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1.
The Korean freshwater Corbicula was surveyed genetically by sequencing 614-bp homologous fragment of mitochondrial cytochrome oxidase I subunit. Among a total of 127 individuals collected from 12 Korean freshwater localities we found only two COI haplotypes and these differed by a total of 9 base substitutions. Although the sequence divergence between the two haplotypes is moderate (p = 1.47%), placing the two mitotypic sequences in the context of Asian mtDNA phylogeny reveals that Korean freshwater Corbicula is comprised of two independent freshwater mitochondrial lineages. These results are in serious disagreement with the long-standing conclusions of earlier conchology-based taxonomic work on Korean Corbicula in which a number of species names (a minimum of 10 nominal species) have been used. This indicates that morphological characteristics alone are poor criteria for species-level identification in this group. In addition, our COI dataset shows that there is an extremely low level of genetic variation in Korean freshwater populations, suggesting that these populations have passed through a severe population bottleneck that greatly reduced their genetic variability. Our data also provide new information on the biogeographic distribution of Korean freshwater Corbicula. When haplotypic frequencies were compared, it was evident that the two Korean freshwater mitochondrial lineages have achieved very different distribution ranges: the predominant lineage (FWKR1) is widely distributed in Korean freshwater systems, whereas the minor lineage (FWKR2) is restricted to a relatively narrow range.  相似文献   

2.
Chen SY  Duan ZY  Sha T  Xiangyu J  Wu SF  Zhang YP 《Gene》2006,376(2):216-223
To characterize the origin, genetic diversity, and phylogeographic structure of Chinese domestic sheep, we here analyzed a 531-bp fragment of mtDNA control region of 449 Chinese autochthonous sheep from 19 breeds/populations from 13 geographic regions, together with previously reported 44 sequences from Chinese indigenous sheep. Phylogenetic analysis showed that all three previously defined lineages A, B, and C were found in all sampled Chinese sheep populations, except for the absence of lineage C in four populations. Network profiles revealed that the lineages B and C displayed a star-like phylogeny with the founder haplotype in the centre, and that two star-like subclades with two founder haplotypes were identified in lineage A. The pattern of genetic variation in lineage A, together with the divergence time between the two central founder haplotypes suggested that two independent domestication events have occurred in sheep lineage A. Considerable mitochondrial diversity was observed in Chinese sheep. Weak structuring was observed either among Chinese indigenous sheep populations or between Asian and European sheep and this can be attributable to long-term strong gene flow induced by historical human movements. The high levels of intra-population diversity in Chinese sheep and the weak phylogeographic structuring indicated three geographically independent domestication events have occurred and the domestication place was not only confined to the Near East, but also occurred in other regions.  相似文献   

3.
An analysis of mitochondrial DNA sequence variation in 172 three-spined sticklebacks (Gasterosteus aculeatus) sampled across the European distribution range revealed three major evolutionary lineages occupying relatively large and separate geographic areas. The trans-Atlantic lineage comprised of populations spanning from the East Coast of USA to the continental Europe and was basal group to the other European lineages in the phylogeny. The European lineage included populations located in the Western and Eastern Europe, British Isles, Scandinavia as well as some parts of the Mediterranean region. The third lineage was specific to the Black Sea drainages. The within lineage structure was characterized by significant excess of low frequency haplotypes and star-like mtDNA genealogies, which suggest a recent population expansions to the formerly glaciated marine and freshwater environments. A coalescent-based method dated the splits between the major lineages to have occurred during the Saalian and Weichselian glaciations in the late Pleistocene, depending on the molecular clock calibration. The coalescent simulations further indicate high degree of genetic diversity within the lineages and a substantial increase in the genetic diversity in the European lineage relative to the ancestral level. In addition to the three major lineages, the freshwater populations in R. Neretva and L. Skadar in the Adriatic Sea coast region harboured unique and highly divergent haplotypes suggesting long independent histories of these populations. Evidence from mtDNA analyses suggests that these populations deserve a status of an evolutionary significant unit.  相似文献   

