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1.
Tribolium castaneum, a pest of stored grain, has a uniform morphology, preventing the visual identification of strains from different areas. Polymorphisms in the nucleotide sequences of the mitochondrial genes of this species were examined, and combined into seven haplotypes among the test insect specimens originating from Japan, Thailand, and Canada. These results suggested the potential for geographical differentiation.  相似文献   

2.
Aim We study the population differentiation and phylogeography of the Temminck’s Stint (Calidris temminckii). Specifically, we seek signs of past and present population size changes and dispersal events and evaluate management and conservation unit status of the populations. We also study the possibility of introgression as the origin of two mitochondrial DNA (mtDNA) lineages found and estimate the divergence time of the lineages. Location Northern Eurasia. Methods We analysed 583 bp of mtDNA control region domains I and II and 11 microsatellite loci from 13 localities throughout the breeding range. In addition, we used mitochondrial cytochrome c oxidase subunit I (COI), a barcoding gene, to search for signs of introgression. Results More population differentiation was found from microsatellites than from mtDNA, although differentiation was weak in both markers. Signs of past population growth were observed, in addition to more recent decline in some areas. Both control region and COI sequences revealed two maternal lineages coexisting in Fennoscandia and in north‐west Siberia. No signs of introgression were detected. Lineage divergence time was estimated to have occurred during the glacial periods of Pleistocene. Main conclusions Slight differences in mtDNA and microsatellite differentiation and diversity may reflect different features – such as the mutation rate and effective population size – of the markers used, or female‐biased dispersal pattern and high male site‐fidelity of the species. The coexistence of the two mitochondrial lineages is most likely a consequence of post‐glacial mixing of two refugial Pleistocene populations. Based on genetic information alone, global conservation concerns are not imminent. However, fast decline of a marginal Bothnian Bay population and the smallness and remoteness of a Central Yakutian population warrant conservation actions.  相似文献   

3.
Extensive population structuring is known to occur in Anopheles darlingi , the primary malaria vector of the Neotropics. We analysed the phylogeographic structure of the species using the mitochondrial cytochrome oxidase I marker. Diversity is divided into six main population groups in South America: Colombia, central Amazonia, southern Brazil, south-eastern Brazil, and two groups in north-east Brazil. The ancestral distribution of the taxon is hypothesized to be central Amazonia, and there is evidence of expansion from this region during the late Pleistocene. The expansion was not a homogeneous front, however, with at least four subgroups being formed due to geographic barriers. As the species spread, populations became isolated from each other by the Amazon River and the coastal mountain ranges of south-eastern Brazil and the Andes. Analyses incorporating distances around these barriers suggest that the entire South American range of An. darlingi is at mutation–dispersal–drift equilibrium. Because the species is distributed throughout such a broad area, the limited dispersal across some landscape types promotes differentiation between otherwise proximate populations. Moreover, samples from the An. darlingi holotype location in Rio de Janeiro State are substantially derived from all other populations, implying that there may be additional genetic differences of epidemiological relevance. The results obtained contribute to our understanding of gene flow in this species and allow the formulation of human mosquito health protocols in light of the potential population differences in vector capacity or tolerance to control strategies.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 854–866.  相似文献   

4.
The California Floristic Province (CFP) is considered a global biodiversity hotspot because of its confluence of high species diversity across a wide range of threatened habitats. To understand how biodiversity hotspots such as the CFP maintain and generate diversity, we conducted a phylogeographic analysis of the flightless darkling beetle, Nyctoporis carinata, using multiple genetic markers. Analyses of both nuclear and mitochondrial loci revealed an east–west genetic break through the Transverse Ranges and high genetic diversity and isolation of the southern Sierra Nevada Mountains. Overall, the results obtained suggest that this species has a deep evolutionary history whose current distribution resulted from migration out of a glacial refugium in the southern Sierra Nevada via the Transverse Ranges. This finding is discussed in light of similar genetic patterns found in other taxa to develop a foundation for understanding the biodiversity patterns of this dynamic area. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 424–444.  相似文献   

