Vol 61, No 9 (2025)

Nonspecific (polymorphic) teratozoospermia is a common male fertility, when the proportion of morphologically normal spermatozoa is lower than the reference values, while several types of morphological abnormalities of spermatozoa in different proportions are observed in the ejaculate sample. Polymorphic teratozoospermia is known to be resuled from both negative environmental and lifestyle factors, as well as the presence of pathogenic variants of certain genes. However, little attention is paid to the study of the genetic causes of polymorphic teratozoospermia. In this review, for the first time, as a result of an analysis of the published literature, as well as information from the databases Malacards, OMIM, KEGG, CTD, and DisGeNET, the evidence on 85 pathogenic variants of 51 genes related to the development of polymorphic teratozoospermia in humans has been obtained and systematized. According to the functional annotation of genes and the analysis of published literature, the products of these genes are involved in the organization of the components of the cytoskeleton of the spermatid – acroplaxome and perinuclear theca, which ensure the formation of the acrosome and the interaction of the acrosome vesicle with the nucleus, as well as intracellular transport of molecules, regulation of protein expression and degradation, and chromatin rearrangement during spermiogenesis. In addition, pathogenic variants of some genes lead to a decrease in the effectiveness of the natural antioxidant protection of cells and, as a result, the manifestation of teratozoospermia. This information can be useful for the diagnosis and choice of treatment tactics for polymorphic teratozoospermia, which can be caused by both genetic causes and the influence of negative environmental and lifestyle factors.

Restriction-modification (RM) systems play a crucial role in protecting prokaryotes from the foreign DNA. Genes encoding antirestriction proteins such as ArdA and ArdB are often among the first genes to enter the cell upon infection. Recent studies demonstrated that DNA-mimicking ArdA proteins exhibit specificity to RM systems, meaning they can mimic specific DNA sequences. Moreover, this specificity can be achieved using recently discovered very small DNA-mimicking proteins called sArdA. This suggests promising applications for these DNA-mimicking “almost peptides” in specifically interacting with DNA-binding proteins to regulate intracellular processes. Another class of antirestriction proteins ArdB, appears to act as a universal DNA-binding agent, inhibiting restriction activity of all known type I RM systems, as well as CRISPR/Cas3. These findings could potentially enhance transformation efficiency in hard-to-transform strains.

At present, the development of environmentally friendly bioinsecticides for the control of agricultural insect pests and synanthropic insect species is of particular relevance. One promising approach is to use double-stranded RNA complementary to a vital insect gene to knockdown that gene through an RNA interference mechanism, resulting in the death of the insect. Using Drosophila melanogaster as a model object, one gene, Actin 5C, was selected from six paralogous Drosophila actin genes based on the fact that knockdown of this gene in most Drosophila tissues results in insect death. A double-stranded RNA complementary to the Actin 5C gene of the German cockroach, Blattella germanica, was microinjected under the cuticle. RNA interference of this gene has been shown to kill cockroaches within few weeks. The prospects of using double-stranded RNA complementary to the Actin 5C gene as an insecticide are discussed.

Primers for amplification of six minisatellite and one microsatellite loci were developed based on the mitochondrial genome of Norway spruce. Their testing on six populations of Siberian spruce and the northern cluster of Norway spruce (120 trees) revealed from three to seven alleles. The multilocus combination of six minisatellites yielded a total of 27 haplotypes. The populations had from two to nine haplotypes, but almost no common ones, and were divided (R_CT = 0.77) into three groups – European Russia, the Urals and the Siberian spruce population (Altai). In a population located at the alpine tree line in the Southern Urals, the haplotypes were not located randomly, which demonstrates the possibility of using the developed markers to identify groups of maternally related trees and study the process of tree colonization of the open areas. In the population from the southern cluster of Norway spruce (Carpathians, 24 trees), only one of the markers had stable amplification and was variable (six alleles).

Fish of the genus Nothobranchius are a unique model object of longevity genetics due to their short life span. They are especially promising for testing geroprotectors. However, the small size of the fish does not allow for dynamic evaluation of parameters reflecting aging rate and response to experimental effects on the same individual. The aim of the study was to develop an approach for minimally invasive monitoring of age-related changes in a model of Nothobranchius guentheri. The caudal fin transcriptomes of female and male Nothobranchius guentheri of different ages, including those regenerated after resection, were sequenced. Differential gene expression was analysed. Gene expression profiles in caudal fins of Nothobranchius guentheri, regenerated once or twice, do not differ significantly when compared with intact fins. The results obtained open new prospects for minimally invasive monitoring of age-dependent changes in the organism at the molecular-genetic level, including the study of potential geroprotectors.

Coronavirus disease COVID-19 is an infectious viral disease that has rapidly spread throughout the world and developed into a global pandemic in 2020. The clinical spectrum of COVID-19 is diverse and range from asymptomatic infection to respiratory failure and death. The etiology of COVID-19 clinical course is not well understood. The role of many factors is assumed, including the genetic characteristics of the individual. Replicative association analysis COVID-19 severity with the single nucleotide variant (SNV) rs73064425 of the LZTFL1 gene was performed. According to GWAS this SNV is associated with COVID-19 severe form. The polymorphism rs73064425 was showed a significant association with COVID-19 severe form in the Russian population of Tomsk. Possible mechanisms of the studied SNV involvement in the disease pathogenetics are discussed. Frequencies variability of the risk allele T rs73064425 was found in populations of the world.

COVID-19 is a severe acute respiratory infection caused by the SARS-CoV-2 virus. Research in the field of host genetics contributes to the discovery of new genomic markers of coronavirus infection progression. In this article, a method for multiplex genotyping of polymorphic variants of genes associated with the severity of COVID-19 has been developed, based on multilocus PCR and MALDI-TOF mass spectrometry of DNA molecules. The frequencies of 45 single nucleotide polymorphisms of COVID-19 candidate genes in a population sample of Russians from Tomsk are characterized. The results are compared with data for populations from the 1000 Genomes Project.