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1.
The anterior half of the mitochondrial 16S rRNA gene (ca. 610bp) was compared for two color morphs (spotted and lined types) of a dark-striped cardinalfish, previously identified as Apogon taeniophorus. Phylogenetic analyses using maximum-parsimony (MP) and neighbor-joining (NJ) methods, with haplotypes of A. cookii as an outgroup, showed that the haplotypes of each color-morph were reciprocally monophyletic with 100% bootstrap values. In addition, the degree of sequence difference between the two morphs was comparable to that existing between the other clearly distinct congeneric species. These results, together with the differences in coloration and overlapped geographical ranges, indicated that the two color morphs of A. taeniophorus represent two distinct species.  相似文献   

2.
Wood mice of the genus Apodemus belong to the most frequent and epidemiologically important rodents of Europe and adjacent regions. Previous studies showed that in the Middle East region species of this genus exhibit extraordinary morphological similarity precluding their proper determination without application of molecular characters. In order to determine the species of the studied populations and to obtain an insight into their phylogeographic history, we analyzed their genetic variation. We sequenced 1139 bp fragment of the mitochondrial DNA control region and flanking tRNA genes in samples collected from six localities. Phylogenetic analyses revealed presence of distinct clades corresponding to species A. uralensis and A. witherbyi. In most localities we confirmed presence of both species which suggests their large sympatric and syntopic occurrence. We recognized an extensive genetic variability, 38 specimens of A. uralensis belong to 32 distinct haplotypes, while 19 specimens of A. witherbyi to 14 haplotypes. We confirmed presence of several distinct haplotypes that may originate from multiple wood mouse colonization waves from distinct geographic regions.  相似文献   

3.
The genetic relationships among northern South China Sea populations of the six bar wrasse (Thallasoma hardwicki) were investigated. Fish collected from the Solomon Islands were used for geographic comparison. In 1998 and 1999, a total of 100 fish were sampled from 6 localities of the northern South China Sea and 3 localities of the Solomon Islands. Genetic variations in DNA sequences were examined from the first hypervariable region (HVR-1) of the mitochondrial control region, as amplified by polymerase chain reaction. High levels of haplotypic diversity (h = 0.944 ± 0.0016, = 0.0224 ± 0.01171) in the HVR-1 region of the mitochondrial control region of T. hardwicki were detected. This yielded 94 haplotypes that exhibited a minimum spanning tree with a starburst structure, suggestive of a very recent origin for most haplotypes. Neutrality tests indicated that the pattern of genetic variability in T. hardwicki is consistent either with genetic hitchhiking by an advantageous mutation or with population expansion. Partitioning populations into coherent geographic groups divided the northern South China Sea samples (CT = 0.0313, P < 0.001) into 3 major groups: a north-central group composed of northwestern Taiwan and northern Vietnam; a southwestern group containing southern Vietnam; and a southern group including the central Philippines. These results are in concordance with mesoscale boundaries proposed by allozyme markers, thus highlighting the importance of identifying transboundary units for the conservation and management of fisheries in the South China Sea.  相似文献   

4.
Mitochondrial DNA divergence among populations of the Japanese spinous loach Cobitis shikokuensis, endemic to Shikoku Island, was investigated by restricted fragment length polymorphism analysis. A total of 68 restriction sites on DNA fragments from the cytochrome b to D-loop regions and from the 12S rRNA to 16S rRNA regions, amplified by PCR, were analyzed. A total of 12 haplotypes (plus 6 in outgroups) were detected in 268 specimens collected from 19 localities in seven rivers (and 41 specimens from four localities in three rivers in outgroups). Three of the seven river populations of C. shikokuensis were shown to have unique haplotypes, and four of the seven river populations were monomorphic. The nested structure of the haplotype network for populations of C. shikokuensis exhibited two large clades corresponding to (1) populations from the Shimanto River and its neighbors and (2) two genetically divergent populations in the Shigenobu and Iwamatsu Rivers. The population from the Shimanto River, the largest river inhabited by C. shikokuensis, maintains great haplotype diversity as well as the allozyme diversity previously reported. On the other hand, populations from the Hiji River, the second largest river, which exhibited the highest allozyme diversity, were monomorphic in their mtDNA. The nested clade analysis (NCA) revealed that past fragmentation between the above two clades could occur in the initial distribution process of C. shikokuensis. The large genetic divergence of two river populations from the Shigenobu and Iwamatsu Rivers was inferred to be caused by a process of long distance colonization and fragmentation. MtDNA introgression into the Hiji River population from southern river populations was suggested. Taking genetic divergence into consideration, each river population of C. shikokuensis should be conserved separately as like a distinct species, and conservation programs for the small populations showing less genetic variability should be invoked as soon as possible.  相似文献   

