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Оригинальный русский текст: https://vavilovj-icg.ru/2018-year/22-7/

 

Vol 22, No 7 (2018)
View or download the full issue PDF (Russian)

Articles

PLANT GENETICS

 
756-765 927
Abstract

Transcription factors (TFs) play a central role in the gene regulation associated with a plant's development and its response to the environmental factors. The work of TFs is well regulated at each stage of their activities. TFs usually consist of three protein domains required for DNA binding, dimerization, and transcriptional regulation. Alternative splicing (AS) produces multiple proteins with varying composition of domains. Recent studies have shown that AS of some TF genes form small proteins (small interfering peptide/small interfering protein, siPEP/siPRoT), which lack one or more domains and negatively regulate target TFs by the mechanism of protein interference (peptide interference/protein interference, PEPi/PROTi). The presence of an alternative form for the transcription factor CCA1 of Arabidopsis thaliana, has been shown to be involved in the regulation of the response to cold stress. For the PtFLC protein, one of the isoforms was found, which is formed as a result of alternative splicing and acts as a negative repressor, binding to the full-length TF PtFLC and therefore regulating the development of the Poncirus trifoliata. For A. thaliana, a FLM gene was found forming the FLM-б isoform, which acts as a dominant negative regulator and stimulates the development of the flower formation process due to the formation of a heterodimer with SVP TF. Small interfering peptides and proteins can actively participate in the regulation of gene expression, for example, in situations of stress or at different stages of plant development. Moreover, small interfering peptides and proteins can be used as a tool for fundamental research on the function of genes as well as for applied research for permanent or temporary knockout of genes. In this review, we have demonstrated recent studies related to siPEP/siPROT and their involvement in the response to various stresses, as well as possible ways to obtain small proteins.

 
766-775 3378
Abstract

Cereals (Poaceae Barnh.) are the largest family of monocotyledonous flowering plants growing on all continents and constituting a significant part of Earth's many ecological communities. The Poaceae includes many important crops, such as rice, maize, wheat, barley, and rye. The qualitative and quantitative characteristics of cereal inflorescences are directly related to yield and are determined by the features of inflorescence development. This review considers modern concepts of the morphology, development and genetic mechanisms regulating the cereal inflorescence development. A common feature of cereal inflorescences is a spikelet, a reduced branch that bears florets with a similar structure and common scheme of development in all cereals. The length and the structure of the main axis, the presence and type of lateral branches cause a great variety of cereal inflorescences. Complex cereal inflorescences are formed from meristems of several types. The transition from the activity of one meristem to another is a multi-step process. The genes involved in the control of the cereal inflorescence development have been identified using mutants (mainly maize and rice) with altered inflorescence and floret morphology; most of these genes regulate the initiation and fate of meristems. The presence of some genetic mechanisms in cereals confirms the models previously discovered in dicotyledonous plants; on the other hand, there are cereal-specific developmental processes that are controlled by new modules of genetic regulation, in particular, associated with the formation of a branched inflorescence. An important aspect is the presence of quantitative variability of traits under the control of developmental genes, which is a prerequisite for the use of weak alleles contributing to the variability of plant growth and yield in breeding programs (for example, genes of the CLAVATA signaling pathway).

PLANT GENE POOL AND BREEDING

 
776-783 1145
Abstract

Statistics show negative forecasts of the demographic indicators of the Russian population including their size and health. The human habitat which has been deteriorating in recent decades causes cardinal changes in the assortment and variety of food and significantly contributes to the reduction of their biological value. The depletion of food products (FP) of vegetable and animal origin in vital mineral elements, vitamins and other physiologically active components represents a serious long-term threat to human health and the national security. Industrial methods of enriching FP have certain limitations: a narrow set of micronutrients, their interaction among themselves and accessibility for not all groups of the population. One way to reduce the negative consequences is through the introduction and breeding of new for Russia species and varieties of agricultural plants and organize a mass production of functional foods (FF) that contribute to the prevention and/or suspension of the development of dangerous diseases and slowing down the aging process. The solution of this multifaceted problem lies in changing the consumption structure of foods and their chemical composition conditioned by both the assortment of grown plant species and cultivars of food plants, as well as the composition and quality of soils, fertilizers and the conditions for crop cultivation. Taking into account the prevailing demographic situation in the Russian Federation, it is necessary to create a comprehensive national program for the allocation of new high-content sources of FF ingredients based on traditional and underutilized crops, cultivars and forms of cereal, vegetable and fruit crops and their inclusion in agricultural production as well as existing and newly created technological processes in food industry. The advantages of creating and developing a national system of the functional food in Russia will be: the improvement of public health and life expectancy, the reduction of the Federal Compulsory Medical Insurance Fund expenditures and the development of business structures involved in the production of the FF.

