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Objectives Assuming that the differences between the Andes and the Amazon rainforest at environmental and historical levels have influenced the distribution patterns of genes, languages, and cultures, the maternal and paternal genetic reconstruction of the Peruvian Amazon populations was used to test the relationships within and between these two extreme environments. Materials and Methods We analyzed four Peruvian Amazon communities (Ashaninka, Huambisa, Cashibo, and Shipibo) for both Y chromosome (17 STRs and 8 SNPs) and mtDNA data (control region sequences, two diagnostic sites of the coding region, and one INDEL), and we studied their variability against the rest of South America. Results We detected a high degree of genetic diversity in the Peruvian Amazon people, both for mtDNA than for Y chromosome, excepting for Cashibo people, who seem to have had no exchanges with their neighbors, in contrast with the others communities. The genetic structure follows the divide between the Andes and the Amazon, but we found a certain degree of gene flow between these two environments, as particularly emerged with the Y chromosome descent cluster's (DCs) analysis. Discussion The Peruvian Amazon is home to an array of populations with differential rates of genetic exchanges with their neighbors and with the Andean people, depending on their peculiar demographic histories. We highlighted some successful Y chromosome lineages expansions originated in Peru during the pre-Columbian history which involved both Andeans and Amazon Arawak people, showing that at least a part of the Amazon rainforest did not remain isolated from those exchanges. [ABSTRACT FROM AUTHOR]

Social and cultural factors had a critical role in determining the genetic structure of Europe. Therefore, socially stratified populations may help to focus on specific episodes of European demographic history. In this study, we use uniparental markers to analyse the genetic structure of Partecipanza in San Giovanni in Persiceto (Northern Italy), a peculiar institution whose origins date back to the Middle Ages and whose members form the patrilineal descent of a group of founder families. From a maternal point of view (mtDNA), Partecipanza is genetically homogeneous with the rest of the population. However, we observed a significant differentiation for Y-chromosomes. In addition, by comparing 17 Y-STR profiles with deep-rooted paternal pedigrees, we estimated a Y-STR mutation rate equal to 3.90 * 10 -3 mutations per STR per generation and an average generation duration time of 33.38 years. When we used these values for tentative dating, we estimated 1300-600 years ago for the origins of the Partecipanza. These results, together with a peculiar Y-chromosomal composition and historical evidence, suggest that Germanic populations (Lombards in particular) settled in the area during the Migration Period (400-800 ad, approximately) and may have had an important role in the foundation of this community. [ABSTRACT FROM AUTHOR]

Adaptation to low temperatures has been reasonably developed in the human species during the colonization of the Eurasian landmass subsequent to Out of Africa migrations of anatomically modern humans. In addition to morphological and cultural changes, also metabolic ones are supposed to have favored human isolation from cold and body heat production and this can be hypothesized also for most Neandertal and at least for some Denisovan populations, which lived in geographical areas that strongly experienced the last glacial period. Modulation of non-shivering thermogenesis, for which adipocytes belonging to the brown adipose tissue are the most specialized cells, might have driven these metabolic adaptations. To perform an exploratory analysis aimed at looking into this hypothesis, variation at 28 genes involved in such functional pathway was investigated in modern populations from different climate zones, as well as in Neandertal and Denisovan genomes. Patterns of variation at the LEPR gene, strongly related to increased heat dissipation by mitochondria, appeared to have been shaped by positive selection in modern East Asians, but not in Europeans. Moreover, a single potentially cold-adapted LEPR allele, different from the supposed adaptive one identified in Homo sapiens, was found also in Neandertal and Denisovan genomes. These findings suggest that independent mechanisms for cold adaptations might have been developed in different non-African human groups, as well as that the evolution of possible enhanced thermal efficiency in Neandertals and in some Denisovan populations has plausibly entailed significant changes also in other functional pathways than in the examined one. [ABSTRACT FROM AUTHOR]

