[Topological Conflicts in Phylogenetic Analysis of Different Regions of the Sable (Martes zibellina L.) Mitochondrial Genome].

Phylogenetic analysis of different regions of the mitochondrial genome of the sable showed the presence of several topologies of phylogenetic trees, but the most statistically significant topology is A-BC, which was obtained as a result of the analysis of the mitochondrial genome as a whole, as well as of the individual CO1, ND4, and ND5 genes. Analysis of the intergroup divergence of the mtDNA haplotypes (Dxy) indicated that the maximum Dxy values between A and BC groups were accompanied by minimum differences between B and C groups only for six genes showing the A-BC topology (12S rRNA; CO1, CO2, ND4, ND5, and CYTB). It is assumed that the topological conflicts observed in the analysis of individual sable mtDNA genes are associated with the uneven distribution of mutations along the mitochondrial genome and the mitochondrial tree. This may be due to random causes, as well as the nonuniform effect of selection.

[Phylogenetic relationships among Asiatic salamanders of the genus Salamandrella based on variability of nuclear genes].

Based on sequence variation of three nuclear genome genes (BDNF, POMC, and RAG1), the phylogenetic relationships among Asiatic salamanders of the genus Salamandrella, Siberian salamander (S. keyserlingii) and Schrenk salamander (S. schrenkii), were examined. Both species demonstrated high levels of heterozygosity determined by intraspecific polymorphism. Fixed interspecific differences were revealed at one nucleotide position of the RAG1 gene, and thus the level of interspecific divergence over the three genes constituted only 0.04%. Analysis of the RAG1 polymorphism across the whole range of S. keyserlingii showed that only one gene variant, encoding for modified RAG1 recombinase, had the highest distribution to the north of the Amur region (west and northeast of Siberia). It is possible that the changes in the RAG1 gene in Siberian salamander are of an adaptive nature. However, cases of interspecific hybridization were identified in Jewish autonomous oblast (JAO), which contains one of the range borders between the two Salamandrella species.

[Mitochondrial Genome Variability in the Wolverine (Gulo gulo)].

The nucleotide sequence of an extended mitochondrial genome segment (11473 base pairs in size) was determined in the wolverine (Gulo gulo) from Magadan oblast. Phylogenetic and statistical analyses of mitochondrial DNA (mtDNA) sequences of mustelids showed that the separation of the Gulo phylogenetic branch occurred at the Miocene--early Pliocene (about 5.6 million years ago (MYA)), while the formation of the species G. gulo took place in the Middle Pleistocene (181 and 234 thousand years ago (KYA), according to the results of molecular dating based on the variability of the extended mtDNA segment and the mitochondrial cytochrome b gene, respectively). The molecular data were in agreement with the fossil records for wolverines.

[Episodes of adaptive evolution of mitochondrial genome in Asiatic salamanders (Amphibia, Caudata, Hynobiidae)].

To elucidate the effect of natural selection on the evolution of mitochondrial DNA (mtDNA) in Asiatic salamanders of the family Hynobiidae, nucleotide sequences of 12 protein-coding genes were analyzed. Using a mixed effects model of evolution, it was found that, in spite of the pronounced effect of negative selection on the mtDNA evolution in Hynobiidae (which is typical for the animals in general), two phylogenetic clusters, the West Asian one, represented by the genera Ranodon and Paradactylodon, and North Eurasian one, represented by the genus Salamandrella, were formed under the influence of episodic positive selection. Analysis of protein sequences encoded by the mitochondrial genome also supported the influence of positive selection on the evolution of Hynobiidae at some stages of their cladogenesis. It is suggested that the signatures of adaptive evolution detected in the mtDNA of Hynobiidae were determined by the complex and long-lasting history of their formation, accompanied by adaptation to the changing environment.

[Peculiarities of phosphoglycerate kinase-1 pseudogene evolution in Schrenck salamander (Salamandrella schrenckii Strauch, 1870)].

