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1.
To explore phylogenetic relationships among glyptosternoid fishes, we determined nucleotide sequences of the complete mitochondrial cytochrome b gene region (1138 base pair). Thirteen species of glyptosternoid fishes and six species of non-glyptosternoids represent 10 sisorid genera were examined. Molecular phylogenetic trees were constructed using the maximum parsimony, minimum evolution, maximum likelihood, and Bayesian methods. Bayesian and maximum likelihood analyses support the monophyly of glyptosternoids, but our hypothesis of internal relationships differs from previous hypothesis. Results indicated that glyptosternoid is a monophyletic group and genera Glyptosternum and Exostoma are two basal species having a primitive position among it. Genera Euchiloglanis and Pareuchiloglanis form a sister-group. Then they form a sister-group with Pseudexostoma plus Oreoglanis. Our result also found that Pareuchiloglanis anteanalis might be considered as the synonyms of Parechiloglanis sinensis, and genus Euchiloglanis might have only one valid species, Euchiloglanis davidi.  相似文献   

2.
A phylogeny of the species of the nase genus Chondrostoma was constructed from a complete mitochondrial cytochrome b gene (1140 bp). Molecular phylogeny was used to revise the current systematics of this group, and to infer a biogeographical model of the Mediterranean area during the Cenozoic period. We confirmed the monophyly of the genus Chondrostoma, and defined seven different lineages within it: Polylepis, Arcasii, Lemmingii, Toxostoma, Nasus, C. genei, and C. soetta. The separation of main lineages within Chondrostoma occurred in the Middle-Upper Miocene, approximately 11 million years ago, while the greatest species radiation took place in the Pliocene close to the time the current drainages system were created. It is unlikely that this genus experienced an extensive dispersal during the Messinian, in the Lago-Mare Phase. Given the level of current knowledge, a biogeographical model constructed on the basis of vicariant events seems more realistic than does a dispersalist model.  相似文献   

3.
The Alcidae is a unique assemblage of Northern Hemisphere seabirds that forage by "flying" underwater. Despite obvious affinities among the species, their evolutionary relationships are unclear. We analyzed nucleotide sequences of 1,045 base pairs of the mitochondrial cytochrome b gene and allelic profiles for 37 allozyme loci in all 22 extant species. Trees were constructed on independent and combined data sets using maximum parsimony and distance methods that correct for superimposed changes. Alternative methods of analysis produced only minor differences in relationships that were supported strongly by bootstrapping or standard error tests. Combining sequence and allozyme data into a single analysis provided the greatest number of relationships receiving strong support. Addition of published morphological and ecological data did not improve support for any additional relationship. All analyses grouped species into six distinct lineages: (1) the dovekie (Alle alle) and auks, (2) guillemots, (3) brachyramphine murrelets, (4) synthliboramphine murrelets, (5) true auklets, and (6) the rhinoceros auklet (Cerorhinca monocerata) and puffins. The two murres (genus Uria) were sister taxa, and the black guillemot (Cepphus grylle) was basal to the other guillemots. The Asian subspecies of the marbled murrelet (Brachyramphus marmoratus perdix) was the most divergent brachyramphine murrelet, and two distinct lineages occurred within the synthliboramphine murrelets. Cassin's auklet (Ptychoramphus aleuticus) and the rhinoceros auklet were basal to the other auklets and puffins, respectively, and the Atlantic (Fratercula arctica) and horned (Fratercula corniculata) puffins were sister taxa. Several relationships among tribes, among the dovekie and auks, and among the auklets could not be resolved but resembled "star" phylogenies indicative of adaptive radiations at different depths within the trees.   相似文献   

4.
The presence of Pneumocystis organisms was detected by nested-PCR at mitochondrial large subunit (mtLSU) rRNA gene in 23 respiratory samples from Asian macaques representing two species: Macaca mulatta and M. fascicularis. A very high level of sequence heterogeneity was detected with 18 original sequence types. Two genetic groups of Pneumocystis could be distinguished from the samples. Within each group, the extent of genetic divergence was low (2.5+/-1.4% in group 1 and 2.3+/-1.7% in group 2). Genetic divergences were systematically higher when macaque-derived sequence types were compared with Pneumocystis mtLSU sequences from other primate species (from 5.3+/-2.7% to 19.3+/-3.0%). The two macaque-derived groups may be considered as distinct Pneumocystis species. Surprisingly, these Pneumocystis species were recovered from both M. mulatta and M. fascicularis suggesting that host-species restriction may not systematically occur in the genus Pneumocystis. Alternatively, these observations question about the species concept in macaques.  相似文献   

