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Strong Genetic Differentiation (strong + genetic_differentiation)
Selected AbstractsPopulation genetics and breeding system of Tupistra pingbianensis (Liliaceae), a naturally rare plant endemic to SW ChinaJOURNAL OF SYSTEMATICS EVOLUTION, Issue 1 2010Qin QIAO Abstract The levels and partitioning of genetic diversity and inbreeding depression were investigated in Tupistra pingbianensis, a narrow endemic of southeast Yunnan, China, characterized by a naturally fragmented distribution due to extreme specialization on a rare habitat type. Here genetic diversity and patterns of genetic variation within and among 11 populations were analyzed using amplified fragment length polymorphism markers with 97 individuals across its whole geographical range. High levels of genetic variation were revealed both at the species level (P99= 96.012%; Ht= 0.302) and at the population level (P99= 51.41%; Hs= 0.224). Strong genetic differentiation among populations was also detected (FST= 0.2961; ,II= 0.281), which corresponded to results reported for typical animal-pollinated, mixed selfing, and outcrossing plant species. This result was consistent with mating patterns detected by our pollination experiments. The indirect estimate of gene flow based on ,II was low (Nm= 0.64). Special habitat and its life history traits might play an important role in shaping the genetic diversity and the genetic structure of this species. A pollination experiment also failed to detect significant inbreeding depression upon F1 fruit set, seed weight, and germinate rate fitness-traits. As a naturally rare species, T. pingbianensis is not seriously genetically impoverished and likely to have adapted to tolerating a high level of inbreeding early in its history, we propose this species need only periodic monitoring to ensure their continued persistence, but not intervention to remain viable. [source] Genetic differentiation among the Maculinea species (Lepidoptera: Lycaenidae) in eastern Central EuropeBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2007KATALIN PECSENYE The present study aimed to analyse the level of genetic variation in the eastern Central European (Slovenia, Hungary, and Romania/Transylvania) populations of the Large Blues (Maculinea) to analyse the pattern of differentiation both between and within the species. One objective was to compare the level of differentiation between the two disputed species (Maculinea alcon and Maculinea rebeli) with that among the other species. Imagos were collected from 23 localities in eastern Central Europe in 2002. Enzyme polymorphism was analysed using polyacrylamide gel electrophoresis. Fourteen enzyme loci were studied in all samples. In the analysis of the data, F -statistics and Nei's genetic distances were calculated and a dendrogram (unweighted pair group method with arithmetic mean) was constructed on the basis of the distance matrix. A multivariate analysis of variance was performed to study the pattern of genetic differentiation among the samples. Principal component analysis analysis was also carried out using the allele frequency data of the samples. Our results indicated that the large blues are generally less polymorphic than other European lycaenid butterflies studied. At the same time, the level of genetic differentiation was high, even among local populations within the species. A low level of genetic variation within the populations coupled with strong differentiation among them implies the effect of genetic drift. Strong genetic differentiation of four Maculinea species (M. alcon, Maculinea teleius, Maculinea nausithous, and Maculinea arion) was confirmed. Significant differentiation was not found between M. alcon and M. rebeli. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 11,21. [source] ADAPTIVE POPULATION DIFFERENTIATION IN PHENOLOGY ACROSS A LATITUDINAL GRADIENT IN EUROPEAN ASPEN (POPULUS TREMULA, L.): A COMPARISON OF NEUTRAL MARKERS, CANDIDATE GENES AND PHENOTYPIC TRAITSEVOLUTION, Issue 12 2007David Hall A correct timing of growth cessation and dormancy induction represents a critical ecological and evolutionary trade-off between survival and growth in most forest trees (Rehfeldt et al. 1999; Horvath et al. 2003; Howe et al. 2003). We have studied the deciduous tree European Aspen (Populus tremula) across a latitudinal gradient and compared genetic differentiation in phenology traits with molecular markers. Trees from 12 different areas covering 10 latitudinal degrees were cloned and planted in two common gardens. Several phenology traits showed strong genetic differentiation and clinal variation across the latitudinal gradient, with QST values generally exceeding 0.5. This is in stark contrast to genetic differentiation at several classes of genetic markers (18 neutral SSRs, 7 SSRs located close to phenology candidate genes and 50 SNPs from five phenology candidate genes) that all showed FST values around 0.015. We thus find strong evidence for