Background/Aims: Present-day Iran has long represented a natural hub for the expansion of human genes and cultures. That being so, the overlapping of prehistoric and more recent demographic events interacting at different time scales with geographical and cultural barriers has yielded a tangled patchwork of anthropological types within this narrow area. This study aims to comprehensively evaluate this ethnic mosaic by depicting a fine-grained picture of the Iranian mitochondrial landscape. Methods: mtDNA variability at both HVS-I and coding regions was surveyed in 718 unrelated individuals belonging to 14 Iranian ethnic groups characterized by different languages, religions and patterns of subsistence. Results: A discordant pattern of high ethno-linguistic and low mtDNA heterogeneity was observed for the whole examined Iranian sample. Geographical factors and cultural/linguistic differences actually represented barriers to matrilineal gene flow only for the Baloch, Lur from Yasouj, Zoroastrian and Jewish groups, for which unusual reduced levels of mtDNA variability and high inter-population distances were found. Conclusion: Deep rooting genealogies and endogamy in a few of the examined ethnic groups might have preserved ancestral lineages that can be representative of Proto-Indo-Iranian or prehistoric mitochondrial profiles which survived relatively recent external contributions to the Iranian gene pool. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which discusses a study on the isomatic mutations of isocitrate dehydrogenase 1 and 2 (IDHI and IDH2) in chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) patients.

Background: Polymorphisms of the interleukin-1 (IL-1) gene family have been proposed as potential variants for different diseases including multiple sclerosis (MS). With respect to MS, IL-1 beta (−511 C/T; rs16944), IL-1 beta (+3954 C/T; rs1143634), IL-1 alpha (−889 C/T; rs1800587), IL-1 alpha (+4845 G/T; rs17561), and the variable number of tandem repeats in intron 2 of the IL-1 receptor antagonist (IL-1RN) gene polymorphisms have been studied in different ethnic groups, leading to conflicting results. Methods: This study investigates the association between IL-1 genes and MS by means of 70 markers spanning the 1.1 Mb region where the IL-1 genes map and exploring both the linkage disequilibrium (LD) and the haplotype structure in a case–control design including 410 subjects (160 patients and 250 controls). Results: From allelic/genotypic tests, significant association was found for several polymorphisms including the IL-1 beta (−511 C/T) variant ( P-adjusted = 4.5 × 10−4) and some polymorphisms around the IL-1RN gene. The ‘block-step’ pattern obtained from both the LD map and pairwise analysis identifies four LD regions. Region 1 showed a significant association with MS for the global test ( P < 0.0001) and haplotypes containing the IL-1 beta (−511 C/T) variant still demonstrate highly significant association with disease ( P-value range: 9.9 × 10−5 to 0.02). Conclusions: Our findings support the existence of a causative variant for MS within this candidate region in a representative Italian Caucasian population and, in particular, the role of the IL-1 beta (−511 C/T) variant warrants further investigation. [ABSTRACT FROM AUTHOR]

In this study, we report the genetic variation of autosomal and Y-chromosomal microsatellites in a large Cameroon population dataset (a total of 11 populations) and jointly analyze novel and previous genetic data (mitochondrial DNA and protein coding loci) taking geographic and cultural factors into consideration. The complex pattern of genetic variation of Cameroon can in part be described by contrasting two geographic areas (corresponding to the northern and southern part of the country), which differ substantially in environmental, biological, and cultural aspects. Northern Cameroon populations show a greater within- and among-group diversity, a finding that reflects the complex migratory patterns and the linguistic heterogeneity of this area. A striking reduction of Y-chromosomal genetic diversity was observed in some populations of the northern part of the country (Podokwo and Uldeme), a result that seems to be related to their demographic history rather than to sampling issues. By exploring patterns of genetic, geographic, and linguistic variation, we detect a preferential correlation between genetics and geography for mtDNA. This finding could reflect a female matrimonial mobility that is less constrained by linguistic factors than in males. Finally, we apply the island model to mitochondrial and Y-chromosomal data and obtain a female-to-male migration Nv ratio that was more than double in the northern part of the country. The combined effect of the propensity to interpopulational admixture of females, favored by cultural contacts, and of genetic drift acting on Y-chromosomal diversity could account for the peculiar genetic pattern observed in northern Cameroon. [ABSTRACT FROM AUTHOR]