 
784-794 1191
Abstract

The sources were identified among collection samples characterized by highly pronounced economic and valuable features, which allows new geographically remote source material to be taken to the regional breeding practices. This research aims to assess the agronomic traits (duration of the growing period, lodging resistance and plant height, 1000-grain weight, grain weight and yield) in soft spring wheat varieties of different ecological and geographical origin. Estimation was carried out by a 9-point system of expression of the trait during the study, which allows identifying samples with the greatest expression of the trait in the years of study with respect to the average experience. 5439 samples have been studied over 28 years, with 1106 of them, over two years or more. The study was carried out according to the methods of VIR on plots of 2 m2. It was shown that the samples mainly had no correlation between the yield and the duration of the growing period, while the average dependence (г = 0.6) was revealed between the yield and the height of the plants. Varieties forming the intermediate (4.5-5 points) and above average (6-7) yield in a short growing period (69-85 days) were identified (Lutescens 675, Irkut-skaya 49, Simbirca, Hybrid F3 S-141, Hybrid F4, Hybrid F3 S-289 and Hybrid F4 S-2300 and Pamyati Vavenko-va). A high average score (8.6-9) at 1000 grains weight was shown for 16 varieties with variation from 37 g (N43 and IAO-9) to 56 g (Hofed 1). A high average score (8-9) in the evaluation of grain weight was shown for Pamyati Leont'eva, Ekada 70, Simbirtsit, Don Jose, Yong-Liang 4 and Long-Mai 11, which formed ears with an average weight from 0.96 to 2.30 g. A consistently high score (9) reflecting the yield was in the varieties Condestavel, PF 843025, Prilenskaya 19, Pamyati Leont'eva, Omskaya Krasa.

 
795-799 1284
Abstract

Strawberry (Fragaria x ananassa Duch.) varieties are susceptible to many fungal diseases. Identification of forms, carrying resistance genes, is an important stage in breeding programs leading to resistant varieties. The use of molecular markers allows to determine with high reliability the presence of the necessary genes in the genome and to identify promising forms. Some of the common strawberry's diseases, causing significant damage to strawberry plantations, are anthracnose (Colletotrichum acutatum Simmonds) and red stele root rot (Phytophthora fragariae var. fragariae Hickman). Dominant Rca2 gene is involved in monogenic resistance to C. acutatum pathogenicity group 2. Rpf1, Rpf2, Rpf3 genes are determined in monogenic resistance to red stele root rot. The purpose of this study was molecular genetic testing genotypes of genus Fragaria L. to identify carriers of Rca2 allele anthracnose resistance and Rpf1 allele red stele root rot resistance. The objects of study were the wild species of the genus Fragaria L. and strawberry varieties (Fragaria x ananassa Duch.) of different ecological and geographic origin. To assess allelic state Rca2 anthracnose resistance gene the dominant SCAR marker STS-Rca2_240 was used, was linked to the resistance gene Rca2 with a genetic distance of 2.8 cM. Rpf1 gene red stele root rot resistance was identified with the dominant SCAR marker R1A, was linked to the resistance gene Rpf1 with a genetic distance of 3.0 cM. The resistant allele of the marker STS-Rca2_240 was identified in the Laetitia variety (Rca2Rca2 or Rca2rca2 genotype), which allows us to recommend it as a promising source in breeding for anthracnose resistance. The other studied forms have homozygous recessive state of the marker STS-Rca2_240 (putative genotype rca2rca2). The resistant allele of the marker SCAR-R1A in the varieties and wild species of strawberry under study is absent, which presumably indicates their homozygous recessive genotype of Rpf1 gene (rpf1rpf1).