5.
Voles of the genus Microtus represent one of the most speciose mammalian genera in the Holarctic. We established a molecular phylogeny for Microtus to resolve contentious issues of systematic relationships and evolutionary history in this genus. A total of 81 specimens representing ten Microtus species endemic to Europe as well as eight Eurasian, six Asian and one Holarctic species were sequenced for the entire cytochrome b gene (1140 bp). A further 25 sequences were retrieved from GenBank, providing data on an additional 23, mainly Nearctic, Microtus species. Phylogenetic analysis of these 48 species generated four well-supported monophyletic lineages. The genus Chionomys, snow voles, formed a distinct and well-supported lineage separate from the genus Microtus. The subgenus Microtus formed the strongest supported lineage with two sublineages displaying a close relationship between the arvalis species group (common voles) and the socialis species group (social voles). Monophyly of the Palearctic pitymyid voles, subgenus Terricola, was supported, and this subgenus was also subdivided into two monophyletic species groups. Together, these groupings clarify long-standing taxonomic uncertainties in Microtus. In addition, the "Asian" and the Nearctic lineages reported previously were identified although the latter group was not supported. However, relationships among the main Microtus branches were not resolved, suggesting a rapid and potentially simultaneous radiation of a widespread ancestor early in the history of the genus. This and subsequent radiations discernible in the cytochrome b phylogeny, show the considerable potential of Microtus for analysis of historical and ecological determinants of speciation in small mammals. It is evident that speciation is an ongoing process in the genus and that the molecular data provides a vital insight into current species limits as well as cladogenic events of the past.  相似文献   

6.
The taxonomy of the North American big-eared bats, genus Corynorhinus, was revised by Handley [Handley, C.O., 1959. A revision of the American bats of the genera Euderma and Plecotus. Proc. U.S. Nat. Mus. 110, 95-246] using a morphological systematics approach. Handley employed 17 morphological characters and identified only four characters that reliably differentiated the three species he recognized, C. townsendii, C. rafinesquii, and C. mexicanus. All three species have been shown to lead relatively sedentary lives and have a wing morphology that limits long-distance dispersal. Further, populations of two species, C. townsendii and C. rafinesquii, are considered to be declining. Handley [Handley, C.O., 1959. A revision of the American bats of the genera Euderma and Plecotus. Proc. U.S. Nat. Mus. 110, 95-246] recognized five subspecies of C. townsendii (C. t. australis, C. t. ingens, C. t. pallescens, C. t. townsendii, and C. t. virginianus) and two of C. rafinesquii (C. r. rafinesquii and C. r. macrotis). Two C. townsendii subspecies, C. t. ingens and C. t. virginianus, are listed as endangered under the Endangered Species Act. These facts and the lack of a thorough molecular systematic examination of this genus were the impetus for this study. Using mitochondrial and nuclear intron DNA sequences, a molecular phylogeny was inferred. The combined DNA phylogeny supports Handley's [Handley, C.O., 1959. A revision of the American bats of the genera Euderma and Plecotus. Proc. U. S. Nat. Mus. 110, 95-246] designation of three species. Further the endangered subspecies, C. t. ingens and C. t. virginianus are corroborated, as were the monophyly of the other subspecies. However, the geographical ranges of two of these subspecies, C. t. pallescens and C. t. townsendii, are revised based on biogeographic distributions as understood from our results. Estimates of timing of divergences indicate that the three species, C. townsendii, C. rafinesquii, and C. mexicanus may have diverged before Pleistocene climatic oscillations began, and therefore their cladogenesis was not the result of those processes. However, subspecific divergences within C. townsendii appear to have occurred during and been driven largely by the climatic processes of the Pleistocene Epoch. We propose new hypotheses of dispersal scenarios that may have led to the current biogeography of these lineages.  相似文献   

