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Mitochondrial DNA Variation (mitochondrial + dna_variation)
Selected AbstractsMitochondrial DNA variation of an isolated population of the Adriatic brook lamprey Lampetra zanandreai (Agnatha: Petromyzontidae): phylogeographic and phylogenetic inferencesJOURNAL OF FISH BIOLOGY, Issue 9 2009V. Caputo Two mitochondrial genes were examined to compare an isolated population of the Adriatic brook lamprey Lampetra zanandreai in central Italy with other populations in the species range (Po plain) and with parasitic and freshwater lampreys. A single haplotype, identical to one in a Venetian sample, was found in 10 individuals from the isolated population. The reduced variability is consistent with a history of dispersal after the Pleistocene expansion of the Po basin. The results support the hypothesis of an origin of L. zanandreai and L. fluviatilis,L. planeri from a common anadromous ancestor. [source] Mitochondrial DNA variation and biogeography of eastern gorillasMOLECULAR ECOLOGY, Issue 9 2001M. I. Jensen-Seaman Abstract Mitochondrial DNA variation in 109 individuals from four populations of wild living gorillas in East Africa was ascertained by sequencing the first hypervariable segment of the control region, or ,d-loop', amplified from noninvasively collected hair and faeces. d- loop haplotypes from eastern gorillas fell into two distinct clades, each with low levels of genetic diversity; most observed haplotypes within each clade differing by only one or two mutations. Both clades show evidence of population bottlenecks in the recent past, perhaps concomitant with the tropical forest reduction and fragmentation brought on by global cooling and drying associated with the last glacial maximum. [source] Stepping stone gene flow in an estuarine-dwelling sparid from south-east AustraliaJOURNAL OF FISH BIOLOGY, Issue 4 2004C. P. Burridge Allozyme and mitochondrial DNA variation was surveyed in Acanthopagrus butcheri to examine the pattern of gene flow among estuaries in south-east Australia. Allozymes distinguished two peripheral estuaries from the remaining six, although the pattern of genetic variation could owe more to selection than reproductive isolation, and overall structure was small (, = 0·012). In contrast, mitochondrial DNA revealed a high degree of genetic structure (, = 0·263), and a significant relationship with geographic isolation. Consequently, contemporary gene flow mostly between adjacent estuaries, consistent with a one-dimensional stepping stone model, is evident in south-east Australia. The data indicate that management of A. butcheri within the study range should be conducted at the scale of individual or geographically proximate estuaries. [source] Geographical patterns of mitochondrial DNA variation in Apis mellifera iberiensis (Hymenoptera: Apidae)JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 1 2008F. Cánovas Abstract An extensive survey of mitochondrial haplotypes in honeybee colonies from the Iberian Peninsula has corroborated previous hypotheses about the existence of a joint clinal variation of African (A) and west European (M) evolutionary lineages. It has been found that the Iberian Peninsula is the European region with the highest haplotype diversity (12 haplotypes detected of the M lineage and 10 of the A lineage). The frequency of A haplotypes decreases in a SW-NE trend, while that of M haplotypes increases. These results are discussed in relation to hypotheses about the African origin of Apis mellifera and an early colonization of west Europe during intermediate Pleistocene glaciation events, followed by a regional differentiation. The extant pattern of haplotype frequency and distribution seems to be influenced at a regional scale by adaptation to local climatic conditions and the mobile beekeeping that has become a large-scale practice during the last decades. Other previous anthropogenic influences (Greek, Roman and Arab colonizations) are thought to be of minor importance in present day populations. Resumen Un extenso estudio de los haplotipos mitocondriales en colonias de la abeja doméstica de la Péninsula Ibérica ha corroborado las hipótesis previas acerca de la existencia de una variación clinal conjunta de los linajes evolutivos africano (A) y europeo occidental (M). Se ha encontrado que la Peninsula Ibérica es la región europea con la mayor diversidad (12 haplotipos detectados pertenecientes al linaje M y 10 al linaje A). La frecuencia de los haplotipos africanos disminuye en la orientación SW-NE, al tiempo que aumenta proporcionalmente la de los M. Estos resultados se analizan en relación a las hipótesis recientes que ubican el origen de Apis mellifera en África, junto con otras que postulan una colonización temprana de esta especie en Europa occidental, seguida de una diferenciación durante