5.
We performed a molecular phylogenetic analysis of the ground beetles Apatrobus (Carabidae), endemic to Japan, using the mitochondrial cytochrome c oxidase subunit I (COI) and the nuclear 28S rRNA (28S) genes. We focused on the species divergence in Kyushu, Shikoku and western Honshu and used 15 of 19 species and three populations with undetermined species in the DNA analysis. The gene trees showed that, of the Apatrobus species studied, A. hayachinensis Nakane from northern Honshu was not included in the monophyletic group of the other Apatrobus species and likely to be of a different genus. Divergence time estimation suggested that Apatrobus species excluding A. hayachinensis diverged 5.2 million years ago and the subsequent divergence of species occurred during the Pliocene and Pleistocene. In each of the main islands, Kyushu, Shikoku and Honshu, two or more distinct lineages occurred and all species had restricted distribution areas, suggesting that ancient dispersal and vicariance among the three main islands resulted in the nested biogeographical pattern of species distribution.  相似文献   

6.
The Strait of Gibraltar is one of the major barriers to gene flow between land masses of Europe and Africa at the western end of the Mediterranean. Since the opening of the Strait at the end of the Miocene 5.33 million years ago (Mya) it has exerted a strong influence on the dispersal and colonization of whole biotas, particularly with regard to the retreat of organisms during glaciation peaks and the northward colonization events during the warm periods of Pleistocene. The aim of this study is to elucidate the influence of the Strait of Gibraltar in the gene flow among populations of two tiger beetle species collected in Morocco, Cicindela campestris (L. 1758) and Lophyra flexuosa (Fabricius 1787), with regard to both new and published data from populations of southern Iberia. The phylogeographic analysis showed that Moroccan haplotypes of L. flexuosa belonged to a single coastal mitochondrial clade and that populations at both sides of` the Strait of Gibraltar were genetically well connected. The haplotype network of C. campestris showed that Moroccan populations made up a robust cluster clearly differentiated from those of Iberian and other European populations. These differences are thought to reflect the distinct evolutionary history (dispersal capacity, ecological strategies) of both species, as L. flexuosa shows an almost continuous distribution on the coasts located at both sides of the West Mediterranean, whereas C. campestris shows a patchy distribution and prefers montane habitats in the Western Palaearctic.  相似文献   

7.
Coastal populations are often connected by unidirectional current systems, but the biological effects of such asymmetric oceanographic connectivity remain relatively unstudied. We used mtDNA analysis to determine the phylogeographic origins of beach‐cast bull‐kelp (Durvillaea antarctica) adults in the Canterbury Bight, a 180 km coastal region devoid of rocky‐reef habitat in southern New Zealand. A multi‐year, quantitative analysis supports the oceanographically derived hypothesis of asymmetric dispersal mediated by the north‐flowing Southland Current. Specifically, 92% of beach‐cast specimens examined had originated south of the Bight, many drifting north for hundreds of kilometres, and some traversing at least 500 km of ocean from subantarctic sources. In contrast, only 8% of specimens had dispersed south against the prevailing current, and these counter‐current dispersers likely travelled relatively small distances (tens of kilometres). These data show that oceanographic connectivity models can provide robust estimates of passive biological dispersal, even for highly buoyant taxa. The results also indicate that there are no oceanographic barriers to kelp dispersal across the Canterbury Bight, indicating that other ecological factors explain the phylogeographic disjunction across this kelp‐free zone. The large number of long‐distance dispersal events detected suggests drifting macroalgae have potential to facilitate ongoing connectivity between otherwise isolated benthic populations.  相似文献   