4.
Analyses of mitochondrial (mt) DNA and microsatellite variation were carried out to examine the relationships between 10 freshwater populations of three-spined sticklebacks Gasterosteus aculeatus along the eastern coast of the Adriatic Sea. Partial sequences of the mtDNA control region and cytochrome b gene, in addition to 15 microsatellite loci, were used to analyse populations from four isolated river catchments. Results uncovered an Adriatic lineage that was clearly divergent from the European lineage, and confirmed that the most divergent and ancient populations are located within the Adriatic lineage as compared with other European populations. Two northern Adriatic populations formed independent clades within the European mitochondrial lineage, suggesting different colonization histories of the different Adriatic populations. Nuclear marker analyses also indicated deep divergence between Adriatic and European populations, albeit with some discordance between the mtDNA phylogeny of the northern Adriatic populations, further highlighting the strong differentiation among the Adriatic populations. The southern populations within the Adriatic lineage were further organized into distinct clades corresponding to respective river catchments and sub-clades corresponding to river tributaries, reflecting a high degree of population structuring within a small geographic region, concurrent with suggestions of existence of several microrefugia within the Balkan Peninsula. The highly divergent clades and haplotypes unique to the southern Adriatic populations further suggest, in accordance with an earlier, more limited survey, that southern Adriatic populations represent an important reservoir for ancient genetic diversity of G. aculeatus.  相似文献   

5.
Chen S  Fan B  Liu B  Yu M  Zhao S  Zhu M  Xiong T  Li K 《Biochemical genetics》2006,44(3-4):87-97
Phylogenetic relationships among and genetic variability within 13 Chinese indigenous goat breeds and Boer goat were analyzed using cytochrome b gene sequences. There were 44 variable sites found in a 642 bp sequence, and 46 Cyt b haplotypes were subsequently defined. The phylogeny analysis of haplotypes in combination with goat Cyt b sequences from GenBank shows that Chinese goats are obviously separated from wild goats and might come from Capra aegagrus. Further analysis indicated that indigenous Chinese goats might descend from at least two lineages; most of the individuals analyzed could be classified into lineage A as defined by Luikart, but five other goats were of uncertain lineage. The Tibet plateau is a possible place of origin for Chinese goats. The neighbor-joining tree based on pairwise differences among populations shows that most Tibetan goats, except the Middle Tibet type, cluster closely with North China goats, and then with South China goats. This result confirms that differences in genetic structure exist among goats in different geographic locations. Nucleotide diversity varied among populations. Tibet and North China goats had higher genetic diversity than South China goats. The fixation index (F st=87.72%) suggested that most of the total genetic variation was due to variation within populations. In addition, the results indicate that Cyt b gene sequence information alone might not be enough for phylogeny analysis among breeds within species, as shown by fewer polymorphic sites and lower bootstrap values on the neighbor-joining tree.  相似文献   

6.
The Manchurian trout, Brachymystax lenok tsinlingensis (family: Salmonidae), is a cold freshwater fish endemic to Northeast Asia. South Korean populations of this species, which comprise its southern range limit, have recently decreased markedly in size and are now becoming critically endangered. We assessed the current population status of this species in South Korea by estimating the levels of genetic diversity and genetic structure of five natural and four restored populations using mitochondrial DNA (mtDNA) control region sequences and eight nuclear microsatellite loci. Levels of within-population genetic diversity were low, suggesting that past effective population sizes (N e) have been small. Each population had one or a maximum of two mtDNA haplotypes. Microsatellite allelic richness (AR) was significantly higher for natural populations (mean AR?=?3.51; 95% confidence interval, 3.00–4.03) than for restored populations (mean AR?=?2.61; 2.38–2.98). South Korean populations were significantly genetically isolated from one another, with private mtDNA haplotypes and microsatellite alleles, suggesting that limited gene flow has been occurring among populations. A mtDNA phylogeny revealed that South Korean lineages were more closely related to those of China than to those of North Korea and Russia. Overall, we suggest that future restoration efforts aimed at South Korean populations should consider the genetic characteristics reported here, which should help to fulfil effective conservation strategies for this highly cherished species. Our results will inform other conservation efforts, including assisted migration of freshwater fish populations at the equatorial end of the geographical range limit of the species.  相似文献   