7.
The burbot (Lota lota Linnaeus, 1758) is the only freshwater species from the cod family. Various taxonomic hypotheses were tested against molecular data by sequencing the mitochondrial cytochrome b locus of 120 burbot from 41 populations together with the related species Molva molva (ling) and Brosme brosme (tusk), which represented the other Lotinae genera. Within the genus Lota two distinct phylogroups were observed: one in North America south of the Great Slave Lakes (Lota lota maculosa) and one in Eurasia and the remainder of the Nearctic region (Lota lota lota). The burbot lineage separated 10 Myr BP from the other Lotinae, while the genetic variation within burbot appeared to be approximately 1 Myr old. However, fossil evidence suggested that burbot already existed in the Early Pliocene in Europe, from were it probably colonized North America in the Early Pleistocene. While Nearctic burbot survived climatic oscillations and diverged in several refugia, the Eurasian form became extinct or was reduced to a very small population. In the Late Pleistocene the species recolonized the Palearctic region to establish its present distribution range.  相似文献   

8.
9.
Details of the phylogenetic relationships among tetrahymenine ciliates remain unresolved despite a rich history of investigation with nuclear gene sequences and other characters. We examined all available species of Tetrahymena and three other tetrahymenine ciliates, and inferred their phylogenetic relationships using nearly complete mitochondrial cytochrome c oxidase subunit 1 (cox1) and small subunit (SSU) rRNA gene sequences. The inferred phylogenies showed the genus Tetrahymena to be monophyletic. The three “classical” morphology-and-ecology-based groupings are paraphyletic. The SSUrRNA phylogeny confirmed the previously established australis and borealis groupings, and nine ribosets. However, these nine ribosets were not well supported. Using cox1 gene, the deduced phylogenies based on this gene revealed 12 well supported groupings, called coxisets, which mostly corresponded to the nine ribosets. This study demonstrated the utility of cox1 for resolving the recent phylogeny of Tetrahymena, whereas the SSU rRNA gene provided resolution of deeper phylogenetic relationships within the genus.  相似文献   

10.
We reconstructed phylogenetic relationships of the family Badidae using both mitochondrial and nuclear nucleotide sequence data to address badid systematics and to evaluate the role of vicariant speciation on their evolution and current distribution. Phy-logenetic hypotheses were derived from complete cytochrome b (1,140 base pairs) sequences of 33 individuals representing 13 badid species, and using three species of Nandidae as outgroups. Additionally, we sequenced the nuclear RAG1 (1,473 base pairs) and Tmo-4C4 (511 base pairs) genes from each of the badid species and one representative of the outgroup. Our molecular data provide the first phylogenetic hypothesis of badid intrarelationships. Analysis of the mitochondrial and nuclear nucleotide sequence data sets resulted in well-supported trees, indicating a basal split between the genera Dario and Badis, and further supporting the division of the genus Badis into five species groups as suggested by a previous taxonomic revision of the Badidae. Within the genus Badis, mitochondrial and nuclear phylogenies differed in the relative position of B. kyar. We also used our molecular phylogeny to test a vicariant speciation hypothesis derived from geological evidence of large-scale changes in drainage patterns in the Miocene affecting the Irrawaddy- and Tsangpo-Brahmaputra drainages, in the southeastern Himalaya. Within both genera, Badis and Dario, we observed a divergence into Irrawaddy- and Tsangpo-Brahmaputra clades. Using a cytb substitution rate of 8.2 x 10(-9) (substitutions x base pair(-1) x year(-1), we tentatively date this vicariant event at the Oligocene-Miocene boundary (19-24Myr). It is concordant with a hypothesized paleo connection of the Tsangpo river with the Irrawaddy drainage that was most likely interrupted during Miocene orogenic events through tectonic uplifts in eastern Tibet. Our data, therefore, indicate a substantial role of vicariant-based speciation shaping the current distribution patterns of badids.  相似文献   