5.
The objectives of this study were to identify single nucleotide polymorphisms (SNPs) and resulting haplotypes in the bovine CXCR2 gene. A 311-bp segment of the bovine CXCR2 gene was amplified and sequenced. Five SNPs at positions 612, 684, 777, 858, and 861 were expressed in both Holstein and Jersey dairy cattle. Four SNPs resulted in synonymous substitutions, while a non-synonymous switch at position 777 (GC) resulted in a glutamine to histidine substitution at amino acid residue 245. Strong linkage disequilibrium was exhibited for both breeds among all five loci (P<0.001). Both allele and genotype frequencies differed significantly with respect to breed at four of the five loci (P<0.001). The five polymorphisms generated ten distinct haplotypes. Six haplotypes were common between the two breeds, while Holsteins and Jerseys each uniquely expressed two haplotypes. Of the six common haplotypes, two represented 83% of the Jersey population; whereas four of these haplotypes represented 95% of the Holstein population.  相似文献   

6.
A new type of exterilium larvae referable to Leptobrotula (Ophidiiformes: Ophidiidae) is described on the basis of two specimens (20.7+mm and ca. 35.4mmSL) collected from the tropical Indo-Pacific. They are characterized, in particular, by several elongated anterior dorsal fin rays supported by the large dorsal pterygiophores and the exterilium gut bearing filamentous appendages along the ventral border. It is suggested from larval evidence that Leptobrotula forms a distinct lineage with Brotulotaenia and Lamprogrammus, which may be placed in an expanded Brotulonaeniinae.  相似文献   

7.
A new cottid species, Microcottus matuaensis, is described on the basis of 16 specimens (27.9–81.3mm SL) collected from tide pools of Matua Island, central Kuril Archipelago. This species is the second species of the genus Microcottus, and is distinguished from M. sellaris in having three pairs of distinct bony tubercles on the dorsal surface of occiput, a deeply concave interorbital space, and absence of the first pore of the supraorbital sensory canal.  相似文献   

8.
A new rockfish, Sebastes kiyomatsui, is described on the basis of 13 specimens from the Pacific coast of southern Japan. The new species resembles S. scythropus in having two sharp preorbital and robust preocular, supraocular, and postocular spines, but differs from the latter in having a black blotch on the opercle not extending to the subopercle, indistinct crimson marks on the body, blackish region of the oral cavity reaching to the prevomer and palatine, blackish tongue, a small ridge on the upper edge of the lachrymal, somewhat larger orbit, somewhat lower caudal peduncle, and seven lower unbranched pectoral fin rays. Sebastes kiyomatsui is a deep water (ca. 250m) inhabitant.  相似文献   

9.
Narita S  Nomura M  Kato Y  Yata O  Kageyama D 《Genetica》2007,131(3):241-253
The common yellow butterfly Eurema hecabe is widely distributed in East Asia, and is one of the most burdensome species for taxonomists due to the numerous geographic and seasonal wing colour patterns. Moreover, within this species, individuals with a yellow wing fringe that occur in temperate regions of Japan (Y type) proved to be biologically different from others that occur widely in subtropical regions of Japan and all over East Asia (B type). To unveil the genetic variation within and between the two types, a total of 50 butterflies collected at 18 geographic localities in East Asia were examined for nucleotide sequence variation of three mitochondrial regions: cytochrome c oxidase subunit I (COI), cytochrome c oxidase subunit III (COIII) and NADH dehydrogenase subunit 5 (ND5). In addition, they were also examined for infection status with the endosymbiotic bacteria Wolbachia. The three mitochondrial sequences consistently showed that (i) Y type and B type were highly divergent, (ii) nucleotide variation within B type was very small although sampled from a geographically wide range, and (iii) a weak association existed between mitochondrial DNA haplotypes and Wolbachia infection status.  相似文献   