7.
In order to facilitate the on-going cattle conservation and improvement programs in Korea, we examined genetic relationships among East Asian cattle, focusing on Korean native cattle, using complete mitochondrial DNA control region sequences. In total, 67 haplotypes were discriminated by 97 variable sites in East Asian cattle. Of the variable sites, 35 represented singleton variable sites and 62 were parsimony informative sites. For Korean cattle, 30 haplotypes were discriminated by 40 variable sites. The variable sites identified in this study correspond to transition or transversion point mutations. Inter-populations genetic distance varied from 0.004 to 0.052 for East Asian cattle populations. The genetic divergence observed between Korean Brown and Jeju Black (0.004) was among the lowest. The Mongolian cattle were slightly divergent from other East Asian cattle populations studied. The network analysis uncovered that Jeju Black and Yunbian samples represented the possible ancestral Haplotype within T3 Bos taurus main lineage. Thus, we hypothesized that the Jeju and Yunbian cattle may represent one of the original native North East Asian cattle in the region.  相似文献   

8.
Abstract The Mediterranean species complex of Senecio serves to illustrate evolutionary processes that are likely to confound phylogenetic inference, including rapid diversification, gene tree‐species tree discordance, reticulation, interlocus concerted evolution, and lack of complete lineage sorting. Phylogeographic patterns of chloroplast DNA (cpDNA) haplotype variation were studied by sampling 156 populations (502 individuals) across 18 species of the complex, and a species phylogeny was reconstructed based on sequences from the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA. For a subset of species, randomly amplified polymorphic DNAs (RAPDs) provided reference points for comparison with the cpDNA and ITS datasets. Two classes of cpDNA haplotypes were identified, with each predominating in certain parts of the Mediterranean region. However, with the exception of S. gallicus, intraspecific phylogeographic structure is limited, and only a few haplotypes detected were species‐specific. Nuclear sequence divergence is low, and several unresolved phylogenetic groupings are suggestive of near simultaneous diversification. Two well‐supported ITS clades contain the majority of species, amongst which there is a pronounced sharing of cpDNA haplotypes. Our data are not capable of diagnosing the relative impact of reticulation versus insufficient lineage sorting for the entire complex. However, there is firm evidence that S. flavus subsp. breviflorus and S. rupestris have acquired cpDNA haplotypes and ITS sequences from co‐occurring species by reticulation. In contrast, insufficient lineage sorting is a viable hypothesis for cpDNA haplotypes shared between S. gallicus and its close relatives. We estimated the minimum coalescent times for these haplotypes by utilizing the inferred species phylogeny and associated divergence times. Our data suggest that ancestral cpDNA polymorphisms may have survived for ca. 0.4–1.0 million years, depending on molecular clock calibrations.  相似文献   

9.
The Northeast area of China is a cross region between East Asia and Siberia. Although five populations from this area have been studied in maternal lineage, little is known about the genetics of other populations. In this study, forty-seven Manchu individuals were analyzed using a mitochondrial DNA marker, and fourteen mitochondrial DNA haplogroups, the representative haplogroups of east Eurasian, were identified. All analyses showed that Manchu were close to the neighboring populations such as Mongolian, Korean and northern Han Chinese, and were far from the other populations who lived in the cradle of Manchu, suggesting that the Manchu integrated gradually with natives following its southward migration.  相似文献   

10.
Population Genetics and Phylogeography of Bufo gargarizans in China   总被引:1,自引:0,他引:1  
Hu YL  Wu XB  Jiang ZG  Yan P  Su X  Cao SY 《Biochemical genetics》2007,45(9-10):697-711
The Chinese toad Bufo gargarizans has an extensive range, covering nearly all of China. This study addresses the population genetic structure of this toad and the relation to geographic location. Partial sequences of the mtDNA control region were obtained from 14 populations, 29 haplotypes were defined, and 73 variable sites were found, including 66 parsimony informative sites. All population genetic analyses indicated no clear geographic pattern in the distribution of haplotypes. The genetic divergence between the populations was significant. Phylogeographic analyses suggested that past fragmentation and/or long-distance colonization seemed to have shaped the present-day distribution of the haplotypes of B. gargarizans.  相似文献   