11.
The evolutionary affinities within and among many groups of nine-primaried oscines remain unresolved. One such group is Sporophila, a large genus of New World tanager-finches. Our study focused particularly on clarifying the relationship between this genus and a closely related one, Oryzoborus, and on examining the phylogenetic affinities of the "capuchinos," a group of 11 Sporophila species that share a similar male plumage coloration pattern. Our phylogenetic analyses, based on 498 bp of mitochondrial DNA sequence, indicated that: (1) Oryzoborus is embedded within a well-supported clade containing all Sporophila species, which strongly suggests that both genera should be merged, (2) the species of capuchinos comprise a monophyletic group, implying that the plumage patterns common to all probably arose only once, and (3) the capuchinos clade is comprised of two sub-clades, one including two species that are distributed in northern South America and the other one containing eight species that are present south of the Amazon River. Mean sequence divergence among the southern capuchinos species was extremely low, suggesting a rapid radiation within the last half-million years that may be related to the high level of sexual selection present in the genus and might have been promoted by marine ingressions and egressions that occurred in some southern coastal regions of South America in the Late Pleistocene.  相似文献   

12.
To investigate the genetic diversity between the populations of woolly flying squirrels (Eupetaurus) from the eastern and western extremes of the Himalayas, partial mitochondrial cytochrome b gene sequences (390-810 bp) that were determined from the museum specimens were analyzed using maximum parsimony (MP) and maximum likelihood (ML) methods. The molecular data reveal that the two specimens that were collected in northwestern Yunnan (China) are members of the genus Eupetaurus. Reconstructed phylogenetic relationships show that the populations of Eupetaurus in the eastern and western extremes of the Himalayas are two distinct species with significant genetic differences (12%) and diverged about 10.8 million years ago. Eupetaurus is significantly different from Petaurista and Pteromys. The level of estimated pairwise-sequence divergence observed between Eupetaurus and Petaurista or Pteromys is greater than that observed between Eupetaurus and Trogopterus, Belomys, Glaucomys, or Hylopetes. Considering the divergence time of the two Eupetaurus groups, the glaciations and the uplift of the Himalayas and Qinghai-Tibet plateau during the Pliocene-Pleistocene period might be the major factors affecting the present distribution of Eupetaurus along the Himalayas.  相似文献   

13.
The genus Phrynosoma includes 13 species of North American lizards characterized by unique and highly derived morphologies and ecologies. Understanding interspecific relationships within this genus is essential for testing hypotheses about character evolution in this group. We analyzed mitochondrial ND4 and cytochrome b gene sequence data from all species of Phrynosoma in conjunction with a previously published dataset including 12S and 16S rRNA gene sequences and morphological characters. We used multiple phylogenetic methods and diagnostic tests for data combinability and taxonomic congruence to investigate the data in separate and combined analyses. Separate data partitions resulted in several well-supported lineages, but taxonomic congruence was lacking between topologies from separate and combined analyses. Partitioned Bremer support analyses also reveals conflict between data partitions in certain tree regions. When taxa associated with well-supported clades were removed from analyses, phylogenetic signal was lost. Combined, our results initially suggest conflict between data partitions, but further tests show the data are only appropriate for phylogenetic reconstruction of those parts of the topology that were well resolved. Nonetheless, our data analyses reveal five well-supported clades: (1) Phrynosoma ditmarsi and Phrynosoma hernandesi, (2) P. ditmarsi, P. hernandesi, and Phrynosoma douglasii, (3) P. ditmarsi, P. hernandesi, P. douglasii, and Phrynosoma orbiculare, (4) Phrynosoma mcallii and Phrynosoma platyrhinos, and (5) Phrynosoma braconnieri and Phrynosoma taurus.  相似文献   

14.
Phylogenetic relationships of 34 passerines were studied based on mitochondrial Cytochrome b (Cyt b) sequences. Phylogenetic trees were constructed using Neighbor-Joining, Maximum-Parsimony and Minimum evolution methods. The results show that the divergence between Fringillids and Emberizids reaches a family level and they should be grouped into family Fringillidae and Emberizidae, respectively; Accentors has a relatively close relationship with Fringillids and Emberizids; the divergence between robins and flycatchers does not reach a family level and they should be member to family Muscicapidae; long-tailed tits and sylviids should all be listed into families; barn swallow, crowtits and long-tailed tits have close relationships with Sylviidae; in the Fringillidae, brambling should be member to one subfamily Fringillinae, several other birds under the subfamily Carduelinae; in the Sylviidae, although lanceolated warblers and scaly-headed stubtails have a relatively far relationship, they should be member to one subfamily Acrocephalinae and warblers to Phylloscopinae. Muscicapidae, Fringillidae and Emberidae are all monophylies, but Sylviidae is not. The substitution rates of major clades are thought to be the same according to relative rate tests. Divergence time of major clades is estimated at the rate of 1.6% per million years, thus the estimated divergence time between Fringillidae and Emberizidae is 10.5 million years, robins and flycatchers 9.0 Myr, Acrocephalinae and Phylloscopinae 9.0 Myr, Carduelis flammea and Carpodacus erythrinus 7.5 Myr, Luscinia cyane and Tarsiger cyanurus 7.8 Myr, two outgroups 13.5 Myr.  相似文献   