 
800-811 703
Abstract

A wide variety of application fields for flax seeds requires for breeders to develop new varieties with different characteristics, corresponding to the intended final product. The method of experimental mutagenesis is one of the ways to solve this problem. This method allows mutant lines with an array of morphometric and biochemical traits to be created from a single species and within a relatively short period of time. The article demonstrates that treatment of Linum humile Mill. seeds of the cultivars Iceberg and Solnech-ny with the new chemical mutagens DG-2, DG-6, DG-7, DG-9 (derivatives of dimethyl sulfate (DMS)) as well as with the mutagens DMS and EMS resulted in the production of mutant lines and accessions with altered morphometric and biochemical parameters. Seeds of the initial cultivars were treated with 0.5 and 0.05 % aqueous solutions of the above mentioned substances and planted in the field to raise M1, M2, and M3 generations. Ultimately, 27 types of mutations were identified and subdivided into five groups by morphometric characteristics. The fatty acid composition of seed oil for the isolated mutant specimens was studied: the content of palmitic, stearic, oleic, linoleic (w6) and lino-lenic (w3) acids, as well as the w6/w3 ratio. The statistical analysis showed significant distinctions between the mutant lines in the biochemical composition of the oil. A strong negative correlation between the content of linoleic and linolenic acids was demonstrated, as well as a positive relationship of average strength between the content of stearic and oleic acids for the both varieties. The mutant accessions obtained can be used as donor material for conducting breeding work on flax in various directions.

 
812-819 617
Abstract

Managing F1 heterosis is one of the major objectives in hybrid crop breeding programs. The classical theory considers the heterozygosity in F1 hybrids to be the main factor contributing to heterosis and therefore presumes a linear relationship between the value of genetic polymorphisms in parental lines and the heterotic response of their F1 offspring. Therefore, the genetic diversity information is viewed as a tool for selection of promising cross-combinations, but results published by different researchers are inconsistent. In this work, we studied the contributions of structural and nonstructural DNA polymorphisms to F1 heterosis manifestation. We used SSR and methyl-sensitive AFLP (MSAP with HpaII and MspI izoshisomers) protocols for obtaining specific patterns for heterotic and nonheterotic F1 hybrids of sweet pepper (Capsicum annuum L.) from a Belarusian breeding program. We found out that a certain portion of heterosis for yield-related traits might be explained by the polymorphism revealed by SSR analysis. According to our data, the total number of polymorphic SSR loci and the ratio of polymorphic and nonpolymorphic loci demonstrate a significant predictive value and can serve as additional prognostic criteria for the selection of promising cross-combinations. From the MSAP assay, we found a relationship between heterosis and the numbers of methylated and nonmethylated DNA loci for yield traits. Our results indicate that cross-hybridization may favor epiallelic modifications in F1 hybrids, presumably responsible for heterosis. Thus, epigenetic DNA variation may explain the absence of a linear relationship between the level of structural DNA divergence and F1 heterosis, as well as the manifestation of heterosis in crosses of related (genetically similar) accessions.

 
820-824 2039
Abstract

The article is devoted to the development of a technique for determining the content of amylose and amylopectin, effective for potato starch. Since potato starch is an important renewable raw material for a number of industries, it is important to have a throughput approach that allows potato starch samples to be tested quickly for the content of its constituent polysaccharides for potato breeding for starch properties and for starch industrial application. The developed technique includes elements of previously disjointed procedures for dissolution and spectrophotometric determination of amylose in starch, and combines the following advantages: 1) starch samples dissolve in an organic solvent (0.5 % solution of lithium bromide in dimethyl sulfoxide (DMS)); 2) measurement of light absorption is performed at two wavelengths, 550 and 510 nm, and 3) the technique is adapted for use with a plate spectrophotometer. This procedure allows starch polysaccharides to avoid to avoid hydrolysis during dissolution, allows the precise spectrophotometric determination of the concentration of amylose complex with iodine in solution, and opens the possibility of using this technique for throughput phenotyping. Applying a certain dissolution procedure, it is also possible to avoid the formation of gelled starch clots in solutions for spectrophotometry, which is important for the preparation of solutions containing amylose and amylopectin in the same proportions as in the original starch. The technique was tested on starch isolated from potato tubers varieties Lina, Velikan, Golubizna, Favorit of domestic selection. The technique developed can be used for phenotyping starch of an extended set of potato varieties (determining the content and composition of amylose in potato starch samples) to identify "trait-genotype” associations.