11.
Liu Y  Hou M  Wu K 《Environmental entomology》2010,39(4):1344-1351
The pink bollworm Pectinophora gossypiella is an invasive pest insect that has successfully established populations in many cotton growing regions around the world. In this study, the genetic diversity and population structure of Chinese populations of P. gossypiella were evaluated using mitochondrial DNA sequence data (COII and Nad4). For comparison, individuals of Pakistan and America were also sequenced at the same two mtDNA regions. Extremely low genetic variation was observed in the two mitochondrial regions among all populations examined. Most of the populations harbored only one to two haplotypes. Although the Nad4 region showed relatively high haplotype diversity and nucleotide variation, ranging from 0.363 to 0.591 and from 0.00078 to 0.00140, respectively, there were only three haplotypes observed in this region. COII and Nad4 haplotype networks shaved one or two common haplotype(s) forming the center of a star-shaped phylogeny. Pairwise tests showed that most of the populations were not significantly differentiated from each other. The Chinese populations were differentiated from the Pakistani and American populations in the Nad4 region. The low level of population genetic variation of P. gossypiella is attributed to invasion bottlenecks, which may have been subsequently strengthened by its nonmigratory biology and the mosaic pattern of agricultural activities.  相似文献   

12.
Mitochondrial DNA variation in Nicobarese Islanders.   总被引:4,自引:0,他引:4  
The aboriginal populations living in the Nicobar Islands are hypothesized to be descendants of people who were part of early human dispersals into Southeast Asia. However, analyses of ethnographic histories, languages, morphometric data, and protein polymorphisms have not yet resolved which worldwide populations are most closely related to the Nicobarese. Thus, to explore the origins and affinities of the Nicobar Islanders, we analyzed mitochondrial DNA (mtDNA) hypervariable region 1 sequence data from 33 Nicobarese Islanders and compared their mtDNA haplotypes to those of neighboring East Asians, mainland and island Southeast Asians, Indians, Australian aborigines, Pacific Islanders, and Africans. Unique Nicobarese mtDNA haplotypes, including five Nicobarese mtDNA haplotypes linked to the COII/tRNA(Lys) 9-bp deletion, are most closely related to mtDNA haplotypes from mainland Southeast Asian Mon-Kmer-speaking populations (e.g., Cambodians). Thus, the dispersal of southern Chinese into mainland Southeast Asia may have included a westward expansion and colonization of the islands of the Andaman Sea.  相似文献   

13.
Phylogenetic analyses of complete mitochondrial cytochrome b sequences support the monophyly of pocket gopher (Thomomys bottae) populations from the 1000 km length of the Baja California peninsula of Mexico, relative to other geographical segments of the species range in western North America. The Baja California peninsula is an area that encompasses considerable ecomorphological and infraspecific diversity within this pocket gopher species. However, detailed population analyses encompassing 35 localities distributed over the southern half of the peninsula reveal only trivial phylogeographical structure. Rather, most of the 72 unique 500-base pair haplotypes examined from 142 individuals is restricted to single populations, although a few haplotypes are shared broadly across geography. Individual populations are typically comprised of haplotype sets from different branches in a network of relationships. Analysis of molecular variance (amova) indicates that approximately half of the total pool of variation is contained among individuals within local populations, and that only about 25% can be explained by the regional subdivisions of current subspecies distributions or physiographic realms. A hypothesized historical vicariant event that has been causally linked to the phylogeographical structure of other, codistributed species has had little influence on these pocket gopher populations, explaining only 13% of the total variation. The temporal depth, estimated by coalescence parameters, of the haplotype lineage in Baja California is relatively recent, approximately 300,000 generations; both the mismatch distribution of pairwise comparisons and a significantly positive exponential growth estimate support a recent history of expanding populations; but current, or recent past, migration estimates have remained small, are largely unidirectional from north to south, and weak isolation by distance is present. All data suggest that pocket gophers have relatively recently invaded the southern half of peninsular Baja California, with the genetic signature of expansion still evident but with sufficient time having lapsed to result in a weak isolation by distance pattern. The geographical assemblage of sampled populations thus appears as a meta-population, with limited gene flow contrasting with random haplotype loss due to drift in small, localized populations.  相似文献   

