[Hepatitis virus genotype structure in patients with chronic hepatitis C].

Aim: Studies of hepatitis C virus (HCV) genotype and subtype structure in patients with chronic hepatitis C in 3 regions of the Central federal district of Russia.

Materials And Methods: Hepatitis C virus genotype and subtype structure was determined in patients with chronic HCV infection in Moscow (1993 - 1995 and 2005), Moscow region (2008) and Vladimir region (1993 -1995, 2005-2007). HCV genotype was determined by using A.

[Current view on tetrapod's origin and diversification].

For the last few decades a wealth of evidence have been obtained (including new fossils, and new nucleotide sequences) which provide a way of revising the current evolutionary theories. The primary structures of a number of orthological regions from a variety of genomes have been evaluated. Full sized genomic sequences for some organisms, have been detected.

[Specific organization of ribosomal DNA arrays in Squamata].

A first report on structural organization of ribosomal DNA arrays in some members of the order Squamata is presented. The data obtained point to unusually small (for vertebrates) size of the rDNA repetitive unit (approximately, 10 to 15 kb) in the lizard species examined. Analysis of BAC library of Uta stansburiana (Iguania) showed that haploid genome of this lizard contained a single cluster, consisting of about ten rDNA repeats.

[Evolutionary divergence of the ribosomal internal transcribed spacer 2 (ITS2) in lizards].

During the pre-rRNA cleavage pathway, the excision of ITS2, a eukaryotic specific insertion, remains the most elusive processing step, even in yeast. Comparison of the ITS2 sequences in different organisms permits to reveal conservative, presumably functionally important elements as well as obtain new information about ITS2 divergence in evolution. We have cloned and sequenced the ITS2 of three lizard species, Agama caucasia (Agamidae), Darevskia armeniaca and Lacerta strigata (Lacertidae) and detected in them a set of specific and conservative structural elements employing secondary structure consensus for vertebrate ITS2.

[Detection of intragenomic polymorphism in the LR2 region of human intergenic ribosomal spacer].

It is a common point of view today that tandem ribosomal genes are subject to concerted evolution, a process that promotes homogeneity among the many copies through the mechanisms of unequal homologous exchange and gene conversion. These mechanisms can lead to opposite results: they can correct and eliminate new variants and they also can promote the spread of new gene variants throughout individual gene clusters among homologous and non homologous chromosomes. A number of experiments performed to decide which of these mechanisms is more important have yielded contradictory answers to this question.