Polymorphisms at locus D1S80 and other hypervariable regions in the analysis of Eastern European ethnic group relationships.

BACKGROUND: It has been hypothesized that, whereas many loci are used to generate phylogenetic relationships, the utilization of those that yield the most information could increase the accuracy of any multilocus phylogenetic reconstruction. Among these is the D1S80 hypervariable minisatellite region, which has been shown to be highly polymorphic globally, and it was of interest to compare the nearest neighbours and distant populations of Eastern Europe using the D1S80 polymorphism. AIM: The study evaluated the capacity of the D1S80 locus to discriminate between populations from different ethnic groups in Russia and the Republic of Belarus, revealing the polymorphism parameters of the populations studied. SUBJECTS AND METHODS: Hypervariable D1S80 minisatellite polymorphism was studied in 15 populations, belonging to six distinct ethnic groups from the Russian Federation (Russians, Komis, Maris, Udmurts, Kalmyks, and Yakuts) and the Republic of Belarus (Byelorussians). The data were analysed with other results reported for D1S80 polymorphism among Eastern Europeans, and were analysed together with those previously reported for Eastern European populations for the 3'ApoB, DMPK, DRPLA, and SCA1 hypervariable loci. Genetic diversity analysis was carried out using multidimensional scaling (MDS) of Nei's genetic distances. RESULTS: The Eastern Slavonic populations (Russians, Ukrainians, and Byelorussians) are closely associated, and outermost from populations of Asian origin (Kalmyks and Yakuts). The populations that inhabit the Volga-Ural region (Udmurt, Komi, Mari, and Bashkir ethnic groups) revealed intermediate characteristics. CONCLUSION: The clustering of populations demonstrated here using D1S80 alone coincides with the analysis of five hypervariable region (HVR) loci, and is consistent with linguistic, geographic, and ethnohistorical data. These results are in agreement with most studies of mtDNA, Y-chromosomal, and autosomal DNA diversity in Eastern Europe. The D1S80 locus is convenient for population analyses, and may be used as part of a set of similar markers, which should allow the easy resolution of small differences in population structures.

Variability of the 3'APOB minisatellite locus in Eastern Slavonic populations.

OBJECTIVE: To describe and compare the 3' apolipoprotein (Apo) B minisatellite allele frequency distributions of Eastern Slavonic populations and their Uralic, Altaic, and Caucasian speaking neighbors. METHODS: Healthy individuals of 10 populations among Russians, Byelorussians, Komis and Bashkirs were studied for variable number tandem repeats (VNTRs) in the 3'ApoB minisatellite region. Data were analyzed with other results reported for this polymorphism in eastern Europeans and Siberians. RESULTS: Allele frequency spectra in Eastern Slavonic, Northern Caucasian and Finno-Ugric speaking populations are bimodal with the main peak in alleles 34-36 and a secondary mode around allele 48, whereas Altaic speaking populations have a unimodal allele frequency distribution with a peak of around 34-36 VNTRs. Population relationships were revealed using both multidimensional scaling analysis (based on Nei's genetic distance estimate) and testing for genetic heterogeneity. Eastern Slavonic populations (Russians, Ukrainians, Byelorussians) were most closely related to each other and formed a separate tight clusterwhen plotted. Testing for genetic heterogeneity among the Eastern Slavonic ethnic groups revealed maximum diversity among Byelorussians, followed by Russians, then Ukrainians. The 3'ApoB minisatellite variability reveals little heterogeneityamong the Eastern Slavonic ethnic groups, whereas there wassignificant heterogeneity for Northern Caucasian and Altaic speakers. CONCLUSION: For this 3'ApoB polymorphism the Eastern Slavonic populations, despite their wide geographical distribution, appear to be much more homogenous than other ethnic groups of the region. Multidimensional scaling analysis of these data allowed for differentiation between individual populations from an ethnic group even if there is little heterogeneity.

p53 polymorphisms in Russia and Belarus: correlation of the 2-1-1 haplotype frequency with longitude.