14.
To study the phylogeography of the ground beetle Carabus yamato in Japan, we compared 1,020-bp sequences of the mitochondrial NADH dehydrogenase subunit 5 (ND5) gene from 373 specimens from 37 localities with those of three parapatric species (C. albrechti, C. kimurai, and C. japonicus) that might share mitochondrial lineages with C. yamato through introgressive hybridization. We found 81 haplotypes from C. yamato. Of these, 17 haplotypes were considered to be of an introgressed lineage from C. albrechti, based on the phylogeny and geographic distribution. In addition, one haplotype of C. kimurai was likely an introgressant from C. yamato. Putative introgression events among the four species were restricted to these two directional cases. We analyzed the phylogeography of C. yamato using nested clade phylogeographical analysis and population genetic parameters. The mitochondrial lineages of C. yamato were estimated to have diverged no more than approximately 1.12 million years ago, implying that the estimated historical events occurred after the Early Pleistocene. Carabus yamato was inferred to have experienced a contraction of its distribution range, followed by recent range expansion. Populations in the western and eastern regions, segregated by Ise Bay and the Nobi and Okazaki Plains, diverged in the mitochondrial clades. The northern and most western populations possessed one clade only (except an introgressed lineage), whereas eastern and some southwestern populations possessed several diverged clades, which were considered to be ancestral; these populations may have been associated with refugia during glacial periods.  相似文献   

15.
Lloyd BD 《Molecular ecology》2003,12(7):1895-1911
Short-tailed bats Mystacina tuberculata were widespread throughout the forest that dominated prehuman New Zealand, but extensive deforestation has restricted them to scattered populations in forest fragments. In a previous study, the species' intraspecific phylogeny was investigated using multiple mitochondrial gene sequences. Six phylogroups were identified with estimated divergences of 0.93-0.68 Ma. In the current study, the phylogeographical structure and demographic history of the phylogroups were investigated using control region sequences modified by removing homoplasic sites. Phylogeographical structure in the North Island was generally consistent with an isolation-by-distance dispersal model. Coalescent-based analyses (i.e. mismatch distributions, skyline plots, lineage dispersal analysis and nested clade analysis) indicated that the three phylogroups found in central and southern North Island expanded before the last glacial maximum, presumably during interstadials when Nothofagus forest was most extensive. Genetic structure within a central North Island hybrid zone was consistent with range expansion from separate refugia following reforestation after catastrophic volcanic eruptions. Phylogeographical structure in the South Island was consistent with southern populations originating during rapid southward range expansion from refugia in northern South Island following postglacial reforestation of the South Island 10-9 kya.  相似文献   

16.
The dung beetle, Copris tripartitus (Coleoptera: Scarabaeidae), is an endangered insect in Korea. In order to establish a conservation strategy, a preliminary investigation on the genetic diversity of Korean populations was performed using mitochondrial COI (658 bp), CytB (433 bp), and nuclear ITS2 (411 nucleotide positions). Sequencing of 69 individuals collected from five localities showed substantially higher variability (5.02% for COI, 4.62% for CytB, and 8.03% for ITS2). The resulting networks for mitochondrial DNA (mtDNA) haplotypes exhibited two star‐like phylogenies, which might indicate that Korean populations have recently expended from two small populations. The ITS2 network, which was presented in the form of a star‐like phylogeny, confirmed that a recent population expansion occurred. Considering the high genetic diversity and gene flow in C. tripartitus populations, one issue regarding conservation seems to be the recovery of previous habitats.  相似文献   

17.
Population declines and extinctions of amphibians have been attributed to the chytrid fungus Batrachochytrium dendrobatidis (Bd), especially one globally emerging recombinant lineage (‘Bd‐GPL’). We used PCR assays that target the ribosomal internal transcribed spacer region (ITS) of Bd to determine the prevalence and genetic diversity of Bd in South Korea, where Bd is widely distributed but is not known to cause morbidity or mortality in wild populations. We isolated Korean Bd strains from native amphibians with low infection loads and compared them to known worldwide Bd strains using 19 polymorphic SNP and microsatellite loci. Bd prevalence ranged between 12.5 and 48.0%, in 11 of 17 native Korean species, and 24.7% in the introduced bullfrog Lithobates catesbeianus. Based on ITS sequence variation, 47 of the 50 identified Korean haplotypes formed a group closely associated with a native Brazilian Bd lineage, separated from the Bd‐GPL lineage. However, multilocus genotyping of three Korean Bd isolates revealed strong divergence from both Bd‐GPL and the native Brazilian Bd lineages. Thus, the ITS region resolves genotypes that diverge from Bd‐GPL but otherwise generates ambiguous phylogenies. Our results point to the presence of highly diversified endemic strains of Bd across Asian amphibian species. The rarity of Bd‐GPL‐associated haplotypes suggests that either this lineage was introduced into Korea only recently or Bd‐GPL has been outcompeted by native Bd strains. Our results highlight the need to consider possible complex interactions among native Bd lineages, Bd‐GPL and their associated amphibian hosts when assessing the spread and impact of Bd‐GPL on worldwide amphibian populations.  相似文献   