MAINSTREAM TECHNOLOGIES IN CELL BIOLOGY

 
825-836 730
Abstract

Primary cultures of human glioblastoma were obtained from the surgical material of patients K. (female, 61 years, Ds: relapse of glioblastoma) and Zh. (female, 60 years, Ds: relapse of glioblastoma). The effectiveness of a new therapeutic approach aimed at destroying the cancer cell community was evaluated on the primary cell lines of human glioblastoma culture by employing a new strategy of tumor-initiating stem cell synchronization and a domestic strategy of their eradication "3+1". The key elements of the strategy were the following indicator results: (1) evaluation of the presence of tumor-initiating stem cells in a population of cells from analyzed cultures by their ability to internalize double-stranded labeled DNA (TAMRA+ cells); (2) determination of the reference time points of the repair cycle of DNA interstrand cross-links induced by cross-linking cytostatic mitomycin C; (3) evaluation of cell cycle synchronization; (4) determination of the time (day after therapy initiation) when TAMRA+ cells were synchronously present in phase G1/S of the cell cycle, sensitive to the therapy; and (5) establishment of the TAMRA+ (tumor-initiating stem cells) eradication schedule. The cultures were treated with cross-linking cytostatic mitomycin C and a compositional DNA preparation. After the treatments, cell division slows down, and the cultures degrade. The K cell line completely degraded within 30 days of observation. The cell number of the Zh culture fell to nearly one-third of the starting value by day 15 of observation. On day 15, this indicator constituted 1/7.45 for mitomycin C and 1/10.28 for mitomycin C + DNA with reference to the control. The main target of the mitomycin C + DNA regimen was TAMRA+ tumor-initiating stem cells of the glioblastoma cell populations. The action of mitomycin C alone or in the combination with DNA demonstrated effective elimination of TAMRA+ tumor-initiating stem cells and the whole primary cultures of human glioblastomas.

 
837-844 1430
Abstract

The leaf epidermis of a monocotyledonous plant is a widely used model system for studying the differentiation of plant cells, as it contains readily observable specialized cells. The approach proposed in this paper uses a growing cereal leaf to study stress-induced dynamic changes in morphogenesis. In the process of formation, the linear leaf of wheat remains in the stationary growth phase for long. This fact permits us to observe a series of successive morphogenetic events recorded in the cellular structure of the mature leaf. In studying the cellular architecture of the wheat leaf epidermis, we obtained and processed confocal 3D images of wheat leaves stained with fluorescent dyes. This procedure allows an accurate morphometric description and determination of quantitative characteristics of the leaf epidermal pattern. Low temperatures are among the factors limiting the growing of crop plants in the temperate zone. In the present work, we show significant aberrations of stomatal morphogenesis in the epidermis of boot leaves of wheat varieties Saratovskaya 29 and Yanetskis Probat in response to cold stress. We found that nonfunctional stomata predominated in the zone of maximum manifestation of stress, whereas in the zones formed before and after the stress impact, the developmental anomalies come to the disturbance in the morphogenesis of subsidiary cells. In Saratovskaya 29, a significant amount of ectopic trichomes formed in rows predetermined to stoma formation. The proposed approach can provide standardized qualitative and quantitative data on stress-induced morphogenesis aberrations in wheat leaf epidermis. Subsequently, these data can be used for verification of computer models of leaf morphogenesis. Further study of the mechanisms of the effect of cold stress on morphogenesis will add to the search for additional opportunities to increase wheat yields in areas of risky agriculture.