adaptive divergence in phenology traits across the latitudinal gradient. However, the strong population structure seen at the quantitative traits is not reflected in underlying candidate genes. This result fit theoretical expectations that suggest that genetic differentiation at candidate loci is better described by FST at neutral loci rather than by QST at the quantitative traits themselves. [source] GEOGRAPHIC VARIATION OF GENETIC AND BEHAVIORAL TRAITS IN NORTHERN AND SOUTHERN TÚNGARA FROGSEVOLUTION, Issue 8 2006Heike Pröhl Abstract We use a combination of microsatellite marker analysis and mate-choice behavior experiments to assess patterns of reproductive isolation of the túngara frog Physalaemus pustulosus along a 550-km transect of 25 populations in Costa Rica and Panama. Earlier studies using allozymes and mitochondrial DNA defined two genetic groups of túngara frogs, one ranging from Mexico to northern Costa Rica (northern group), the second ranging from Panama to northern South America (southern group). Our more fine-scale survey also shows that the northern and southern túngara frogs are genetically different and geographically separated by a gap in the distribution in central Pacific Costa Rica. Genetic differences among populations are highly correlated with geographic distances. Temporal call parameters differed among populations as well as between genetic groups. Differences in calls were explained better by geographic distance than by genetic distance. Phonotaxis experiments showed that females preferred calls of males from their own populations over calls of males from other populations in about two-thirds to three-fourths of the contrasts tested. In mating experiments, females and males from the same group and females from the north with males from the south produced nests and tadpoles. In contrast, females from the south did not produce nests or tadpoles with males from the north. Thus, northern and southern túngara frogs have diverged both genetically and bioacoustically. There is evidence for some prezygotic isolation due to differences in mate recognition and fertilization success, but such isolation is hardly complete. Our results support the general observation that significant differences in sexual signals are often not correlated with strong genetic differentiation. [source] Ecological factors drive differentiation in wolves from British ColumbiaJOURNAL OF BIOGEOGRAPHY, Issue 8 2009Violeta Muñoz-Fuentes Abstract Aim, Limited population structure is predicted for vagile, generalist species, such as the grey wolf (Canis lupus L.). Our aims were to study how genetic variability of grey wolves was distributed in an area comprising different habitats that lay within the potential dispersal range of an individual and to make inferences about the impact of ecology on population structure. Location, British Columbia, Canada , which is characterized by a continuum of biogeoclimatic zones across which grey wolves are distributed , and adjacent areas in both Canada and Alaska, United States. Methods, We obtained mitochondrial DNA control region sequences from grey wolves from across the province and integrated our genetic results with data on phenotype, behaviour and ecology (distance, habitat and prey composition). We also compared the genetic diversity and differentiation of British Columbia grey wolves with those of other North American wolf populations. Results, We found strong genetic differentiation between adjacent populations of grey wolves from coastal and inland British Columbia. We show that the most likely factor explaining this differentiation is habitat discontinuity between the coastal and interior regions of British Columbia, as opposed to geographic distance or physical barriers to dispersal. We hypothesize that dispersing grey wolves select habitats similar to the one in which they were reared, and that this differentiation is maintained largely through behavioural mechanisms. Main conclusions, The identification of strong genetic structure on a scale within the dispersing capabilities of an individual suggests that ecological factors are driving wolf differentiation in British Columbia. Coastal wolves are highly distinct and representative of a unique ecosystem, whereas inland British Columbia grey wolves are more similar to adjacent populations of wolves located in Alaska, Alberta and Northwest Territories. Given their unique ecological, morphological, behavioural and genetic characteristics, grey wolves of coastal British Columbia should be considered an Evolutionary Significant Unit (ESU) and, consequently, warrant special conservation status. If ecology can drive differentiation in a highly mobile generalist such as the grey wolf, ecology probably drives differentiation in many other species as well. [source] Consistent geographic structure among multiple nuclear sequences and cpDNA polymorphisms of Cardamine nipponica Franch. et Savat. (Brassicaceae)MOLECULAR ECOLOGY, Issue 13 2008HAJIME IKEDA Abstract