Vol 52, No 12 (2016)

LINE-1 retrotransposon is the most common mobile genetic element in the genomes of various mammals, including humans. Its genes are represented by the greatest number of copies. For a long time, it has been considered that the presence of LINE-1 in genome reflects the limited ability of cells to eliminate it, and the retrotransposon activity is negative owing to the insertional mutagenesis. In recent years, the increased expression of LINE-1 retrotransposon and the activity of their encoded proteins observed in mammalian cells at different stages of development and, first of all, in early embryogenesis have been discussed in the literature. Is early embryogenesis the stage of development when the organism is more susceptible to the activity of retrotransposons, or does LINE-1 play some positive role in early embryonic development? This review is aimed at classifying the available data on the epigenetic regulation and the role of LINE-1 retrotransposon in embryogenesis of mammals. The link between the mechanisms of regulation of LINE-1 expression and the waves of epigenetic reprogramming is tracked in germ cells, during fertilization, and in blastocyst, as well as during the differentiation of embryonic and extraembryonic tissues.

A catalog of winter wheat varieties bred in Russia and Ukraine for alpha-amylase isozymes is presented. Among them, 11 phenotypic classes were found. It was established that the observed differences in the frequency of specific phenotypes for alpha-amylase in the culture of winter wheat depended on the geographical origin. The percentage of the most widespread cultural phenotype, designated as AbCde, decreased from the south (45°–46° N) to the north (49°–50° N) by 31.0%. At the same time, the frequency of the abCde variant increased by 25.0%. The distribution of the Abcde phenotype changed significantly from 20.7% in the west (30o36′ E) to 0% in the east (40o18′ E). The observed territorial dynamics for alpha-amylase isoenzymes may indicate the adaptive value of the identified phenotypes of common winter wheat for the weather and climatic conditions of the region of their origin.

Siberian stone pine, Pinus sibirica Du Tour is one of the most economically and environmentally important forest-forming species of conifers in Russia. To study these forests a large number of highly polymorphic molecular genetic markers, such as microsatellite loci, are required. Prior to the new high-throughput next generation sequencing (NGS) methods, discovery of microsatellite loci and development of micro-satellite markers were very time consuming and laborious. The recently developed draft assembly of the Siberian stone pine genome, sequenced using the NGS methods, allowed us to identify a large number of microsatellite loci in the Siberian stone pine genome and to develop species-specific PCR primers for amplification and genotyping of 70 microsatellite loci. The primers were designed using contigs containing short simple sequence tandem repeats from the Siberian stone pine whole genome draft assembly. Based on the testing of primers for 70 microsatellite loci with tri-, tetra- or pentanucleotide repeats, 18 most promising, reliable and polymorphic loci were selected that can be used further as molecular genetic markers in population genetic studies of Siberian stone pine.

A comprehensive population and medical-genetic study was carried out in ten districts and two cities in the Karachay-Cherkess Republic (Russia). As a result, 57 patients with phenylketonuria were revealed. PAH gene genotypes for 40 probands and their diseased and healthy relatives were determined. The mutation spectrum of the PAH gene in the Karachay-Cherkess Republic was investigated. The major mutation in this region is R261X with allelic frequency of 68.4%. We elaborated a convenient system for detection of six PAH gene mutations common in the Karachay-Cherkess Republic, with the total information content of the system being 89.9%. As a result of processing the clinical data, association of the diet and phenylalanine levels in the blood was verified. Genophenotypic analysis confirms the association of the residual activity of phenylalanine hydroxylase and the severity of the disease. It is shown that common mutation R261X is severe and that patients who are homozygous for this mutation have classical phenylketonuria (PKU).

NBS-profiling was used to study NBS-LRR resistance genes polymorphism in 32 Russian and foreign apple (M. domestica) varieties and nine Antonovka landraces. NBS-LRR resistance genes variability in the studied apple varieties was rather low. While in Antonovka landraces specific NBS-patterns were revealed, which may indicate the presence of a number of unique resistance genes. The results confirm that Antonovka landraces belong to M. domestica and Yakutskaya apple belongs to the section Gymnomeles.