8.
1 Paropsis atomaria Olivier represents an emergent pest of Eucalyptus plantations in Queensland and New South Wales, Australia. Most prior studies on the biology and control of P. atomaria have centred on populations from Canberra in the Australian Capital Territory, but the biological relationship between beetles from Canberra and those from up to 1500 km further north are unknown. 2 DNA markers were used to determine whether P. atomaria from Canberra are the same biological species as those from Eucalyptus forestry plantations in northern New South Wales and Queensland, where the beetle has become an important pest. Using the mitochondrial gene, cytochrome c oxidase I (COI), individuals collected from across the distribution of P. atomaria were investigated for haplotype diversity and levels of mitochondrial divergence. 3 Within P. atomaria, genetic distance averaged 0.5% across 23 unique haplotypes for 93 individuals, with an average of 14% difference between P. atomaria and the outgroup species, Paropsis obsoleta. Significant genetic structure was observed relative to geographical distribution, but not with respect to host plant species of origin. Greatest divergence was between the southern‐most sample site (Canberra) and northern sites in New South Wales and Queensland, indicating reduced gene flow between these regions. 4 Individuals from across eastern Australia belong to the same genetic species with population substructuring evident. Consequently, there is no evidence to suggest cryptic species complexes exist within the currently defined taxon. Continued implementation of control strategies for P. atomaria across its distribution is appropriate.  相似文献   

9.
Using mitochondrial DNA cytochrome c oxidase subunit I and nuclear DNA 28S rRNA data, we explored the phylogenetic relationships of the family Pimoidae (Arachnida: Araneae) and tested the North America to Asia dispersal hypothesis. Sequence data were analysed using maximum parsimony and Bayesian inference. A phylogenetic analysis suggested that vicariance, instead of dispersal, better explained the present distribution pattern of Pimoidae. Times of divergence events were estimated using penalized likelihood method. The dating analysis suggested that the emergence time of Pimoidae was approximately 140 million years ago (Ma). The divergence time of the North American and Asian species of Pimoa was approximately 110 Ma. Our phylogenetic hypothesis supports the current morphology‐based taxonomy and suggests that the cave dwelling might have played an important role in the speciation of pimoids in arid areas.  相似文献   

10.
The Quaternary period was marked by considerable changes in climate. Such palaeoclimatic changes affected the population dynamics of many species, both in the Northern and in the Southern Hemisphere. However, the extent of these impacts on the demographic patterns of Neotropical species presenting different ecological requirements remains unclear. Drosophila maculifrons DUDA 1947 belongs to the guaramunu group of Drosophila and represents a potential indicator of the genetic consequences caused by the climatic fluctuations of the Quaternary, because it seems to be sensitive to temperature and humidity shifts. The aim of this study was to evaluate the evolutionary processes subjacent to the patterns of intraspecific diversity and structure of different populations of D. maculifrons. In total, 152 individuals were collected in the south and south‐east Brazil. Phylogenetic and phylogeographical analyses were performed based on sequences of COI and COII mitochondrial genes. In general, the results pointed to Brazilian populations of D. maculifrons being extremely impoverished in terms of mitochondrial diversity and population structure, which could be explained by a recent population expansion event dated to approximately 12 000 years ago. In fact, with the assistance of species palaeo‐distribution modelling strategies, it was possible to infer that most of the sampled region did not present the D. maculifrons environmental suitability requirements at least during the period of the Last Glacial Maximum. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112 , 55–66.  相似文献   

11.
The phylogeography of Simulium siamense complex was inferred from mitochondrial DNA sequences. A 586‐bp fragment of the cytochrome oxidase I was sequenced for 92 individuals from 13 populations throughout Thailand, representing five cytoforms (A, B, C, F and G). The cytoforms are not genetically different at the molecular level except for cytoform B, which is genetically distinct from the others. This might indicate that cytoform B is a distinct species. Further morphological and molecular work using other genes is needed to clarify this. Our results also argue for the need of integrated approach, both cytological and molecular studies to understanding biodiversity of black flies. The star‐like shape of the mtDNA genealogy is consistent with the sudden population expansion of the mismatch distribution analysis and large negative values of Fu's Fs and Tajima's D‐tests, indicating a population demographic expansion. The expansion time is estimated to be in the late Pleistocene (about 120 000 years ago). Therefore, the overall low level of genetic structure could be due to sharing a recent history. The ancestral haplotype was found in the mountainous area in northeastern Thailand, suggesting that this area could have been the refugium of the species complex during the Pleistocene glaciations. Our results are consistent with previous findings about population expansion in response to the Pleistocene climatic change, thus revealing the importance of this historical event in shaping the genetic structure and diversity of Southeast Asian mainland species.  相似文献   

