Volume 60, Nº 12 (2024)

Erroneous pedigree records reduce the quality of breeding work with cattle; therefore, parentage exclusion expertise has become an integral part of breeding work. For many years on the territory of the Russian Federation, the expertise was carried out using immunogenetic markers, but the improvement of technologies and tightening of regulatory requirements has led to the process of replacement of immunogenetics by microsatellite markers. At present there is no domestic protocol clearly regulating the procedure of cattle parentage exclusion expertise using microsatellite loci, which makes laboratory work more difficult. In particular, the requirements for the number and nomenclature of genetic markers which are used in the genetic expertise are only available for cattle, embryos and semen products being transported across the Eurasian Economic Union. There are no regulations for errors I (false positives) and II (false negatives) types control, which must be taken into account when forming expert judgements. In this paper we will review the approaches to addressing these issues proposed by the International Society for Animal Genetics (ISAG), the International Committee for Animal Recording (ICAR), the Collegium of the Eurasian Economic Commission, as well as domestic regulatory documents governing the production of forensic medical tests related to parentage exclusion expertise. Based on the results of the review, a nomenclature of microsatellite markers and a parentage exclusion protocol will be proposed, in which errors I and II type control are carried out. Special attention will be paid to the description of the sources of II type error and the necessity of its control.

Under normal conditions and when exposed to low doses of mutagens, DNA damage tolerance systems (DDT) are a key way to combat DNA damage in bacterial and eukaryotic cells. Two different DDT pathways, erroneous (translesion synthesis – TLS) and error-free (recombination), operate in all eukaryotic organisms. TLS involves the protein complex polymerase zeta (Polζ) (encoded by the genes REV1, REV3 and REV7), and polymerase eta (Polη) (encoded by the RAD30 gene); these polymerases are conserved from yeast to humans. We have shown that at low levels of UV radiation doses, a decisive role in mutagenesis is played by the high activity of Poly, which bypasses the overwhelming number of DNA damage that got in the way of the replication machine. Both in the case of irradiation with high and low doses of UV rays, checkpoint plays an important role in induced mutagenesis. However, the roles of genes involved in the regulation of UV-induced mutagenesis at low and high doses often differ. Inactivation of the RAD30 gene at low doses leads to an increased level of induced mutagenesis, and at high doses it practically does not differ from the level of the wild-type strain. Deletions of the HIM1, HSM3 and HIF1 genes, on the contrary, reduce the high level of mutagenesis characteristic of high doses to the level of the wild-type strain at low doses. These differences characterize the local and global checkpoint.

The dynamics of the transcriptional activity of one of the key genes of the circadian network, CCA1, was analyzed under conditions of a natural light photoperiod of a long day (16L : 8D) and under an inverted light regime (8D : 16L) in A. thaliana plants of the northern natural population (Karelia). It has been shown that under conditions of an inverted shift in the light regime, there is a sharp increase in the expression of this gene with a phase shift in the circadian rhythm by 2 hours. The level of CCA1 transcriptional activity was almost two times higher compared to the natural light conditions. At the same time, the endogenous rhythm of the gene was preserved, but with a smaller amplitude. With age, 30-day-old plants grown under inverted conditions experienced a loss of endogenous CCA1 circadian rhythm. The results obtained allow us to conclude that the circadian rhythms of A. thaliana, northern natural populations, probably play an important role in adaptation to changing light conditions, and that one of the key clock genes, CCA1, plays a significant role in this process.

Data on the structure and variability of the nucleotide sequence of the mtDNA cytochrome b gene of the northern pike Esox lucius L. from the rivers of the Kolyma, Volga, Don basins and the Anadyr River were obtained. Unique haplotypes were found, indicating limited gene flow between the studied populations. Northern pikes from the Volga and the Anadyr have a high level of genetic diversity. Low genetic diversity was noted in some populations of the Kolyma and Don basins. Phylogenetic analysis of the nucleotide sequences of the cytochrome b gene showed the presence of three genetic lines – A, B, V, having a common root of origin. The high level of differentiation of the identified lines is apparently caused by the long-term reproductive isolation of the northern pike in several refugia, which were the source for the circumpolar distribution of this species.

