma radiation. The aim of the study was to evaluate the relationship between the degree of DNA methylation and the frequency of CA after acute in vitro irradiation of human blood lymphocytes with gamma radiation. The study involved 10 conditionally healthy workers of the Siberian Chemical Combine, in whose blood lymphocytes the degree of methylation of CpG-dinucleotides (wide-genome bisulfite sequencing, XmaI-Reduced representation bisulfite sequencing – XmaI-RRBS) and the frequency of CA (cytogenetic study) after acute in vitro blood irradiation with doses of 0 and 1.5 Gy were evaluated. After acute exposure to gamma radiation in lymphocytes, the frequency of aberrant cells, dicentric chromosomes, chromatid and chromosomal fragments increased. Correlation analysis of the status of CpG-dinucleotide methylation and the frequency of CA revealed changes in the degree of methylation of 97 genes, which strongly correlated positively (56 genes) or negatively (41 genes) with an increased frequency of CA. A primary genome-wide screening of genes whose methylation is correlates with a high frequency of CA was carried out. Many of the identified genes are promising as potential markers of radiation exposure and to study the mechanisms of formation of radiosensitivity of the body and radioresistance of tumors during radiation therapy.

Single nucleotide polymorphism (SNP) is a change of one nucleotide by another. This change often leads to an emergence (or disappearance) of a site recognized by a certain restriction endonuclease. As a result amplification of DNA fragment using primers surrounding SNP point (containing either N1 or N2 nucleotide) followed by hydrolysis of the amplicon with this restriction enzyme will be different for three possible variants in a diploid genome (genotypes N1/N1, N1/N2 and N2/N2). This method of restriction fragments length polymorphism (RFLP) is widely used in the genetic studies. Earlier we have developed GlaI- and FatI-PCR analyses methods which allowed to carry out real-time PCR and showed it applicability for SNP determination. In the current work a new way to determine the single nucleotide polymorphism G/C by the Bst2UI-PCR analysis is proposed. GlaI- and Bst2UI-PCR analyses have been used to determine the frequency of G/C polymorphism variants at the chr20:37352001 position (according to GRCH38.p14 genomic assembly) in the blood DNA samples of 161 donors. The study included: 1) the isolation of leukocyte DNA from blood cells; 2) GlaI- and Bst2UI-PCR analyses of the DNA fragment chr20:37351957-37352083, 3) determination of cytosine and guanine at the chr20:37352001 position in the analyzed DNA preparations, and 4) comparative analysis of the obtained results. It has been shown that 68 donors (42.2%) have a heterozygous set of G/C at the chr20:37352001 position, 89 donors (55.3%) are homozygous by G, and 4 donors (2.5%) are homozygous by C. Thus, taking into account that blood cells have a diploid set of chromosomes, G to C replacement occurs in 76 out of 322 analyzed cases (23.6%). At the same time, from the results obtained it follows that the cytosine residue complementary to G at the chr20:37352001 position exists in methylated form (5-methylcytosine) in most of the DNA molecules, both in homo- and heterozygotes. The proposed method of Bst2UI-PCR analyses extends the possibilites of SNP determination using real-time PCR.

In the sample of male residents of St. Petersburg, Y-chromosome haplogroups were determined by genotyping 18 STR Y-chromosome (DYS389I, DYS389II, DYS390, DYS19, DYS385A, DYS385B, DYS456, DYS437, DYS438, DYS447, DYS448, DYS449, DYS391, DYS392, DYS393, DYS439, DYS635 and DYS576) and data on genetic demography were collected by means of a questionnaire. The distribution of Y-chromosome haplogroups in St. Petersburg residents generally corresponds to the published data on Russian gene pool, with the most frequent haplogroups R1a, R1b, E1b1b1, N, T, I1, I2, J1 and J2, and with the predominance of haplogroup R1a. The presence of “southern by origin” haplogroups (C3, G2a, G2c, J1, J2, L, O2, O3, Q, R2 and T) entering the megalopolis with a flow of migrants, with a total frequency of 16% (in Moscow – 18.1%) was noted. A comparative analysis of the frequency distributions of Y-chromosome haplogroups in residents of St. Petersburg and Moscow revealed statistically significant differences in the frequency of haplogroup E1b1b1, and differences in the ratio of I1 and I2, determined by geographic position. Based on the survey data, a sample of Russian men who had no ancestors of another ethnicity in the male line in the two previous generations was formed. Significant differences in the frequency of “southern-origin” haplogroups were established between the initial sample of residents of St. Petersburg (16%) and the sample of men with Russian ancestors in two previous generations (4.1%). The obtained result confirms the spectrum of haplogroups of “southern origin” as penetrating into the gene pool of the population of a megalopolis with migrant flows and indicates the need for genetic and demographic questionnaires when forming reference databases for a megalopolis, as well as for their timely updating due to changes in the gene pool under the influence of migration.

Metapopulations with typical for human populations hierarchical subdivision into parts (subpopulations) are considered, corresponding to classifications based on administrative-territorial division (say, village, village council, district, region, and so on) or on a genealogical approach based on ethnogenesis, as well as on other principles of biological classification. The purpose of this work is to analyze the general properties of the distribution of the surname concentration over subpopulations in their hierarchical structure. Attention is focused on the description of the surname divergence of subpopulations, as an indicator of which the total probability of two person with different surnames encounter is considered, which is understood as the probability of the encounter in a randomly chosen subpopulation, a unit of observation, from metapopulation with a hierarchical structure. Its decomposition by hierarchy levels is obtained, which generalizes the Wahlund effect in population genetics. The total probability of non-isonimic encounters in a hierarchically subdivided metapopulation is less than the probability of random encounters in it by the sum of the average surname concentration intragroup variances corresponding to separate levels. Such properties are purely statistical characteristics of the hierarchical structure, and not a feature of a particular population system, and are not derived from the regularities of one or another model of microevolution. They are computationally formulated in the same way for any hierarchical system, although in the general case they do not coincide quantitatively. The results obtained refer to rural and urban hierarchical metapopulations as separate components of the entire population.

The paper presents the results of candidate genes search for live weight is southern meat sheep breed. The sample of 48 ewes weighed in the age of 24 months and elder was genotyped on Ovine SNP 50 Genotyping BeadChip array. Using a fixation in dices method (F_st), wedetected 55 polymorphisms associated with live weight. 10 SNP swith the highest F_st value were selected to check the effect on the trait under investigation. All the candidate genes showed the association witht helive weight trait. It’s interesting to not ethatin the NDFIP1 gene there were detected two significant SNPs with a high F_st value.