SYSTEMS BIOLOGY

 
845-855 603
Abstract

The present work is devoted to the phenology of individual flowering and the construction of structure-dynamic models of this process on its basis. The results of the study of the flowering phenology of Campanula bononiensis, C. sarmatica and Platycodon grandiflorus are presented. The data obtained characterize both the phenological (time and duration of flowering, lifespan of individual flowers) and structural features (degree of branching of the inflorescence, length of floral axes, number of flowers, order of their blooming) that describe the flowering of a monocarpic shoot. Inflorescences of the species are elongated and multiflorous, of the compound type inherent for Campanulaceae, and characterized by a high variability of all structural features. Observation data were processed by standard statistical methods and used to construct stochastic computer models of flowering shoots, while omissions in data were restored by using the maximum likelihood method. Flowering patterns of the species, due to differences in phenological and structural features, have been revealed. It has been shown that flowering curves depend on the synchrony in the flowers blooming on the main (first-order) axis and lateral (second-order) axes. C. bononiensis has one asymmetrical peak with a broadening on the left, achieved with the simultaneous blooming of flowers in the upper and lower parts of the main axis and on lateral axes in the middle part of the inflorescence, where the first-order flowers have already finished blooming (they provided the broadening). Flowering curves for C. sarmatica and P grandiflorus are bimodal, with the first peak being due to the flowers blooming on the main axis and the second one on lateral axes. The constructed models reproduce the patterns of individual flowering well, with natural variability, and can be used to simulate the flowering of a group of individuals (population), for example, in landscape design. In combination with visualization tools, they can be used for augmenting plant phenotyping datasets with rendered images of synthetic plants for the purpose of training neural networks in this field.

 
856-863 1098
Abstract

Opisthorchiasis is a dangerous parasitic disease caused by trematodes in the family Opisthorchiidae. One of the causes of this infection is the species Opisthorchis felineus, which is common in the Russian Federation and Western Europe. The disease has a large number of complications and relatively few effective treatments, so nowadays it is relevant to look for new drugs for the treatment of opisthorchiasis, with the maximum antiparasitic and minimal side effect. In this work, a potentially anthelmintic effect of the methanol extract of the golden chanterelle mushroom (Cantharellus cibarius) was investigated. In in vitro experiments, the significantly reduced mobility and survival rates of juvenile O. felineus specimens with increasing concentrations (10-1000 pg/ml) of the C. cibarius extract were shown. In in vivo studies, administration of the C. cibarius extract on the first day after parasitic infection of inbred C57BL/6 mice resulted in a decrease of the number of helminths in the bile ducts of the liver, evaluated 6 weeks after infection. In another series of experiments, administration of the C. cibarius extract for 7 days to mice infected with O. felineus for five weeks had no anthelmintic effect. In both cases, the state of the infected hosts, evaluated by a number of physiological and biochemical parameters (relative weight of organs, blood indices), did not deteriorate, indicating that there was no adverse effect of the C. cibarius extract. The results obtained suggest that the C. cibarius extract might have anthelmintic properties if applied as parasite larvae excyst.

MEDICAL GENETICS

865-872 873
Abstract

Osteoarthritis (OA) is a common multifactorial joint disease. Undifferentiated connective tissue dysplasia (uCTD) is a genetically determined lesion of the connective tissue structures, including joints, and it can be one of the factors predisposing to development of OA. Solving the problem of comorbidity of OA and uCTD signs will contribute to the early diagnosis and prophylactics of OA. Aggrecan is one of the major structural components of cartilage and it provides the ability to resist compressive loads throughout life. We examined 316 women (mean age 50.5 ± 4.77) for signs of uCTD and OA. A study of the aggrecan gene (ACAN) VNTR polymorphism, which is represented by a variable number of 57 nucleotide repeats, was performed. We searched for associations between the VNTR locus and OA in general and with an account of the localization of the pathological process, as well as with the presence of uCTD signs. Twelve allelic variants and 24 genotypes of the VNTR polymorphism of the aggrecan gene (ACAN) were identified, the most frequent variants were alleles with 27, 28 and 26 repeats. A significance of allele *27 (х2 = 6.297, p = 0.012, odds ratio (OR) = 1.50; 95 % confidence interval (CI) 1.09-2.05) in the development of OA in general, knee OA (х2 = 4.613, p = 0.031, OR = 1.52; 95 % CI 1.04-2.23), and multiple OA (х2 = 4.181, p = 0.04, OR = 1.68; 95 % CI 1.02-2.78) was revealed. Homozygous genotype *27*27 was associated with OA (х2 = 3.921, р = 0.047, OR = 1.72; 95 % CI 1-2.96), and OA with uCTD signs in women (х2 = 5.415, p = 0.019, OR = 2.34; 95 % CI 1.13-4.83).