10.
Gomphiocephalus hodgsoni (Collembola) is the most common and widely distributed arthropod in the Dry Valleys of southern Victoria Land, and is genetically diverse with over 70 mitochondrial cytochrome c oxidase subunit I (COI) haplotypes. There is also considerable physiological variation among G. hodgsoni individuals in their cold tolerance and metabolic activity. Here, we assessed genetic haplotypes of G. hodgsoni relative to the environmental conditions during which individuals were active. We sequenced the COI region of 151 individuals collected in pitfall traps from three sites within Taylor Valley and found 19 unique haplotypes that separated into two distinct lineages (1.6 % divergence), with one lineage comprising 80 % of the sequenced population. During two-hourly sampling, air temperature was the strongest predictor of activity between the two lineages (R 2 = 0.56), and when combined with subsurface soil temperature, relative humidity and photosynthetically active radiation, explanatory power increased to R 2 = 0.71. With steadily increasing air temperatures predicted for much of Antarctica, it is likely that some haplotypes will have a selective advantage and potentially result in decreased genetic variability within populations. We suggest that temporal monitoring of the relative proportions of COI haplotypes or other appropriate genetic markers may provide a subtle measure of biological responses to environmental changes within Antarctic terrestrial ecosystems.  相似文献   

11.
To test the association between Pleistocene forest dynamics relative to elevation and the population dynamics of arboreal small mammals, we examined the phylogeographical predictions for the genetic structure of the red and white giant flying squirrel (Petaurista alborufus lena) and the Indian giant flying squirrel (P. philippensis grandis) using complete mitochondrial control region sequences. Both giant flying squirrels are endemic subspecies to Taiwan and are sympatric in much of their range. In the phylogenetic analyses, we included 35 specimens of P. alborufus lena collected from 20 localities and five specimens with unknown sampling localities. Also, we phylogenetically examined 32 specimens of P. philippensis grandis from 18 localities and three specimens with unknown sampling localities. We identified 36 haplotypes of P. alborufus lena and 33 haplotypes of P. philippensis grandis. Although we did not recognize major phylogroups, we found several minor phylogroups in both subspecies, suggesting similar evolutionary histories. Phylogeographical and demographic tests showed distributions of these two subspecies expanded into coniferous and mixed forests that developed during glaciation in Taiwan's lowlands and middle lands. This suggests that these two Petaurista subspecies shifted elevation from mountainous areas to lowlands during glaciation. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 404–419.  相似文献   

12.
Samples of Mytilus were collected at eight sites located in and around Bergen, Norway, and analysed by starch gel electrophoresis for the two highly polymorphic loci PGM* and PGI*. The genotype distribution and allele frequencies varied significantly among samples from the different locations. The variations were most significant between localities with full strength seawater and brackish water, and this difference was so large that it indicated the presence of two populations, possibly representing two species. The brackish water mussels may represent the species Mytilus trossulus, while the species Mytilus edulis may be distributed on the outer shores where salinity is normally around 30. Differential survival, as a result of specific adaptation to different salinities, may be the mechanism that maintains the populations (or species) and prevents gene flow between them.Communicated by H.-D. Franke  相似文献   

13.
The first standard nomenclature for the chicken (Gallus gallus) major histocompatibility (B) complex published in 1982 describing chicken major histocompatibility complex (MHC) variability is being revised to include subsequent findings. Considerable progress has been made in identifying the genes that define this polymorphic region. Allelic sequences for MHC genes are accumulating at an increasing rate without a standard system of nomenclature in place. The recommendations presented here were derived in workshops held during International Society of Animal Genetics and Avian Immunology Research Group meetings. A nomenclature for B and Y (Rfp-Y) loci and alleles has been developed that can be applied to existing and newly defined haplotypes including recombinants. A list of the current standard B haplotypes is provided with reference stock, allele designations, and GenBank numbers for corresponding MHC class I and class II sequences. An updated list of proposed names for B recombinant haplotypes is included, as well as a list of over 17 Y haplotypes designated to date.  相似文献   