12.
We investigated here the relation of environmental variables with the distribution of mitochondrial lineages using a bark beetle species of Mediterranean distribution as a model. We analysed a total number of 460 DNA sequences of Tomicus destruens provided by intensive and extensive collection and GenBank entries. We combined phylogeography and regression models to study the role of five environmental predictors at fine scale in the distribution of a local genealogy. The analysis revealed a high genetic diversity, with 52 haplotypes present in Sierra Espuña forest (SE Spain) and 21 haplotypes in the other 14 Spanish populations, all included in the western clade of the Mediterranean phylogeography of the species. We found a micro‐distribution of the species related to altitude and putative niche segregation between lineages associated with the micro‐environmental conditions of their host pine trees. We compared the phylogeographic hypothesis obtained here with the phylogeography obtained integrating our data with all data published elsewhere. Here, we demonstrate a relation between the environmental heterogeneity and the haplotypic diversity at Mediterranean Basin scale. This analysis allows us to support the evolutionary scenario where the phylogeography and current molecular diversity of T. destruens is a consequence of the recolonization from two principal refugia at both extremes of the Mediterranean Basin and, according to our data, we propose that the heterogeneity of habitats allows fixation of the mitochondrial lineages.  相似文献   

13.
The distribution of many species inhabiting northwestern North America has been heavily influenced by the climatic changes during the late Pleistocene. Several studies have suggested that species were restricted to glacial refugia north and/or south of the continental ice sheet front. It is also hypothesized that the coast of northwestern North America could have been a prime location for glacial refugia because of the lowering of the eustatic sea level and the concomitant rise of the continental shelf because of tectonic rebound. Alternatively, some coastal species distributions and demographics may have been unaffected in the long-term by the last glacial maximum (LGM). We tested the glacial refugium hypothesis on an obligate coastal plant species, Carex macrocephala by sampling 600 individuals from 41 populations with 11 nuclear microsatellite loci and the rpL16 plastid intragenic spacer region. The microsatellite data sets suggest a low level of population differentiation with a standardized G 'ST = 0.032 and inbreeding was high with an F  =   0.969. The homogenization of the populations along the coast was supported by a principal coordinate analysis, amova s and samova analyses. Analyses using the rpL16 data set support the results of the microsatellite analyses, with a low F ST of 0.042. Coalescent and mismatch analyses using rpL16 suggest that C. macrocephala has not gone through a significant bottleneck within the past 100 000 years, although a much earlier population expansion was indicated by the mismatch analysis. Carex macrocephala exhibits the characteristics of metapopulation dynamics and on the basis of these results, we concluded that it was not restricted to glacial refugia during the LGM, but that it existed as a large metapopulation.  相似文献   

14.
15.
Freshwater crayfishes represent an incredibly diverse component of temperate aquatic ecosystems. The genus Orconectes (Cambaridae) comprises approximately 17% of total global crayfish diversity and is native to central and eastern North America. Using both Bayesian and parsimony-based phylogenetic hypotheses from complete cytochrome c oxidase subunit I (COI) mtDNA sequence data (1545 bp) along with information on male gonopod shape and species distribution patterns, we examined the evolution of male genital morphology and its potential influence on species co-occurrence. We found that sympatric species exhibited similar male genital morphology more often than expected based on the frequency of genital shapes within the genus. When evolutionary history was incorporated into this analysis, the result was no longer significant, suggesting that species co-occurrence and the associated genital shapes of sympatric congeners cannot be explained solely by interspecific ecological interactions. Our results also do not support the current subgeneric classifications within Orconectes or the monophyly of the genus, both of which have been based previously on male genital morphology.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 1–12.  相似文献   