15.
The phylogenetic relationships of Peniocereus (Cactaceae) species were studied using parsimony analyses of DNA sequence data. The plastid rpl16 and trnL-F regions were sequenced for 98 taxa including 17 species of Peniocereus, representatives from all genera of tribe Pachycereeae, four genera of tribe Hylocereeae, as well as from three additional outgroup genera of tribes Calymmantheae, Notocacteae, and Trichocereeae. Phylogenetic analyses support neither the monophyly of Peniocereus as currently circumscribed, nor the monophyly of tribe Pachycereeae since species of Peniocereus subgenus Pseudoacanthocereus are embedded within tribe Hylocereeae. Furthermore, these results show that the eight species of Peniocereus subgenus Peniocereus (Peniocereus sensu stricto) form a well-supported clade within subtribe Pachycereinae; P. serpentinus is also a member of this subtribe, but is sister to Bergerocactus. Moreover, Nyctocereus should be resurrected as a monotypic genus. Species of Peniocereus subgenus Pseudoacanthocereus are positioned among species of Acanthocereus within tribe Hylocereeae, indicating that they may be better classified within that genus. A number of morphological and anatomical characters, especially related to the presence or absence of dimorphic branches, are discussed to support these relationships.  相似文献   

16.
Phylogenetic relationships among chain-forming Cochlodinium species, including the harmful red tide forming dinoflagellate Cochlodinium polykrikoides, were investigated using specimens collected from coastal waters of Canada, Hong Kong, Japan, Korea, Malaysia, México, Philippines, Puerto Rico, and USA. The phylogenetic tree inferred from partial (D1–D6 regions) large subunit ribosomal RNA gene (LSU rDNA) sequences clearly differentiated between C. polykrikoides and a recently described species, Cochlodinium fulvescens. Two samples collected from the Pacific coasts of North America (British Columbia, Canada and California, USA) having typical morphological characters of C. fulvescens such as the sulcus located in the intermediate region of the cingulum, were closely related to C. fulvescens from western Japan in the phylogenetic tree. Cochlodinium polykrikoides formed a monophyletic group positioned as a sister group of the C. fulvescens clade with three well-supported sub-clades. These three clades were composed of (1) East Asian, including specimens collected from Hong Kong, western Japan, and southern Korea, (2) Philippines, from Manila Bay, Philippines and Omura Bay, Japan, and (3) American/Malaysian, from the Atlantic coasts of USA, the Pacific coast of México, Puerto Rico, and Borneo Island, Malaysia. Each of these clades is considered to be a so-called “ribotype” representing the population inhabiting each region, which is distinguished based on ribosomal RNA gene sequences in the species despite similarities in their morphological characters.  相似文献   

17.
GlyptothoraxBlyth (1860) is the most species-diverse and widely-distributed genus in the Sisoridae, but few studies have examined monophyly of the genus and phylogenetic relations within it. We used the nuclear RAG2 gene and mitochondrial COI and Cyt b genes from 50 of the approximately 70 species to examine monophyly of Glyptothorax and phylogenetic relationships within the genus. Molecular phylogenetic trees were constructed using maximum parsimony, maximum likelihood and Bayesian inference methods. All methods strongly supported monophyly of Glyptothorax, with Bagarius as its sister group. Both analyses of two- and three-gene datasets recovered nine major subclades of Glyptothorax, but some internal nodes remained poorly resolved. The phylogenetic relationships within the genus and existing taxonomic problems are discussed.  相似文献   