873-877 696
Abstract

Kidney cancer is a heterogeneous group of malignant tumors, the vast majority of which are renal cell carcinomas (RCC) of various morphological types, of which the most common is the clear cell renal cell carcinoma (ccRCC). Particular attention in the carcinogenesis of the ccRCC is given to a number of tumor suppressor genes located on the short arm of the third chromosome. One of these genes, which are inactivated in the case of ccRCC is the PBRM1 gene encoding the PBAF SWI/SNF subunit of the chromatin remodeling complex, BAF180. The PBRM1 gene is located on the short arm of the third chromosome in the 3p21 region near the von Hippel-Lindau gene (VHL), the mutation in which is the main event in the occurrence of ccRCC. The aim of our investigation is identification of changes in the nucleotide sequence of the PBRM1 tumor suppressor gene in patients with ccRCC. 210 pairs of DNA samples isolated from ccRCC tissue were studied. Analysis of changes in the nucleotide sequence of DNA was carried out by HRM analysis and direct sequencing. In the PBRM1 gene, two somatic mutations were found (c.233G>A (p.D45N) in exon 2, c.1675-1676delTC in exon 15) which were not described previously, and one known polymorphic variant rs17264436 (in exon 23). The frequency of detected mutations was 0.95 % of cases. Analysis of the allelic association for the polymorphic locus rs17264436 showed a statistically significant increase in the risk of developing advanced kidney cancer in carriers of allele rs17264436*A, which can be used in the development of prognostic marker panels. Perhaps the low frequency of mutations in the samples we studied is due to the fact that the inactivation of the PBRM1 gene takes place in other ways, and may also be due to the ethno-specificity of the studied group of patients.

ANIMAL GENETICS

 
878-886 1137
Abstract

The light of the visible spectrum (with wavelengths of 380-780 nm) is one of the fundamental abiotic factors to which organisms have been adapting since the start of biological evolution on the Earth. Numerous literature sources establish a connection between the duration of exposure to daylight, carcinogenesis and longevity, convincingly showing a significant reduction in the incidence of cancer in blind people, as well as in animal models. On the other hand, the stimulating nature of the effect of continuous illumination on reproductive function was noted, in particular, the effects of increasing the fecundity of females of various species are known. Increase in motor activity and, as a result, in metabolic rate and thermogenesis during permanent exposure to light also reduces the body's energy reserves and lifespan. In principle, in the context of aging, not only the exposure time, but also the age at the onset of exposure to constant illumination matter, the reverse effects are valid for the maintenance of experimental animals in the constant darkness. Over the long period of the evolution of light signal transduction systems, many mechanisms have emerged that allow to form an adequate response of the organism to illumination, modulating the highly conservative signaling cascades, including those associated with aging and lifespan (FOXO, SIRT1, NF-kB, mTOR/S6k, PPARa, etc). In this review, we consider the relationship between lifespan, photoregimens, and also the expression of the genes encoding the phototransduction cascade and the circadian oscillator elements of animal cells. In the present paper, basic transducers of light and other signals, such as the family of TRP receptors, G proteins, phospholipase C, and others, are considered in the context of aging and longevity. A relationship between the mechanisms of thermoreception, the temperature synchronization of the circadian oscillator and the life span is established in the review. Analysis of experimental data obtained from the Drosophila melano-gaster model allowed us to formulate the hypothesis of age-dependent photoresistance - a gradual decrease in the expression of genes associated with phototransduction and circadian oscillators, leading to deterioration in the ability to adapt to the photoregimen and to the increase in the rate of aging.