Molecular phylogeography has inferred the history of differentiation between regions and/or among populations following the Pleistocene climatic oscillations, mostly based on the genetic structure of organelle DNA. However, such genetic structure only reflects the history of a single gene, and studies based on single-copy genes of nuclear DNA (nDNA) are required for phylogeography, although their efficiency remains unclear. To examine the utility of nDNA loci, the genetic structures of three genes from Cardamine nipponica, which is closely related to the model species Arabidopsis thaliana, were elucidated: the nDNA genes DET1, PHYA, PHYE, as well as chloroplast DNA (cpDNA). In 279 individuals collected from throughout the range of the species, strong genetic differentiation between northern and central Japan was found for all loci. This result suggested that populations in central Japan experienced a different history from those in northern Japan during the Pleistocene climatic oscillations. In addition, the evidence of refugia at the edges of the distribution, where the genetic structure was less influenced by colonization following range expansion, was shown for several loci. The specific genetic structure within the southernmost populations of northern Japan suggested that this region was also isolated during range expansion. Hence, the consistent history among loci and a more detailed history from several loci indicated that cpDNA can represent the history of vicariance and demonstrated the efficiency of single-copy nuclear genes in phylogeography. [source] Genetic diversity and population structure of an insular tree, Santalum austrocaledonicum in New Caledonian archipelagoMOLECULAR ECOLOGY, Issue 7 2005L. BOTTIN Abstract We present a study of the genetic diversity and structure of a tropical tree in an insular system. Santalum austrocaledonicum is endemic to the archipelago of New Caledonia and is exploited for oil extraction from heartwood. A total of 431 individuals over 17 populations were analysed for eight polymorphic microsatellite loci. The number of alleles per locus ranged from 3 to 33 and the observed heterozygosity per population ranged from 0.01 in Maré to 0.74 in Ile des Pins. The genetic diversity was lowest in the most recent islands, the Loyautés, and highest in the oldest island, Grande Terre, as well as the nearby small Ile des Pins. Significant departures from panmixia were observed for some loci,population combinations (per population FIS = 0,0.03 on Grande-Terre and Ile des Pins, and 0,0.67 on Loyautés). A strong genetic differentiation among all islands was observed (FST = 0.22), and the amount of differentiation increased with geographic distance in Iles Loyauté and in Grande Terre. At both population and island levels, island age and isolation seem to be the main factors influencing the amount of genetic diversity. In particular, populations from recent islands had large average FIS that could not be entirely explained by null alleles or a Wahlund effect. This result suggests that, at least in some populations, selfing occurred extensively. Conclusively, our results indicate a strong influence of insularity on the genetic diversity and structure of Santalum austrocaledonicum. [source] High mountains of the Japanese archipelago as refugia for arctic,alpine plants: phylogeography of Loiseleuria procumbens (L.) Desvaux (Ericaceae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2009HAJIME IKEDA According to previous phylogeographic studies, high mountains at low latitudes are important areas for the study of the evolutionary history of arctic,alpine plants in surviving the Pleistocene climatic oscillations. To evaluate this hypothesis, we elucidated the genetic structure of the arctic,alpine plant, Loiseleuria procumbens, in the Japanese archipelago, which corresponds to one of the southernmost limits of its distribution, using 152 individuals from 17 populations that covered the entire distribution of the Japanese archipelago and Sakhalin, in addition to samples from Sweden. Based on 854 bp of chloroplast DNA, we detected eight haplotypes. Along with haplotype distribution, strong genetic differentiation between populations in central and northern Japan was elucidated by a neighbour-joining tree (100%) and spatial analysis of molecular variance (79%), which is consistent with other alpine plants in Japan, regardless of the species' range. In addition, the southernmost populations from northern Japan showed specific genetic structure, although the remaining areas of northern Japan and Sakhalin harboured an homogenous genetic structure. Our results suggest that the populations in central Japan persisted for a long time during the Pleistocene climatic oscillation and that genetic divergence occurred in situ, supporting our hypothesis in conjunction with a previous study of another arctic,alpine plant, Diapensia lapponica subsp. obovata. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 403,412. [source] | ||||||||||