Processed copies of genes generally evolve in neutral mode as pseudogenes, however, some of them might be important sources of new functional genes. The psiPGK1 pseudogene has been discovered in Schrenck salamander (Salamandrella schrenckii, Amphibia, Caudata, Hynobiidae) via polymerase chain reaction used to amplify the phosphoglycerate kinase 1 gene (PGK1). This pseudogene is an intronless copy of PGK1 gene absent of exon 6. Analysis of psiPGK1 pseudogene polymorphism has demonstrated that it lacks mutations, which results in shifts in the stop codons and reading frames, as well as that the interspecies variation of this pseudogene was inconsistent with the neutral model of evolution. In addition, the pattern of phylogeographic differentiation of the psiPGK1 variants mainly coincides with that observed in mitochondrial DNA. These observations allow it to be suggested that the psiPGK1 pseudogene is a new functional gene in the Schrenck salamander.

[Population structure of Volga Tatars inferred from the mitochondrial DNA diversity data].

The data on mitochondrial DNA (mtDNA) variation in two populations of Volga Tatars, representing the population of Buinsk and Aznakaevo districts of the Republic of Tatarstan are presented. Comparative analysis of the data on mtDNA variation in the populations of Eastern Europe showed that Volga Tatars were characterized by low interpopulation differentiation (F(ST) = 0.33%), while the level of interethnic differentiation in Eastern Europe is 1.8%. Genetic similarity of Tatars from the eastern regions of Tatarstan to Bashkirs, as well as of Tatars from western regions to Chuvashes, with whom they share territorial borders, was revealed. Positive correlation between population genetic structure in Eastern Europe and linguistic affiliation of the ethnic groups studied was observed.

[Autoimmune response in HIV-infected patients is directed against CD4 domain 4].

Phage display epitope library technology and a novel computer algorithm have been used for the localization of CD4 epitopes specific for monoclonal antibody (mAb) T6 and autoimmune antibodies found in an HIV infected patient. Both predicted epitope clusters have been shown to overlap and to be localized within the domain 4 of CD4. They included Cys303, Glu304, Glu330, and Lys331 amino acids. Few amino acids predicted by the algorithm as the epitope residues and two residues that did not relate to the epitope were sequentially substituted for Ala. Further analysis of the mutated forms of sCD4 expressed in 293T cells transfected with the corresponding DNAs, supported the predicted localization of the mAb T6 epitope. The results demonstrate that the autoimmune response in HIV-infected patients is directed against domain D4 of sCD4.

[Distribution of the male lineages of Genghis Khan's descendants in northern Eurasian populations].

Data on the variation of 12 microsatellite loci of Y-chromosome haplogroup C3 were used to screen lineages included in the cluster of Genghis Khan's descendants in 18 northern Eurasian populations (Altaian Kazakhs, Altaians-Kizhi, Teleuts, Khakassians, Shorians, Tyvans, Todjins, Tofalars, Sojots, Buryats, Khamnigans, Evenks, Mongols, Kalmyks, Tajiks, Kurds, Persians, and Russians; the total sample size was 1437 people). The highest frequency of haplotypes from the cluster of the Genghis Khan's descendants was found in Mongols (34.8%). In Russia, this cluster was found in Altaian Kazakhs (8.3%), Altaians (3.4%), Buryats (2.3%), Tyvans (1.9%), and Kalmyks (1.7%).

[Epitope mapping of antigenic determinants of hepatitis C virus proteins by phage display].

Study of individual hepatitis C (HCV) proteins could help to find a molecular structure and conformation, localization of antigenic and immunogenic determinants, to reveal of protective epitopes. It is necessary for practical medicine - development of diagnostic test-systems, vaccines and therapeutics. Linear and conformation dependent epitopes of HCV proteins was localized in this work and immunogenic properties of phage displayed peptides screened on monoclonal antibodies to HCV proteins have been investigated. Eleven epitopes of four HCV proteins have been studied. Three epitopes was found as linear, two epitopes were dependent on secondary structure of proteins and one epitope was dependent on tertiary structure of NS3 protein. Aminoacid sequences of other determinants have been determined and the distinct localization of these determinants will be continued after discovering of tertiary structure of HCV proteins. It was shown, that phage mimotope 3f4 is immunogenic and could induce specific hu- moral immune response to NS5A HCV protein. The data obtained could be useful for improving of HCV diagnostic test-systems, studying of amino acid substitutions and its influence on antigenic properties of the HCV proteins. The results could help to study an immune response in patients infected with different genotypes of HCV. Phage displayed peptides mimicking the antigenic epitopes of HCV proteins could be applied to development of HCV vaccine.