18.
《Mammalian Biology》2014,79(5):287-296
The Eurasian beaver (Castor fiber) represents an uncommon example of an endangered species in which the restoration programs proved a spectacular success and led to enormous spatial and demographic expansion. Documented reintroduction of beavers in Poland has been conducted using animals of the eastern European origin, most likely derived from the eastern mtDNA lineage. However demographic and spatial expansion of beavers from Germany, which represent the western lineage, may have led to admixture of these two genetically distinct entities in Poland. We detected significant genetic differentiation between the populations from W and NE Poland both in mitochondrial DNA control region and microsatellites, but also substantial admixture including apparent first-generation migrants between regions. Our results indicate that beavers from the western mtDNA lineage have contributed considerably to the Polish population, particularly in W Poland. As there have been no adequately documented translocations of beavers from the western European populations to Poland, the observed situation appears to result from natural migration or range expansion from the west. In contrast to previous findings we detected a substantial diversity in mtDNA control region, which indicates that either the variation in relict populations has been underestimated, or that additional relict beaver populations survived at the end of the 19th century in Poland and Germany as indicated by considerable similarity of ancient and extant mtDNA haplotypes. The implications of our findings for beaver conservation and management are discussed.  相似文献   

19.
Using mitochondrial DNA control region (mtDNA CR) sequence data the present study evaluates the genetic status of the wild populations of channel catfish, Ictalurus punctatus, in North America. A total of 584 individuals representing 56 drainages across its distributional range in the United States were collected. There were 105 mtDNA CR haplotypes defined by 51 variable sites. Phylogenetic analyses have revealed the existence of six distinct matrilineal genetic lineages of channel catfish in the United States. Four of these lineages were restricted to southeast Gulf Coast, a region that never glaciated during the Pleistocene. While samples from the Mississippi river and its tributaries represent a single genetic lineage, samples from the southeast Atlantic coastal plain drainages formed a unique lineage. Each lineage should be regarded as an evolutionarily significant unit/management unit and therefore separate management and conservation strategies should be undertaken in order to conserve the genetic resources.  相似文献   

20.
Pleistocene sea-level fluctuations profoundly changed landmass configurations around northern Australia. The cyclic emergence of the Torres Strait land bridge and concomitant shifts in the distribution of shallow-water marine habitats repeatedly sundered east and west coast populations. These biogeographical perturbations invoke three possible scenarios regarding the directions of interglacial range expansion: west to east, east to west, or bidirectional. We evaluated these scenarios for the olive sea snake, Aipysurus laevis, by exploring its genetic structure around northern Australia based on 354 individuals from 14 locations in three regions (Western Australia, WA; Gulf of Carpentaria, GoC; Great Barrier Reef, GBR). A 726-bp fragment of the mitochondrial DNA ND4 region revealed 41 variable sites and 38 haplotypes, with no shared haplotypes among the three regions. Population genetic structure was strong overall, phiST=0.78, P<0.001, and coalescent analyses revealed no migration between regions. Genetic diversity was low in the GBR and GoC and the genetic signatures of these regions indicated range or population expansions consistent with their recent marine transgressions around 7000 years ago. By contrast, genetic diversity on most WA reefs was higher and there were no signals of recent expansion events on these reefs. Phylogenetic analyses indicated that GBR and GoC haplotypes were derived from WA haplotypes; however, statistical parsimony suggested that recent range expansion in the GBR-GoC probably occurred from east coast populations, possibly in the Coral Sea. Levels of contemporary female-mediated gene flow varied within regions and reflected potential connectivity among populations afforded by the different regional habitat types.  相似文献   

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