el Pleistoceno. El patrón geográfico actual de haplotipos y frecuencias a escala regional, parece estar influido por la adaptación a las condiciones climáticas locales y la trashumancia, práctica que ha adquirido grandes proporciones en las últimas décadas. Otras influencias antrópicas acontecidas como las colonizaciones de griegos, romanos y árabes han tenido posiblemente poca influencia sobre las poblaciones ibéricas actuales. [source] Evolutionary history of lamprey paired species Lampetra fluviatilis (L.) and Lampetra planeri (Bloch) as inferred from mitochondrial DNA variationMOLECULAR ECOLOGY, Issue 9 2007RUTE ESPANHOL Abstract A remarkable trend in the evolution of lampreys is the occurrence in most genera of ,paired species', in which the parasitic anadromous lampreys are believed to have given rise to nonparasitic freshwater resident populations. The present work examines the phylogeography of the European paired species Lampetra fluviatilis and Lampetra planeri, in an attempt to elucidate species pair evolutionary history. We studied sequence variation in cytochrome b and ATPase 6, 8 mitochondrial genes in 63 individuals from 21 localities of the paired species throughout their distribution range. Results from the phylogenetic and nested clade analyses were largely consistent, suggesting the existence of three major evolutionary lineages: lineage I and possibly lineage II are widespread throughout Europe, while the most ancestral lineage III is apparently restricted to the Iberian Peninsula. The high genetic diversity observed in the Iberian Peninsula is probably the result of refugial persistence and subsequent accumulation of variation over several ice ages, whereas the low levels of genetic diversity observed in central and northern Europe should reflect a rapid postglacial colonization. Results suggest that L. planeri originated within at least two distinct evolutionary lineages, rejecting the single origin hypothesis. The observed lack of taxa monophyly within lineage I may be the result of ongoing gene flow if the two taxa are alternate life-history forms of a single species. However, structure within lineage I is also consistent with the hypothesis of divergence of taxa after postglacial dispersion (around 2000 generations ago) with incomplete lineage sorting. Further testing of the alternative hypotheses is warranted. [source] Comparative phylogeography of eastern chipmunks and white-footed mice in relation to the individualistic nature of speciesMOLECULAR ECOLOGY, Issue 13 2006KEVIN C. ROWE Abstract Palaeoecological studies have demonstrated that ecological communities as a whole did not remain stable throughout the climatic fluctuations of the Quaternary. The result is that long-term associations of species cannot be inferred by contemporary associations in ecological communities. Therefore, the evolutionary significance of any contemporary ecological interactions among species and of the biotic community within which species have evolved also cannot be assumed from contemporary conditions. Comparative phylogeographic data provide a method to identify species within ecological communities that have shared biogeographic histories. We present an example of a long-term association between populations of two mammalian species, eastern chipmunks (Tamias striatus) and white-footed mice (Peromyscus leucopus), which are commonly associated with deciduous forest habitats. The distribution of mitochondrial DNA variation in T. striatus and P. leucopus from previously glaciated regions of the eastern United States support the hypothesis that, in at least part of their range, genetic lineages of the two species have expanded from similar population sources since the Last Glacial Maximum. In addition, the spatial concordance of genetic lineages of T. striatus and P. leucopus with the oak-savannah forest formations of Wisconsin and Illinois, suggest that populations associated with this community colonized the area in association with a set of arboreal species that comprise their deciduous forest habitat. [source] How mitochondrial DNA diversity can help to understand the dynamics of wild-cultivated complexes.MOLECULAR ECOLOGY, Issue 12 2001The case of Medicago sativa in Spain Abstract In order to clarify the relationships (genetic exchange and shared ancestry) between natural and cultivated populations of alfalfa (Medicago sativa L.) in Spain, we investigated the patterns of mitochondrial DNA variation (characterized through restriction fragment length polymorphism) for 248 individuals in seven natural and six cultivated populations of this species. Mitochondrial variation was evidenced in both natural and cultivated populations of M. sativa. Among the seven mitotypes idengified in the species, two were specific of the natural populations, a result attesting the fact that the