[Anti-CD4 autoimmunity in HIV-infected persons in Russia].

The frequency of anti-CD4 antibodies was determined in the sera or plasma derived from the patients infected with HIV-1 belonging to different genetic subgroups. The anti-CD4-antibodies in a dilution of > or = 1:1000 were found in 14% of the patients infected with the gagA/envA virus characteristic for injectable drug users in East Europe. The frequency of autoimmune antibodies among the HIV-infected patients with envB virus was substantially less (4.4%). Competitive ELISA using monoclonal antibodies to different CD4 domains demonstrated that irrespective of the viral genotype, the autoimmune epitope is located within the D4 or D3/D4 domains of CD4 receptor.

[Mitochondrial DNA variation in two Russian populations from Novgorod oblast]. / Izmenchivost' mitokhondrial'noi DNK v dvukh populiatsiiakh russkogo naseleniia novogorodskoi oblasti.

Mitochondrial DNA (mtDNA) polymorphism was examined in two Russian populations of Novgorod oblast, from the city of Velikii Novgorod (n = 81), and the settlement of Volot (n = 79). This analysis showed that the mitochondrial gene pool of Russians examined was represented by the mtDNA types belonging to 20 haplogroups and subhaplogroups distributed predominantly among the European populations. Haplogroups typical of the indigenous populations of Asia were found in the population sample from Velikii Novgorod with the average frequency of 3.7% (haplogroups A, Z, and D5), and with the frequency of 6.3% (haplogroups Z, D, and M*) in the Volot population. It was demonstrated that the frequency of the mitochondrial lineages combination, D5, Z, U5b-16144, and U8, typical of the Finnish-speaking populations of Northeastern Europe, was somewhat higher in the urban population (7.4%) compared to rural one (3.8%). The problem of genetic differentiation of Russians from Eastern Europe inferred from mtDNA data, is discussed.

Hierarchical structure of donor splice site sequence multitude.

An analysis of donor splice site sequence (dsss) multitude was carried out. A special method was developed to study the multitude properties. The multitude of dsss was arranged as a hierarchical tree where the "root" consists of a small group of "ancestors", VAGgtVAG (gt stands in the beginning of intron, V=C,A,G). Every ancestor has its own clan of "descendants" which represent point mutants of it. The latter are split into "progenies". The first progeny looks like point mutants of the ancestors, the second as one-point mutants of sequences of the first progeny, and so forth. This picture looks like a hierarchical phylogenetic tree. The most striking property of the multitude is the successive monotonic decrease in occurrences of the sequences from one progeny to another. It is shown that such results may be modeled by a virtual mutational process.

Diversity of mitochondrial DNA lineages in South Siberia.

To investigate the origin and evolution of aboriginal populations of South Siberia, a comprehensive mitochondrial DNA (mtDNA) analysis (HVR1 sequencing combined with RFLP typing) of 480 individuals, representing seven Altaic-speaking populations (Altaians, Khakassians, Buryats, Sojots, Tuvinians, Todjins and Tofalars), was performed. Additionally, HVR2 sequence information was obtained for 110 Altaians, providing, in particular, some novel details of the East Asian mtDNA phylogeny. The total sample revealed 81% East Asian (M*, M7, M8, M9, M10, C, D, G, Z, A, B, F, N9a, Y) and 17% West Eurasian (H, U, J, T, I, N1a, X) matrilineal genetic contribution, but with regional differences within South Siberia. The highest influx of West Eurasian mtDNAs was observed in populations from the East Sayan and Altai regions (from 12.5% to 34.5%), whereas in populations from the Baikal region this contribution was markedly lower (less than 10%). The considerable substructure within South Siberian haplogroups B, F, and G, together with the high degree of haplogroup C and D diversity revealed there, allows us to conclude that South Siberians carry the genetic imprint of early-colonization phase of Eurasia. Statistical analyses revealed that South Siberian populations contain high levels of mtDNA diversity and high heterogeneity of mtDNA sequences among populations (Fst = 5.05%) that might be due to geography but not due to language and anthropological features.

[Mitochondrial DNA variation in Russian populations of Stavropol krai, Orel and Saratov oblasts]. / Izmenchivost' mitokhondrial'noi DNK v populiatsiiakh russkogo naseleniia Stavropol'skogo kraia, Orlovskoi i Saratovskoi oblastei.