Coding variants in tumor necrosis factor receptor superfamily member 13B (TNFRSF13B) have been implicated in common variable immunodeficiency (CVID), but the functional effects of such mutations in relation to the development of the disease have not been entirely established. To examine the potential contribution of TNFRSF13B variants to CVID, we have applied an evolutionary approach by sequencing its coding region in 451 individuals belonging to 26 worldwide populations, in addition to controls, patients with CVID and selective IgA deficiency (IgAD) from Italy. The low level of geographical structure for the observed genetic diversity and the several neutrality tests performed confirm the absence of recent population-specific selective pressures, suggesting that TNFRSF13B may be involved also in innate immune functions, rather than in adaptive immunity only. A slight excess of rare derived alleles was found in patients with CVID, and thus some of these variants may contribute to the disease, implying that CVID probably fits the rare variants rather than the common disease/common variant paradigm. This also confirms the previous suggestion that TNFRSF13B defects alone do not cause CVID and that such an extremely heterogeneous immunodeficiency might be more likely related to additional, still unknown environmental and genetic factors. [ABSTRACT FROM AUTHOR]

N-acetyltransferase 2 (NAT2), an important enzyme in clinical pharmacology, metabolizes antibiotics such as isoniazid and sulfamethoxazole, and catalyzes the transformation of aromatic and heterocyclic amines from the environment and diet into carcinogenic intermediates. Polymorphisms in NAT2 account for variability in the acetylator phenotype and the pharmacokinetics of metabolized drugs. Native Americans, settled in rural areas and large cities of Latin America, are under-represented in pharmacogenetics studies; therefore, we sequenced the coding region of NAT2 in 456 chromosomes from 13 populations from the Americas, and two from Siberia, detecting nine substitutions and 11 haplotypes. Variants *4 (37%), *5B (23%) and *7B (24%) showed high frequencies. Average frequencies of fast, intermediate and slow acetylators across Native Americans were 18, 56 and 25%, respectively. NAT2 intra-population genetic diversity for Native Americans is higher than East Asians and similar to the rest of the world, and NAT2 variants are homogeneously distributed across native populations of the continent.The Pharmacogenomics Journal (2007) 7, 144–152. doi:10.1038/sj.tpj.6500407; published online 18 July 2006 [ABSTRACT FROM AUTHOR]

Abstract Ninety isolates of Botrytis cinerea collected from kiwi fruit in orchards and in cold storage were compared phenotypically and genetically. The phenotypic characters evaluated were conidia germination, germ tube length and mycelial growth at 0∘ and 20∘ C. At 20∘ C the two populations showed slight differences but, at 0∘ C, isolates from cold storage appeared to grow significantly faster than isolates from orchards. Isolates were then scored with six genetic markers with the aim of investigating population, genetic structure and the mode of reproduction. We detected no genetic differentiation between isolates from orchards and those from cold storage. This suggests that low temperature adaptation of B. cinerea isolates does not have a genetic basis. By contrast, we found great intra-population genetic diversity, observations suggesting the occurrence of genetic recombination which follows sexual reproduction or alternatively of parasexuality. [ABSTRACT FROM AUTHOR]

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The article presents the study which examined the genetic history of the Italian population as of January 2012. In the study, the resolution power of Y-chromosome uniparental molecular markers is analyzed. Among the methods used in the study are the preliminary surname-based analysis, the TaMan Assays, and the Principal Component Analysis.

The article presents the study which examined the mitochondrial DNA (mtDNA) of the Iranian population as of January 2012. Among the possible ancestors of majority of Iranians are the Aryans and Indo-European nomadic tribes. In the study, the various Iranian ethnic groups that were studied include Balochis, Mazandaranis, and Qashqaees.

The article presents the study which examined the genetic history of the Eastern side of Africa (EA), particularly the origin and spread of the African linguistic phylum, Afro-asiatic (AA). Among the methods used in the study is the spatial principal component analysis (SPCA). The countries included in the study include Ethiopia, Egypt, and Yemen.