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V A Gvozdev

Publications and source records attributed to V A Gvozdev.

At least 73 records · Page 4Linked to original sources
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[Role of double-stranded RNA in eukaryotic gene silencing].

Data on RNA interference, that is, posttranscriptional gene silencing by homologous double-stranded (ds) RNA, are reviewed. Gene silencing caused by exogenous dsRNA in artificial systems and observed in transgenic organisms carrying additional gene copies is considered. Data are summarized on the mechanism that arose during evolution of the Drosophila melanogaster genome to suppress repetitive genes with the use of dsRNA and thereby to prevent male sterility. The role of dsRNA in inhibiting expression and transposition of mobile elements is discussed on the basis of authors own and published findings.

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[The phenomenon of RNA interference and development of organism].

RNA interference consists in specific mRNA degradation in response to introduction of a double-stranded RNA, homologous in nucleotide sequence. RNA interference was found in eukaryotes and is used in genomics as a powerful method to determine the functions of genes with known nucleotide sequences. RNA interference is considered as a tool of protection against viruses and harmful consequences of mobile elements' transposals. The involvement of the components of RNA interference is considered in spermatogenesis of Drosophila melanogaster and regulation of the expression of genes in Caenorhabditis elegans responsible for temporal patterns of development. The role of RNQA interference in stem cell formation and functioning is also considered.

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A new type of organization of the genetic material in eukaryotes.

An investigation of the properties of a number of genes of Drosophila, obtained by cloning recombinant DNAs, led to the detection of a new type of organization of genetic material. It was found that a number of actively working structural genes of Drosophila are represented by a large number of copies, scattered over its chromosomes. Their localization in the chromosomes is variable, although they are always detected in regions of intercalary heterochromatin. The latter evidently is a site of accumulation of various multiple genes.

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[RNA binding proteins in the RNA interference phenomenon].

The ability of short RNAs (21-27 nucleotides) to silence genes containing homologous nucleotide sequences is related to RNA silencing. The pathways of short RNAs (siRNA and microRNA) biogenesis from their precursors, double stranded and hairpin RNAs respectively, are briefly reviewed. The functioning of specific RNA binding domains found for the first time in the proteins operating in RNA interference (RNAi) is considered. The interactions of these domains with the earlier well known RNA binding modules in RNAi proteins are described.

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PubMedDate not supplied

[Genome organization in eukaryotes].

The review discussed problems of genome organization in the chromosomes of eukaryotes based on the data of genetical and molecular-biological studies. Particular attention is paid to the peculiarities of organization of genetic material in Drosophila. The main (euchromatic) part of the genome is considered as the totality of separate functional units (chromomere, gene loci), which have in the average a higher excess of DNA compared to the sized of the structural gene. The possible ways of internal organization of these units and the role of different types of DNA sequences in their function are discussed. The features of organization and function of the heterochromatic regions of chromosomes consisting of simple sequences of satellite DNA and tandemly repeated genes (polygenes), that code for general cellular functions (similar to the ribosomal genes) are considered. The instability of the number and even the sites of localization of polygenes in the chromosome, which can be determined by the peculiarities of their functions during differentiation of somatic cells is notes.

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PubMedDate not supplied

[Variability of the heterochromatic regions of the eukaryotic genome in connection with their possible biological role (based on the example of Drosophila melanogaster)].

Heterochromatin in the genomes of higher eukaryotes carrying repeated DNA sequences comprises up to 30-50% of the total DNA content. Repeated elements (satellites, retrotransposons, and tandemly repeated genes) in heterochromatin of D. melanogaster are considered in respect of their amplification resulting in pronounced biological effects. These elements were coined as "egoistic DNA" whose amplification may be restricted as a result of unknown types of interactions with the host genome. Correlations of the extent of amplification of heterochromatin elements with the fitness of individuals, reproductivity, and capability to transmit to the progeny a chromosome carrying the amplified heterochromatic region are discussed. The possible dependence of the genotypic structure and the fate of population in successive generations on the events of amplification of repeated heterochromatic elements in parental genomes is accentuated. In other words, "intragenomic population processes" driven by the amplification of several types of repeats ("egoistic DNA") must be taken into account when considering the dynamics of biological events in the course of propagation of individuals in a population.

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