Spanish wild form of M. sativa is an original genetic pool compared to the cultivated one. Other mitotypes were observed in both natural and cultivated populations, suggesting the occurrence of gene flow through seeds from cultivated towards natural populations. Comparisons with previously gathered nuclear and phenotypic data give insights into the different evolutionary forces acting on the different kinds of Spanish natural populations examined so far. [source] The comparative phylogeography of Neotropical mammals: patterns of intraspecific mitochondrial DNA variation among bats contrasted to nonvolant small mammalsMOLECULAR ECOLOGY, Issue 9 2000A. D. Ditchfield Abstract The major aim of this study was to compare the phylogeographic patterns of codistributed bats and small nonvolant Neotropical mammals. Cytochrome b sequences (mitochondrial DNA) were obtained for a total of 275 bats representing 17 species. The tissue samples were collected in coastal Brazil, and were available from Mexico and the Guyana. The study concentrates on four species (Artibeus lituratus, Carollia perspicillata, Sturnira lilium and Glossophaga soricina) which were well represented. The other 13 species were sequenced to test the generality of the patterns observed. In general, sequence divergence values within species were low, with most bat species presenting less than 4% average sequence divergence, and usually between 1 and 2.5%. Clades of highly similar haplotypes enjoyed broad distribution on a continental scale. These clades were not usually geographically structured, and at a given locality the number of haplotypes was high (8,10). As distance increased, some moderately divergent clades were found, although the levels of divergence were low. This suggests a geographical effect that varied depending on species and scale. Small nonvolant mammals almost invariably have high levels of sequence divergence (> 10%) for cytochrome b over much shorter distances (< 1000 km). The grain of intraspecific variation found in small nonvolant mammals is much finer than in bats. Low levels of geographical structuring cannot be attributed to a slower evolutionary rate of bat DNA in relation to other mammalian taxa. The phylogeographic pattern of bats contrasts sharply with the pattern found for Neotropical rodents and marsupials. [source] Mitochondrial DNA patterns in the Iberian Northern plateau: Population dynamics and substructure of the Zamora provinceAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Luis Alvarez Abstract Several studies have shown the importance of recent events in the configuration of the genetic landscape of a specific territory. In this context, due to the phenomena of repopulation and demographic fluctuations that took place in recent centuries, the Iberian Northern plateau is a very interesting case study. The main aim of this work is to check if recent population movements together with existing boundaries (geographical and administrative) have influenced the current genetic composition of the area. To accomplish this general purpose, mitochondrial DNA variations of 214 individuals from a population located in the Western region of the Iberian Northern plateau (the province of Zamora) were analyzed. Results showed a typical Western European mitochondrial DNA haplogroup composition. However, unexpected high frequencies of U5, HV0, and L haplogroups were found in some regions. The analyses of microdifferentiation showed that there are differences between regions, but no geographic substructure organization can be noticed. It can be stated that the differences observed in the genetic pool of the sampled area at regional level results from the mixture of different populations carrying new lineages into this area at different points in history. Am J Phys Anthropol 142:531,539, 2010. © 2010 Wiley-Liss, Inc. [source] Prehistorical East,West admixture of maternal lineages in a 2,500-year-old population in XinjiangAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Fan Zhang Abstract As an area of contact between Asia and Europe, Central Asia witnessed a scenario of complex cultural developments, extensive migratory movements, and biological admixture between West and East Eurasians. However, the detanglement of this complexity of diversity requires an understanding of prehistoric contacts of the people from the West and the East on the Eurasia continent. We demonstrated the presence of genetic admixture of West and East in a population of 35 inhabitants excavated in Gavaerk in southern Xinjiang and dated 2,800,2,100 years before present by analyzing their mitochondrial DNA variations. This result indicates that the initial contact of the East and the West Eurasians occurred further east than Central Asia as early as 2,500 years ago. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] | ||||||||||