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In this article we present the results of a cross-cultural study of non-verbal intelligence in primary school students. Significant differences with the effect size of 9% were found in non-verbal intelligence scores of 1057 students from Russia and Kyrgyzstan. The differences were also found for city and countryside residents (effect size of 10%). These results might be explained both by the features of educational systems and socio-economic development level in Russia and Kyrgyzstan.

A detailed analysis of northern Asian mtDNA phylogeography which confirmed the lack of lineages ancestral to major Eurasian haplogroups M, N, and R in southern Siberia and also ruled out the existence to northern Asian route is presented.

We investigated the frequency of different repeat-length alleles of the trinucleotide CAG microsatellite repeat in the coding sequence of the nuclear gene for the catalytic subunit of mitochondrial DNA polymerase gamma (POLG) in 12 ethnic groups from northern Eurasia. The population sample consisted of 1,330 individuals from 3 large geographic areas: Europe, Southwest Asia, and Siberia/East Asia. We found that the 10-repeat allele of the POLG gene is the most frequent in all analyzed populations, with a frequency of 88-96%. The heterozygosity level ranges from 22% in Europe to 13.6% in Southwest Asia with the lowest value of 7.4% in Siberia/East Asia. The present study provides evidence of clinal distribution of POLG gene heterozygosity in North Eurasian populations. In general, we found an extremely low variability of the trinucleotide CAG microsatellite repeat, suggesting that purifying selection acts against deleterious alleles, although low mutability of the repeated region cannot be ruled out. KEY WORDS: MITOCHONDRIAL DNA MUTATIONS, POLYMERASE GAMMA (POLG), HUMAN POPULATIONS, GENETIC DIVERSITY, NORTHERN EURASIAN ETHNIC GROUPS, RUSSIANS, POLES, BOSNIANS, PERSIANS, KURDS, TAJIKS, BURYATS, SHORS, ALTAIANS, TUVINIANS, KOREANS, MONGOLIANS, SIBERIANS., The last decade revealed rapid progress in the investigation of population variability of the maternally inherited mitochondrial DNA (mtDNA). The accumulation of mutations (deletions, insertions, nucleotide substitutions) in human mtDNA [...]

The two-spot ladybird beetle Adalia bipunctata (Coleoptera: Coccinellidae) is host to four different intracellular maternally inherited bacteria that kill male hosts during embryogenesis: one each of the genus Rickettsia ([alpha]-Proteobacteria) and Spiroplasma (Mollicutes) and two distinct strains of Wolbachia ([alpha]-Proteobacteria). The history of infection with these male-killers was explored using host mitochondrial DNA, which is linked with the bacteria due to joint maternal inheritance. Two variable regions, 610 bp of cytochrome oxidase subunit I and 563 bp of NADH dehydrogenase subunit 5, were isolated from 52 A. bipunctata with known infection status and different geographic origin from across Eurasia. Two outgroup taxa were also considered. DNA sequence analysis revealed that the distribution of mitochondrial haplotypes is not associated with geography. Rather, it correlates with infection status, confirming linkage disequilibrium between mitochondria and bacteria. The data strongly suggest that the Rickettsia male-killer invaded the host earlier than the other taxa. Further, the male-killing Spiroplasma is indicated to have undergone a recent and extensive spread through host populations. In general, male-killing in A. bipunctata seems to represent a highly dynamic system, which should prove useful in future studies on the evolutionary dynamics of this peculiar type of symbiont-host association.

Causes of male-killing have been studied in a sample of the two-spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae) from Russia. Thirty-six matrilines were tested looking for the four male-killing symbionts that are known to infect the species. All four were found. They are Spiroplasma, Rickettsia, and two Wolbachia strains. Possible explanations are offered.

We investigated the frequency of different repeat-length alleles of the trinucleotide CAG microsatellite repeat in the coding sequence of the nuclear gene for the catalytic subunit of mitochondrial DNA polymerase gamma (POLO) in 12 ethnic groups from northern Eurasia. The population sample consisted of 1,330 individuals from 3 large geographic areas: Europe, Southwest Asia, and Siberia/East Asia. We found that the 10-repeat allele of the POLO gene is the most frequent in all analyzed populations, with a frequency of 88-96%. The heterozygosity level ranges from 22% in Europe to 13.6% in Southwest Asia with the lowest value of 7.4% in Siberia/East Asia. The present study provides evidence of clinal distribution of POLG gene heterozygosity in North Eurasian populations. In general, we found an extremely low variability of the trinucleotide CAG microsatellite repeat, suggesting that purifying selection acts against deleterious alleles, although low mutability of the repeated region cannot be ruled out. [ABSTRACT FROM AUTHOR]

Assesses the history of infection among different male-killing bacteria in two-spot ladybird beetle Adalia bipunctata. Visualization of infection through mitochondrial DNA sequence analysis; Confirmation on the linkage disequilibrium between mitochondria ans bacteria; Analysis on genetic differentiation.

Presents several letters to the editor about genetic studies. Mutation screen in individuals with androgenetic alopecia; Effect of polymorphism on hairless genes; Presence of mitochondrial haplogroup X in Altaians from South Siberia.