18.
As with most platyrrhines, the systematics of Ateles is under discussion. In order to help clarify its systematic, we employed chromosomic and molecular characters to analyze the phylogenetic relationship among some species of the genus Ateles. Chromosomic studies were conducted on 14 atelid specimens: eight Ateles from A. paniscus, A. chamek, A. belzebuth and A. geoffroyi, and six Alouatta caraya. Ateles paniscus showed 2N=32, whereas A. chamek, A. belzebuth and A. geoffroyi presented 2N=34, XX/XY (with a submetacentric X and a variable Y) corroborated by male meiosis. Nucleotide sequence variation at the mitochondrial cytochrome c oxidase subunit II gene (COII) was analyzed in ten New World monkey specimens. Parsimony trees showed consistent phylogenetic relationships using both chromosomic forms and mitochondrial COII gene sequences as characters. Particularly, chromosomic phylogenies showed A. hybridus as a divergent taxon from the remaining group, whereas A. chamek, A. belzebuth and A. marginatus form an unresolved clade with A. geoffroyi as sister group.  相似文献   

19.
The aim of this work was to clarify taxonomy and examine evolutionary relationships within European Ceriporiopsis species using a combined analysis of the large subunit (nLSU) nuclear rRNA and small subunit (mtSSU) mitochondrial rRNA gene sequences. Data from the ITS region were applied to enhance the view of the phylogenetic relationships among different species. The studied samples grouped into four complex clades, suggesting that the genus Ceriporiopsis is polyphyletic. The generic type Ceriporiopsis gilvescens formed a separate group together with Ceriporiopsis guidella and Phlebia spp. in the phlebioid clade. In this clade, the closely related species Ceriporiopsis resinascens and Ceriporiopsis pseudogilvescens grouped together with Ceriporiopsis aneirina. C. resinascens and C. pseudogilvescens have identical LSU and SSU sequences but differ in ITS. Ceriporiopsis pannocincta also fell in the phlebioid clade, but showed closer proximity to Gloeoporus dichrous than to C. gilvescens or C. aneirinaC. pseudogilvescensC. resinascens group. Another clade was composed of a Ceriporiopsis balaenaeCeriporiopsis consobrina group and was found to be closely related to Antrodiella and Frantisekia, with the overall clade highly reminiscent of the residual polyporoid clade. The monotypic genus Pouzaroporia, erected in the past for Ceriporiopsis subrufa due to its remarkable morphological differences, also fell within the residual polyporoid clade. Ceriporiopsis subvermispora held an isolated position from the other species of the genus. Therefore, the previously proposed name Gelatoporia subvermispora has been adopted for this species. Physisporinus rivulosus appeared unrelated to two other European Physisporinus species. Moreover, Ceriporiopsis (=Skeletocutis) jelicii grouped in a separate clade, distinct from Ceriporiopsis species. Finally, the ITS data demonstrated the proximity of some Ceriporiopsis species (Ceriporiopsis portcrosensis and Ceriporiopsis subsphaerospora) to Skeletocutis amorpha.  相似文献   

20.
We reconstructed the matrilineal phylogeny of Asian algae-eating fishes of the genus Capoeta based on complete mitochondrial gene for cytochrome b sequences obtained from 20 species sampled from the majority of the range and 44 species of closely related barbs of the genera Barbus s. str. and Luciobarbus. The results of this study show that Capoeta forms a strongly supported monophyletic subclade nested within the Luciobarbus clade, suggesting that specialized scraping morphology appeared once in the evolutionary history of the genus. We detected three main groups of Capoeta: the Mesopotamian group, which includes three species from the Tigris-Euphrates system and adjacent water bodies, the Anatolian-Iranian group, which has the most diversified structure and encompasses many species distributed throughout Anatolian and Iranian inland waters, and the Aralo-Caspian group, which consists of species distributed in basins of the Caspian and Aral Seas, including many dead-end rivers in Central Asia and Northern Iran. The most probable origination pathway of the genus Capoeta is hypothesized to occur as a result of allopolyploidization. The origin of Capoeta was found around the Langhian-Serravallian boundary according to our molecular clock. The diversification within the genus occurred along Middle Miocene-Late Pliocene periods.  相似文献   

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