Four different polymorphisms in the human p53 gene (a 16-bp duplication in intron 3, and three RFLPs: for Bsh1236I at codon 72, for MspI in intron 6 and for BamHI in the 3' flanking region) and extended haplotypes were studied in nine geographically diverse populations from Russia and Belarus. The Yakuts differed from all other populations, as they had a significantly higher frequency of the BamHI A1 allele. Most populations did not differ significantly from each other in the frequency of the Bsh1236I polymorphism. The 16-bp duplication A1 allele and MspI A2 allele frequencies were significantly higher in the Yakut and Khant populations. Linkage disequilibrium values (D') between BamHI and other polymorphic sites were not significant in many cases; for this reason we have used the 16 bp-Bsh1236I-MspI haplotype frequencies only. Of eight possible haplotypes, five were observed in the populations investigated. Haplotype 1-2-2 was the most frequent in all populations. The next most common haplotype, 1-1-2, was present at very similar frequencies among the Byelorussians and Russians from Smolensk, but was more frequent in other populations. The frequency of haplotype 2-1-1 showed a nearly continuous decrease from West to East (from 17.857% among the Byelorussians to 0.685% in the Yakuts from the Verkhoyansk) and correlated with longitude (Spearman's r = -0.8667, P = 0.0025), which may be due to natural selection and adaptation. The relationships among populations were evaluated by means of Nei's D(A) distances for the 16 bp-Bsh1236I-MspI haplotype frequencies. Based on the multidimensional scaling analysis a correlation between p53 haplotype frequencies and ethnicity is supposed.

Role of the autonomic nervous system in the development of cardiac arrhythmias in cats with acute myocardial ischemia receiving thyroliberin.

The role of the autonomic nervous system in the development of ischemic cardiac arrhythmias was studied in acute experiments on cats receiving thyrotropin-releasing hormone. Bilateral vagotomy attenuated, while bilateral transection of cardiac branches of the stellate ganglia completely abolished the antiarrhythmic effect of thyrotropin-releasing hormone.

Apolipoprotein B 3'-VNTR polymorphism in Eastern European populations.

Apolipoprotein B 3' (3' ApoB) minisatellite polymorphism was studied in healthy unrelated individuals from the Russian Federation and the Republic of Belarus, in 10 populations from five ethnic groups: Russians, Byelorussians, Adygeis, Kalmyks and Yakuts. The analysis was carried out using PCR and electrophoresis followed by silver staining. Overall, 25 alleles of the 3' ApoB minisatellite, ranging from 25 to 55 repeats, were detected. Heterozygosity indices were high and varied from 0.73 to 0.84. The distributions of alleles of this minisatellite in the Caucasoid populations (Russians, Byelorussians and Adygeis) had a bimodal character, whereas that for Mongoloid populations (Kalmyks and Yakuts) had a unimodal distribution. Nei's genetic distances between the populations studied and some reference populations of Europe and Asia were estimated. Despite their allele distribution homogeneity, different East Slavonic ethnic groups were clearly resolved by multidimensional analyses. The East Slavonic and Adygei populations revealed a high similarity with European Caucasoids. The Mongoloid populations (Kalmyks and Yakuts) were considerably different from those of the European Caucasoid populations, but were similar to other Asian Mongoloid populations. The results demonstrate the variability of 3' ApoB minisatellite polymorphism not only in distant populations but also, to a certain extent, in genetically relative ones.

Effect of thyrotropin-releasing hormone on activity of bulbar cardiovascular neurons.

Acute experiments on narcotized cats showed that intravenous injection of thyrotropin-releasing hormone (20 microg/kg) inhibited discharge activity of most afferent neurons and interneurons in the bulbar cardiovascular center.

Effect of TRH on the development of ischemic cardiac arrhythmias in cats.

Acute experiments on cats showed that intravenous injection of thyrotropin-releasing hormone prevented blood pressure drop and produced a pronounced antiarrhythmic effect.

Effect of thyrotropin-releasing hormone on the development of cardiac arrhythmias during stimulation of sensorimotor cortex in cats.

Preliminary intravenous injection of thyrotropin-releasing hormone in a dose of 20 g/kg to cats with developing myocardial ischemia during stimulation of the cerebrocortical sensorimotor zone had a pronounced antiarrhythmic effect.

Polymorphism of trinucleotide repeats in loci DM, DRPLA and SCA1 in East European populations.

A normal polymorphism at three triplet repeat loci (myotonic dystrophy (DM), dentatorubral-pallidoluysian atrophy (DRPLA) and spinocerebellar ataxia type 1 (SCA1)) were examined in healthy unrelated individuals from the Siberian Yakut (Mongoloid) population, the Adygei (Caucasian) population and nine East European populations: populations from Russia (Holmogory, Oshevensk, Kursk, Novgorod, Udmurts, Bashkir), two Ukrainian populations (Lviv and Alchevsk) and one Belarussian. The distribution of alleles for DRPLA and SCA1 were similar for all East-European populations. For the DM locus, East European populations had typical allele distribution profiles with two modes, (CTG)5 and (CTG)11-14, but some differences were found for the Bashkir population where alleles containing 11-14 CTG repeats had relatively higher frequency. The Yakut population had different allele spectra for all types of repeats studied. Higher heterozygosity levels and insignificant differences between expected and observed heterozygosity were found for all tested loci. The latter led us to suggest that the trinucleotide repeat loci analysed are not influenced by selection factors and could be useful for genetic relationship investigations in different populations.