Vol 55, No 7 (2019)

The paper presents a review of the results of molecular genetic studies of cognitive abilities. To date, a small number of genes responsible for normal cognitive functioning have been detected despite numerous studies based on the approach of candidate genes, genome-wide association studies, and linkage analyses. It should be considered that, even when the genetic variants were significantly associated with cognitive phenotypes, the sizes of the effect were usually very low (1–2%). However, large-scale genetic studies performed in the last few years significantly expanded the knowledge on the molecular basis of human cognitive abilities and made it possible to explain up to 20% of the 50% inheritance of intelligence.

Given is an overview of original publications devoted to the investigation of the honey bee genome. The history of honey bee genome studies and its characteristics are described. The results of genetic studies of honey bees using genome-wide data are presented. A special focus is put on the search for alleles associated with economically valuable, adaptive, and other important honey bee traits.

The IS630/Tc1/mariner superfamily of transposable elements (TE) is one of the most numerous and widespread among DNA transposons. The IS630/Tc1/mariner TE are divided into eight families: IS630, Tc1, mariner, pogo, maT, mosquito, plants, and rosa. The members of the rosa family (DD41D transposons) were allocated to a separate group relatively recently and are currently characterized in detail only in insects. It is known that the rosa family includes the Crmar-like and LTIR subfamilies. In the present work, the DD41D transposons were for the first time described in Mnemiopsis leidyi and Pleurobrachia bachei ctenophores. It was established that the elements of Mnemiopsis represent a new group, previously unknown, which we named leidyi. The members of this subfamily combine the traits inherent to two other subfamilies of DD41D transposons. The rosa elements belonging to the LTIR subfamily and having more extended DDE/D domains were detected in P. bachei.

We carried out the full genome sequencing of Bifidobacterium angulatum GT102. B. angulatum is rare species in the human gut microbiota, compared to the Bifidobacterium longum and Bifidobacterium adolescentis. In this regard, we investigated the genes of B. angulatum GT102 that are supposedly involved in the interaction with the host. Our analysis revealed an interesting histidine kinase HK10 belonging to the family of kinases, which can be bacterial adrenergic receptors. We discovered the PFNA cluster comprising a gene encoding fibronectin type III domain-containing protein having cytokine receptor motifs. The products of this cluster are possibly capable of interacting with human cytokines. Moreover genome of B. angulatum GT102 contains gene cluster, involved in the production of cell surface-associated capsular exopolysaccharides, that has unique genetic structure. The obtained results provided information regarding some undescribed characteristics of B. angulatum species and also help to better understand in a comparative aspect its communication characteristics.

Specific expression patterns of the FLC and VIN3 genes, which play a key role in the vernalization-mediated transition to flowering of A. thaliana plants from northern natural populations (Karelia), have been revealed. The differences in the FLC and VIN3 expression patterns during vernalization for populations represented by late-flowering forms, on one hand, and a population which was mixed with respect to the onset of flowering, on the other hand, were observed. A low level of FLC and VIN3 expression in plants from the studied populations prior to cold exposure was established. During vernalization, the FLC mRNA levels increased on the 10th and 20th day, followed by its decrease by the 30th day. Prolonged exposure to cold caused an increase in VIN3 expression with a peak in the populations represented by late-flowering plant forms on the 30th day of vernalization and in the mixed population for the flowering onset of plants on the 40th day. Specific patterns of FLC and VIN3 expression during vernalization was observed in S1 offspring of one early-flowering plant, while FLC expression in it changed according to classical scheme; i.e., the initially high level of FLC expression decreased in the process of vernalization. It is suggested that genetic and epigenetic mechanisms involved in controlling the flowering rate and the genes involved in this process may differ in plants from populations of different geographic regions.

The harlequin ladybird Harmonia axyridis forms stable natural populations in East Asia and southern Siberia and spreading invasive populations in Europe, Africa, North America, and South America in regions with temperate and subtropical climate. The polymorphism of the mitochondrial genome control region was characterized in population samples from populations of the native range and invasive range in Europe. The division of the native range into the eastern and western groups and the closeness of the invasive population to the eastern population group were confirmed. Haplotype diversity is maximal in the population of the Harmonia axyridis eastern population group and is reduced in the invasive population. The stability of the haplotype composition of the mitochondrial gene pool in the European invasive population in the process of the invasive range expansion was demonstrated.

WRN/RECQL2 plays a crucial role in DNA replication and the maintenance of genome stability. Inactivating mutations in RECQL2 lead to Werner syndrome, a rare autosomal recessive chromosomal disorder characterized by premature aging and associated with genetic instability and increased cancer risk. Whether heterozygous WRN mutations are associated with breast cancer risk has been a matter for debate. In the present study, we identified p.R1406X in the WRN gene in one family case with breast/ovarian cancer using whole exome sequencing. We have investigated the prevalence of this WRN mutation in a total of 828 breast cancer cases, 273 ovarian cancer cases and 445 controls from Bashkortostan Republic (Russia). Our results suggest that the p.R1406X mutation in the WRN gene is not associated with high breast cancer risk.

Experimental curves of the dependence of survival and delayed colony formation on UV light (254 nm) fluence for two wild-type strains of diploid yeast Saccharomyces cerevisiae capable of recovering from UV damage and their UV-sensitive mutants are presented. The dose–response curves were sigmoid for wild-type cells and rad6/rad6 and rad18/rad18 mutants, which were sensitive to UV irradiation by a factor of 2.2 and 1.5 for survival and 2.0 and 3.1 for delayed colony formation in comparison with the original strain (XS800). The T2 (rad2/rad2) strain was characterized by an exponential dose–response curve and was more sensitive to UV irradiation by a factor of 10.7 for survival and 7.0 for delayed colony formation compared to the original strain (T1). Delayed colony formation of all studied strains reached 100% with increasing UV light fluence. Unlike traditional representations, these data indicate that the delayed colony formation is mainly determined by cell ploidy and does not depend on the shape of the dose–response curves and UV sensitivity of cells.

Because of the involvement in motivational processes, opioid receptors are potential targets for apathy treatment in schizophrenia. We therefore searched for associations between the opioid receptor gene polymorphisms (OPRM1 (rs1799971) and OPRD1 (rs1042114, rs533123)) and apathy measured with the Apathy Evaluation Scale-S in a group of 284 schizophrenia patients. We analyzed individual genotypes, haplotypes, and the digenic interaction and observed nominally significant associations of rs1042114 genotypes and the rs1042114*rs1799971 interaction with behavioral apathy scores. The associations, however, did not withstand correction for multiple comparisons. Thus, the results did not provide enough evidence for the opioid receptor gene effects on apathy in schizophrenia patients.

Most sturgeon species are endangered and included in various Red Lists. The study of the spectrum of allelic frequencies can help to assess and monitor the state of their populations. I sequenced nine complete mitogenomes of the Amur sturgeon representing seven different variants of the mtDNA control region, one of which (SCH34) has an unusually high frequency in the population, according to the previously obtained data. No selectively significant substitutions in the protein-coding nucleotide sequences or substitutions in other functional regions of the mitochondrial genome were found that would distinguish the SCH34 mitotype from others. One of the three mitogenomes with the same SCH34 mitotype of the control region had a nucleotide substitution outside of the region. The calculated minimum evolutionary age of the SCH34 mitotype is approximately 4500–5400 years. The high frequency of SCH34 and mitotypes close to it (originating from it and differing by one or two nucleotide positions) in the contemporary Amur sturgeon population could not have been caused by either selection or human activity and was most likely due to one of its isolated populations going through the low population phase (bottleneck) in the past.