Mitochondrial DNA (mtDNA) polymorphism was examined in three Russian populations from the European part of Russia (Stavropol krai, Orel oblast, and Saratov oblast). This analysis showed that mitochondrial gene pool of Russians was represented by the mtDNA types belonging to haplogroups H, V, HV*, J, T, U, K, I, W, and X. A mongoloid admixture (1.5%) was revealed in the form of mtDNA types of macrohaplogroup M. Comparative analysis of the mtDNA haplogroup frequency distribution patterns in six Russian populations from the European part of Russia indicated the absence of substantial genetic differences between them. However, in Russian populations from the southern and central regions the frequency of haplogroup V (average frequency 8%) was higher than in the populations from more northern regions. Based on the data on mtDNA HVS1 sequence variation, it was shown that the diversity of haplogroup V in Russians (h = 0.72) corresponded to the highest h values observed in Europe. The reasons for genetic differentiation of the Russian population (historical, ecological, and adaptive) are discussed.

[Molecular genetic differentiation of ethnic populations in Southern and Eastern Siberia based on mitochondrial DNA polymorphism]. / Molekuliarno-geneticheskaia differentsiatsiia étnicheskikh grupp Iuzhnoi i Vostochnoi Sibiri po dannym o polimorfizme mitokhondrial'noi DNK.

Using the data on mitochondrial DNA (mtDNA) polymorphism, genetic structures of the ethnic groups inhabiting South and East Siberia, including Altaians, Buryats, Tuvinians, Todjins, Tofalars, Yakuts, and Evenks were described. Mitochondrial gene pools of the populations examined were characterized by different ratios between Mongoloid (M*, C, D, E/G, G, A, B, and F) and Caucasoid (H, HV, I, J, K, T, U, and X) mtDNA lineages. All the populations studied carried a marked Mongoloid component, maximum frequency of which was observed in Evenks (92.4%) and Buryats (90.1%). Maximum frequencies of Caucasoid mtDNA lineages were detected in Tofalars (20.7%) and Yakuts (14.5%). Statistically significant interpopulation differences regarding the frequencies of mtDNA haplogroups were observed between all populations examined, excluding the pairs of Evenks-Yakuts, Evenks-Tuvinians, and Tuvinians-Todjins. Differentiation of the ethnic groups inhabiting South and East Siberia, as well as Central and Middle Asia, is discussed based on genetic, linguistic, and anthropological data.

[Mitochondrial DNA polymorphism in populations of the Caspian region and southeastern Europe]. / Polimorfizm mitokhondrial'noi DNK v populiatsiiakh Kaspiiskogo regiona i iuzhnoi chasti Vostochnoi Evropy.

Mitochondrial DNA (mtDNA) restriction polymorphism was examined in Turkmens, Eastern Iranians, and Ukrainians. The gene pools of all populations studied were characterized by the presence of European mtDNA lineages. Mongoloid component observed in Turkmen and Iranian populations with the frequencies of about 20% was represented by groups C, D, and E/G in Turkmens, and by M*, D, A, and B in Iranians. The relative positions of the populations studied, of populations from the Caucasus, Western Iran, and Russian populations from the Krasnodar krai and Belgorod oblast in the space of principal components revealed a geographically specific pattern of the population clustering. The data on mtDNA polymorphism indicated pronounced differentiation of Eastern and Western Iranians. The latter were characterized by a mtDNA group composition similar to that in Eastern Slavs. The historical role of the Caspian populations in the formation of the population of Southeastern Europe is discussed.

[Polymorphism of the Y-chromosome diallelic loci in the ethnic populations of the Altai-Sayan region]. / Polimorfizm diallel'nykh lokusov Y-khromosomy y korennogo naseleniia Altae-Saianskogo nagor'ia.

