Home About us Contact | |||
European Lineages (european + lineage)
Selected AbstractsFine-scale phylogeographical analysis of Mediterranean Anacamptis palustris (Orchidaceae) populations based on chloroplast minisatellite and microsatellite variationMOLECULAR ECOLOGY, Issue 10 2003S. Cozzolino Abstract The phylogeographical history of the rare marsh orchid Anacamptis palustris (Orchidaceae) was reconstructed using highly polymorphic chloroplast minisatellite and microsatellite loci. Allelic variation at chloroplast microsatellite loci was due to length variation in poly(A/T) repeats and was informative on a regional scale, but was not sufficient to unravel relationships among populations on a local geographical scale. The minisatellite locus, however, was found to be highly variable. Nine distinct repeat types were found and variation in repeat number occurred in five repeat types. The distribution of chloroplast haplotypes, combining microsatellite and minisatellite repeat type variation, provided a clear phylogeographical picture on a large geographical scale, whereas length variation in one highly polymorphic minisatellite repeat type provided fine-scale phylogeographical information. Mediterranean populations could be divided into four main lineages, a western European lineage, a northern and central Italian lineage, a well-isolated southern Italian (Apulian) lineage, and an eastern European lineage. Variation at the most variable minisatellite repeat type N revealed 19 alleles and allowed the study of seed-mediated gene flow and an estimation of the ratio of pollen to seed flow among neighbouring populations. [source] Frequencies of the -330 (T , G) IL-2 and -590 (T , C) IL-4 gene polymorphisms in a population from south-eastern BrazilINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 4 2002R. M. Scarel-Caminaga Summary Polymorphisms in the promoter regions of cytokine genes may affect their transcription. A T/G substitution at position ,330 of the interleukin-2 (IL-2) gene and a T/C substitution at position ,590 of the interleukin-4 (IL-4) gene have been described previously. The ,590 (T , C) IL-4 gene polymorphism was associated with asthma and atopy in US and Japanese populations. Population genetics is a useful tool for determination of the biological significance of genetic polymorphisms. The aim of this study was to investigate the frequencies of polymorphisms in the promoter regions of the IL-2 and IL-4 genes in a population from south-eastern Brazil and to compare them with those published for other populations. Allele frequencies were estimated in 114 unrelated individuals from São Paulo State. These subjects had an average age of 41.2 years (± 12.4 years) and the ethnic composition of the sample was: 78.07% Caucasian, 11.4% Black and 10.53% Mulatto. DNA from subjects was extracted from epithelial buccal cells, and the PCR-RFLP technique was employed to investigate the ,330 (T , G) IL-2 and ,590 (T , C) IL-4 gene polymorphisms. The allele frequency of the IL-2 gene polymorphism obtained in our study was similar to that found in UK Caucasoid groups. The T allele frequency of the IL-4 gene polymorphism observed in the Caucasian Brazilian group was similar to that found in UK and Australian populations, while the frequency observed for the Black Brazilian group was similar to that found in Japanese and Kuwaiti Arab populations. The results for the ,330 (T , G) IL-2 and ,590 (T , C) IL-4 polymorphisms are consistent with the high contribution of European lineages to the population in south-eastern Brazil. [source] Dissecting the molecular architecture and origin of Bayash Romani patrilineages: Genetic influences from South-Asia and the BalkansAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Irena Martinovi, Klari Abstract The Bayash are a branch of Romanian speaking Roma living dispersedly in Central, Eastern, and Southeastern Europe. To better understand the molecular architecture and origin of the Croatian Bayash paternal gene pool, 151 Bayash Y chromosomes were analyzed for 16 SNPs and 17 STRs and compared with European Romani and non-Romani majority populations from Europe, Turkey, and South Asia. Two main layers of Bayash paternal gene pool were identified: ancestral (Indian) and recent (European). The reduced diversity and expansion signals of H1a patrilineages imply descent from closely related paternal ancestors who could have settled in the Indian subcontinent, possibly as early as between the eighth and tenth centuries AD. The recent layer of the Bayash paternal pool is dominated by a specific subset of E1b1b1a lineages that are not found in the Balkan majority populations. At least two private mutational events occurred in the Bayash during their migrations from the southern Balkans toward Romania. Additional admixture, evident in the low frequencies of typical European haplogroups, J2, R1a, I1, R1b1b2, G, and I2a, took place primarily during the early Bayash settlement in the Balkans and the Romani bondage in Romania. Our results indicate two phenomena in the Bayash and analyzed Roma: a significant preservation of ancestral H1a haplotypes as a result of considerable, but variable level of endogamy and isolation and differential distribution of less frequent, but typical European lineages due to different patterns of the early demographic history in Europe marked by differential admixture and genetic drift. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Evolutionary history of the bank vole Myodes glareolus: a morphometric perspectiveBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2010RONAN LEDEVIN The bank vole experienced a complex history during the Quaternary. Repeated isolation in glacial refugia led to the differentiation of several lineages in less than 300 000 years. We investigated if such a recent differentiation led to a significant divergence of phenotypic characters between European lineages, which might provide insight into processes of intraspecific differentiation. The size and shape of the first and third upper molars, and first lower molar, of bank voles genetically attributed to different lineages were quantified using an outline analysis of their occlusal surface. The three teeth present similar trends of decreasing size towards high latitudes. This trend, the inverse of Bergmann's rule, is interpreted as the result of a balance between metabolic efficiency and food availability, favouring small body size in cold regions. Molar shape appeared to differ between lineages despite genetic evidence of suture zones. A mosaic pattern of evolution between the different teeth was evidenced. The analysis of such phenotypic features appears as a valuable complement to genetic analyses, providing a complementary insight into evolutionary processes, such as selective pressures, that have driven the differentiation of the lineages. It may further allow the integration of the paleontological dimension of the bank vole phylogeographic history. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 681,694. [source] |