Using 14 microsatellite markers (BM1824, BM2113, CSRM60, CSSM66, ETH3, ETH10, ETH225, ILSTS006, INRA023, SPS115, TGLA53, TGLA122, TGLA126, TGLA227), samples of Ukrainian Grey cattle herds of the M.F. Ivanov Institute “Askania-Nova” (Kherson region) (n = 101) and experimental farm of Cherga (Altai Republic) (n = 41). When considering Wright's F-statistics for the studied loci, the value F_IS = –0.0285 indicates an excess of heterozygous genotypes in the population of Ukrainian Grey cattle, with a low probability of encountering alleles of the common ancestor F_IT = 0.1161, and the level F_ST = 0.1394 indicates an average divergence of subpopulations, the largest contribution to which is contributed by the Eth3 locus. At the same time, the number of detected polymorphic loci – 95.64%, the level of allelic diversity – A_R = 7.66 and genetic diversity – H_E = 0.76 were higher in the Altai subpopulation than in the Kherson subpopulation – 58.13%, 4.41, 0.61, respectively. At the same time, the Kherson herd was characterized by better evenness, homogeneity and consolidation, which allows us to consider it as a source of valuable breeding material for breeding the Ukrainian Grey breed.

The gene pools of Siberian peoples are a potential source of data on the compositions of haplotypes of polymorphic gene variants formed during the evolution of populations under the influence of a specific set of natural and climatic factors, in conditions of relative geographical and cultural isolation, as well as traditional subsistence practices. In order to study genetic adaptation to insufficient supply of vitamin D (low level of insolation and availability of nutrients containing cholecalciferol and ergocalciferol) in samples of indigenous Turkic-speaking (Teleuts, Tomsk Tatars, Shors) and foreign East Slavic (Russians) population of Siberia, a study of the frequencies of polymorphic variants (14 SNPs) of genes responsible for transport of vitamin D – GC (Group-Specific Component), the structure of its main receptor – gene VDR (vitamin D receptor) and the RXR receptor (retinoid X receptor) in form of genes RXRA and RXRG was conducted. The total sample size was 411 people. The analysis of polymorphic variant frequencies demonstrated specific features of the gene pools of Siberian indigenous populations compared to the Russian population, global frequencies and frequencies characteristic of populations of Europe and East Asia. In pairwise comparison with the sample of Russians, statistically significant differences were found in terms of frequencies rs7041 (Shors), rs3847987 (Tomsk Tatars, Teleuts, Shors), rs9409929 (Tomsk Tatars, Teleuts), rs877954 (Tomsk Tatars), rs283696 (Teleuts). According to data of average genetic distances (d), the minimum distances were noted between Teleuts and Tomsk Tatars. The sample of Russians in general turned out to be the most distant in the genetic space of the studied peoples of Siberia. The study of haplotype frequencies of polymorphic variants of vitamin D transport and receptor genes demonstrated the accumulation of SNP in the indigenous gene pool associated, according to the literature, with a higher levels of serum vitamin D. According to the GC and VDR genes, the haplotypic profile of polymorphic variants was characterized by pronounced specificity and differed in composition from that of the Russian population. The study allows us to conclude that structure of gene pools of indigenous peoples of Siberia retains a distinctiveness that reflects the history of their composition and demonstrates the features of the genetic adaptation of indigenous populations to environmental conditions.

A theoretical analysis of the surname state of the population (the vector of namesake concentrations in the male component of the population) and its dynamics as a result of random surname drift is presented. An approximation of such a process by the Wright-Fisher model of a population with non-overlapping generations without selection pressure is used, i.e., an approximation by a sequence of nested random samples with the replacement from fathers’ surnames in the population. The sample size is N/2 according to the size of the male component in the population of size N. In the same population, processes of random drift of both surnames and genes simultaneously occur. Their cardinal difference is that the sample size of surnames is four times smaller than the sample size of autosomal locus alleles. The analysis of random drift is simplified when moving from concentration coordinates to the square roots of them. As generations change, the state receives a sample deviation, measured by angular distance, and its mean square gives the rate of divergence, stabilizing in the new coordinates. An adaptation (in relation to the analysis of surname drift) of a known in population genetics result about the nature of divergence at a stage of a relatively small number of generations compared to the size of the population is given. The divergence of surnames occurs four times faster than the divergence of allele concentrations.

The offspring sex ratio of the Demoiselle crane (Anthropoides virgo Linneaus, 1758) was analyzed in two remote breeding groups of the European (Republic of Kalmykia) and Asian (Republic of Buryatia) parts of the range in 2023. Using the molecular genetic marker EE0.6, the sex was determined in 46 chicks (24 males and 22 females) from 30 broods. In the total sample, the deviations from equal proportion of females and males were not significant (0.521, P = 0.092). The sex ratio in each of the studied breeding groups also did not statistically differ from the parity, although males (0.650, P = 0.523) prevailed in two-chick broods and in general in the offspring of the Demoiselle crane in Kalmykia (0.423, P = 0.781), while females prevailed in two-chick broods and in general in the offspring of the Demoiselle crane in Buryatia (0.423, P = 0.781). The obtained data support the strategy of reproduction of parity number of both sexes in the Demoiselle crane and may indirectly indicate that in this species the energy cost on raising males and females is equal, and the pressure of environmental conditions is not so strong to cause bias of the existing balance towards any sex.