 
887-894 626
Abstract

Mitochondrial DNA sequences integrated into chromosomes are a promising object for designing genetic markers for studies of phylogenesis and genomic instability. Mitochondrial genomes of D. virilis and other Drosophila species of the virilis group contain (AT)n microsatellites in the spacer region between the atp6 and cox3 genes, and this microsatellite sequence is one of the hallmarks of the virilis group. The nuclear genome of D. virilis contains many extended fragments of mitochondrial DNA, which in total are several times longer than the mitochondrial genome. These nuclear sequences of mitochondrial origin contain all types of mitochondrial sequences, including mitochondrial genes and the aforementioned microsatellite sequence. The presence of the (AT)n microsatellite allows insertion of retrotransposon Tv1, which can transpose into the (AT)n microsatellite in a site-specific manner. The Tv1 insertion into (AT)n, close to the atp6 or cox3 pseudogenes produces a unique sequence. This sequence is formed by retrotransposon Tv1 and pseudogenes atp6 or cox3. This unique sequence can be detected in the genome by a PCR-based method. We applied this method to the detection and analysis of the nucleotide variability of the pseudogenes atp6 and cox3 associated with Tv1 insertions in a D. virilis cell culture and in the genomes of four Drosophila species of the virilis group: D. virilis, D. montana, D. borealis, and D. lacicola. We discovered new events of mitochondrial sequence transfer to the nucleus in the transplanted cell culture of D. virilis, and new Tv1 insertions, having emerged during the passage of this cell line were detected in the genome of the D. virilis transplanted cell culture. We found atp6 and cox3 pseudogenes associated with insertions of retrotransposon Tv1 in the nuclear genomes of four Drosophila species from the virilis group. These chimeric sequences proved to be species-specific. The age of the Tv1 insertion into the atp6 and cox3 pseudogenes is estimated at 1.50 Ma for D. virilis, 1.31 Ma for D. lacicola, and 1.56 Ma for D. borealis. A specific situation was revealed for D. montana, in which Tv1 insertions with nearly identical 5' and 3' long terminal repeats (LTRs) were present in accessions of flies from Europe and Asia. The age of this insertion was about 300 thousand years, and the insertion was absent from the D. montana fly line from North America.

POPULATION GENETICS

 
895-904 1857
Abstract

Applying quasigenetic markers - non-biological traits which are nevertheless inherited in generations - is one of the research fields within human population genetics. For the West European, East European, and Caucasus populations, surnames are typical quasigenetic markers. For Central Asian populations, particularly Kazakh, the clan affiliation serves as a good marker: a set of papers demonstrated that many clans include mainly persons which biologically descent from a recent common ancestor. In this study, we analyzed a large (~4.2 million persons) dataset on quasigenetic markers - the geographic distribution of 50 Kazakh clans at the beginning of the 20th century, and compared the dataset with the direct data of the Y-chro-mosomal diversity in modern Kazakh populations. The analysis included three steps: the isonymy method, which is standard for quasigenetic markers, comparing frequencies of quasigenetic markers, and comparing the quasigenetic and genetic datasets. We constructed 50 maps of frequency of the distribution of each clan and revealed that these maps correlate with the maps of genetic distances. The Mantel test also demonstrated a significant correlation between geographic and quasigenetic distances (г = 0.60; p < 0.05). The analysis of inter-population variability revealed the largest diversity between geographic territories corresponding to the social-territorial groups of the Kazakh Khanate (zhuzes) rather than to other historical groups that existed on the territory of Kazakhstan in preceding and modern epochs. The same is evidenced by the principal components and multidimensional scaling plots, which grouped geographic populations into three clusters corresponding to three zhuzes. This indicates that the final structuring of the Kazakh gene pool might have occurred during the Kazakh Khanate period.



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