16.
The aquatic larvae of the family Elmidae (Coleoptera) have been considered unable to swim because they lack swimming setae on their body and legs. We discovered that riffle beetle larvae (Leptelmis gracilis Sharp) are in fact able to swim. After opening the tuft‐like gills on the last abdominal segment they swim by repeatedly bending the abdomen into a U‐shape very quickly and in a wavy manner, while their head and thorax move anteriorly, resulting in a sigmoidal body shape. The flat bodies of L. gracilis larvae could be advantageous for swimming compared to the cylindrical or semicylindrical bodies of larvae in related genera.  相似文献   

17.
对21种帘蛤科贝类线粒体细胞色素c氧化酶亚基Ⅰ(cytochrome c oxidase subunit I,COI)基因核苷酸序列进行了分析,以探讨这一序列在种质鉴定、分子系统发生研究中的应用价值。测序结果表明,所有物种扩增片段长度均为707 bp(含引物),序列A+T含量(62.4%—67.8%)明显高于G+C含量。物种间共有变异位点379个,其中简约信息位点334个;此区段共编码235个氨基酸,种间共有氨基酸变异位点100个。以COI基因片段序列为标记,用中国蛤蜊(Mactra chinensis)作外群,构建了35种帘蛤科贝类(其中14种贝类COI序列从GenBank下载)的系统发生树,结合拓扑结构分析和序列比对分析,结果表明:支持将短文蛤(Meretrix petechinalis)和丽文蛤(M.lusoria)订为文蛤(M.meretrix)的同物异名的观点,建议将丽文蛤和短文蛤订为文蛤的地理亚种;支持将薄片镜蛤(Dosinia corrugata)和D.angulosa订为2个独立种的观点;认为将波纹巴非蛤(Paphia undulata)和织锦巴非蛤(P.textile)订为2个独立种是合适的。COI基因序列含有丰富的遗传信息,适合作为帘蛤科贝类种群遗传结构和系统发生研究的分子标记。  相似文献   

18.
19.
The gene encoding cytochrome c-553 from Desulfovibrio vulgaris (Miyazaki F) was cloned using a synthetic oligodeoxyribonucleotide probe. The nucleotide sequence indicated that cytochrome c-553 was synthesized as a precursor protein with an NH2-terminal signal sequence of 23 residues. In the cloned DNA fragment, there are three other open reading frames whose products have 191, 157, 541 amino acid residues, respectively. The putative ORF-4 product is highly homologous with the cytochrome c oxidase subunit I from various organisms.  相似文献   

20.
Hyles t. tithymali on the Canary Islands has been observed to occur in two larval morphotypes, connected by intermediate forms along a geographical cline from east to west. In this study, it was tested whether this distribution of phenotypes reflects a genealogical division of the population. mtDNA sequence data (COI + II, tRNA-leu) and genomic fingerprints from intersimple sequence repeat (ISSR)-PCR data were used. The sequence data had low variation (max. 0.4%), and phylogenetic analyses did not reveal groups that correlated with the morphotype. The samples did not group according to their island of origin and the most common haplotype was shared among all islands. Although nine haplotypes occurred only on the westernmost islands, the data showed little phylogeographical structure. The population of H. t. tithymali appears to reflect a comparatively rapid and recent colonization event of the Canary Islands. The ISSR-PCR data were very variable and did not reveal patterns corresponding to morphological variation or geographical distribution. Although the two morphs observed may represent the first stage of differentiation between two lineages, the recent origin of H. t. tithymali provided insufficient time for complete lineage sorting of ancestral polymorphism. Hence, the population of Hyles t. tithymali on the Canary Islands appears genetically more homogeneous than that was expected from the phenotypic distribution of the two morphotypes in the population.  相似文献   

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