Using the data on five biallellic Y-chromosome loci (DYS199, 92R7, SRY1532, RBF5 and DYS287) polymorphism, genetic structures of the five Turkic-speaking ethnic groups of the Altai-Sayan highland (Tuvinians, Sojots, Shorians, Khakassians, and Southern Altaians (Altai-Kizhi), were described. The gene pools of the populations examined were characterized by the presence of pronounced paleo-Caucasoid component (92R7-T-lineages). The frequency of this component increased westward, reaching more than 70% in Shorians and Southern Altaians. Haplotype TAT-C (RBF5 locus) was observed in all populations, except Shorians, with the frequencies varying from 5.4% in Altai-Kizhi to 18.8% in Khakassians. The Alu-insertion in the DYS287 locus was revealed only in the Altaian sample with the frequency of 3.3%. It was established that the Altai-Sayan populations studied split into two statistically significantly different groups. One of the groups was represented by Tuvinians, Sojots, and Khakassians, while another one was comprised of Shorians and Altaians.

Use of human CD4 transgenic mice for studying immunogenicity of HIV-1 envelope protein gp120.

HIV-1 envelope protein, gp120, is a major immunogenic protein of the AIDS virus. A specific feature of this protein is its interaction with the receptor protein, human CD4, an important component of the immune system. This interaction might affect the immunogenic properties of the gp 120 and modulate the immune response towards HIV. To test this hypothesis we used human CD4-transgenic mice for immunization with gp120. The dynamics of the immune response towards gp120, CD4 and other proteins was followed. The results show that the primary immune response to gp120 (two weeks) developed somewhat faster in CD4-transgenic mice versus non-transgenic mice. Both animals, however, ultimately mounted the same level of response over time. The primary immune response to gp120 when complexed with soluble CD4 before the immunization, developed similarly in both groups. The secondary immune response was earlier and markedly stronger in non-transgenic mice compared with the transgenic mice where a less efficient memory response to gp120 was observed. The ability of gp120 to directly interact with CD4+ helper lymphocytes appears to affect the humoral response towards this antigen. Moreover, these effects illustrate how viral modulation of these cells may in turn lead to potentially different states of immunological equilibrium.

[Structure of the gene pool of ethnic groups from the Altai-Sayan region from data on mitochondrial polymorphism]. / Struktura genofondov étnicheskikh grupp Altae-Saianskogo nagor'ia po dannym o polimorfizme mitokhondrial'noi DNK.

Using the data on mitochondrial DNA (mtDNA) polymorphism, genetic structures of the four Turkic-speaking ethnic groups of Altai-Sayan highlands, Southern Altaians (Altai-Kizhi), Khakassians, Shorians, and Sojots, were described. Mitochondrial gene pools of the populations examined were characterized by different ratios between Mongoloid (M*, C, D, E, G, A, B, and F) and Caucasoid (H, U, T, J, and K) mtDNA lineages. All the populations studied had a strongly pronounced Mongoloid component, the frequency of which was 88.2% in Sojots, 75.9% in Khakassians, 67.4% in Altaians, and 64.3% in Shorians. Maximum frequency of the Caucasoid component (35.7%) was observed in Shorians. Phylogenetic and statistical analyses of the mtDNA group frequency distribution patterns in the gene pools of the ethnic populations of Altai-Sayan highlands and the adjacent territories showed that the populations of the region fell into three groups. The first group included Khakassians, Tuvinians and Altaians, the second group consisted of Sojots, Buryats, and Mongols, while the third group was composed of Uigurs, Kazakhs, and Kyrgyzes. The isolated position of Shorians among the populations examined can be explained by their different anthropological composition and their presumptive relatedness to Finno-Ugric populations of Siberia.

[Variability in mitochondrial DNA in Russian inhabitants from Krasnodar Krai, Belgorod and the lower Novgorod region]. / Izmenchivost' mitokhondrial'noi DNK v populiatsiiakh russkogo naseleniia Krasnodarskogo kraia, Belgorodskoi i Nizhegorodskoi oblastei.

Mitochondrial DNA (mtDNA) polymorphism was examined in three Russian populations from the European part of Russia (Krasnodar Krai, Belgorod, and Nizhnii Novgorod oblast). This analysis revealed that mitochondrial gene pool of Russians was represented by the mtDNA types belonging to groups H, V, pre-V, HV*, J, T, U, K, I, W, and X. The major groups (average frequency over 5%) were H, V, J, T, and U. Mongoloid admixture in Russians, constituting only 1%, was revealed in the form of mtDNA types of groups C and D. Analysis of the frequency distribution of the mtDNA type groups indicated the absence of genetic differences between the Russian populations studied.