14.
In the loach Misgurnus anguillicaudatue, the asexual lineage, which produces unreduced clonal diploid eggs, has been identified. Among 833 specimens collected from 54 localities in Japan and two localities in China, 82 candidates of other lineage(s) of cryptic clones were screened by examining RFLP (restriction fragment length polymorphism)-PCR haplotypes in the control region of mtDNA. This analysis was performed because triploid loaches arise from the accidental incorporation of the sperm nucleus into unreduced diploid eggs of a clone. The categorization of members belonging to three newly identified lineages (clones 2–4) and the previously identified clonal lineage (clone 1) was verified by evaluating the genetic identity between two or more individuals from each clonal lineage based on RAPD (random amplified polymorphic DNA)-PCR and multilocus DNA fingerprints. We detected 75 haplotypes by observing the nucleotide status at variable sites from the control region of mtDNA. Phylogenic trees constructed from such sequences showed two highly diversified clades, A and B, that were beyond the level common for interspecific genetic differentiation. That result suggests that M. anguillicaudatus in Japan is not a single species entity. Two clone-specific mtDNA sequences were included in clade A, and the loaches with such sequences may be the maternal origin of the clones. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

15.
Anguillid eels have been believed to have a unique catadromous life history completed within a particular ocean current system, and consequently to have extraordinary population structures, with each species comprising a single, virtually panmictic population with a species-specific spawning area far offshore. The giant mottled eel Anguilla marmorata is enigmatic in this respect because it is widely distributed from East Africa to the central South Pacific, where several different current systems exist, and apparently must have multiple spawning areas. To address this issue, the population structure was examined through the mitochondrial (mt) DNA analysis of 162 individuals collected from ten localities representing the overall distributional range. Nucleotide sequencing of a 626-bp segment in the control region of the mtDNA revealed 151 haplotypes, and these were clustered into several major groups supported by high bootstrap probabilities. Sequence differences among geographic samples revealed the existence of five geographic populations around North Pacific, Madagascar, Sumatra, Fiji, and Tahiti. Genetic differentiation among the populations in the Southern Hemisphere was supported by examination of nuclear DNA with amplified fragment length polymorphism (AFLP) analysis performed on 76 individuals from four sampling localities in the Southern Hemisphere. The distribution pattern of five populations was closely associated with the water-mass structure of oceans and major current systems. This observation suggests a hypothesis that present population differentiation in A. marmorata might have resulted from the establishment of new population-specific spawning sites in different oceanic current systems as the species colonized new areas, as its unique catadromous life history of anguillid eels.This revised version was published online in February 2005 with corrections to the repetition of the 1st authors name.  相似文献   

16.
Summary Acremonium spp. endophytes are mutualistic fungal symbionts of many C3 grasses. They are anamorphs of Epichloë typhina (Clavicipitaceae) that have become strictly seedborne, heritable components of symbiotic units (symbiota). In order to test the possibility that endophytes may contribute to the genetic diversity of symbiota, a survey was conducted of plants from nine populations of Festuca arizonica in the southern Rocky Mountains. Sequence analysis of rRNA gene segments distinguished three Acremonium endophyte types. Parsimony analysis indicated at least two distinct evolutionary origins of the Acremonium endophytes from E. typhina. Either or both of these evolutionary lineages may have involved cospeciation with the host.  相似文献   

17.
Summary The advent of direct sequencing via the polymerase chain reaction (PCR) has opened up the possibility of molecular studies on museum specimens. Here we analyze genetic variation in populations over time by applying PCR to DNA extracted from museum specimens sampled from populations of one species over the last 78 years. Included in this study were 43 museum specimens of the Panamint kangaroo ratDipodomys panamintinus from localities representing each of three geographically distinct subspecies. These specimens were originally collected and prepared as dried skins in 1911, 1917, or 1937. For each specimen, a 225-bp segment of the mitochondrial genome was sequenced. These mitochondrial DNA sequences were compared to those of 63 specimens collected at the same localities in 1988. The three subspecies were nearly completely distinct. Only 2 of the 106 individuals shared mitochondrial types between subspecies. For all three localities, the diversity levels were maintained between the two temporal samples. The concordance observed between the two temporally separate phylogenies supports the use of museum specimens for phylogenetic inference. This study demonstrates the accuracy and routine nature of the use of museum specimens in the analysis of mitochondrial sequence variation in natural populations and, importantly, that a temporal aspect can now be added to such studies.  相似文献   

18.
Capoeta mandica was originally described as C. barroisi mandica from Mond River, Persian Gulf basin, based on morphological characters and later was considered as a distinct species based on a few small specimens. However, there is still controversial debate about its systematic position and morphological characters. To resolve the issue, new collected specimens from Iranian drainage basins examined morphologically and molecularly. Results revealed that C. mandica is a distinct taxon in the Capoeta trutta group. This taxon confirms the zoogeographical separation of the Persis basin (southern Iran) by the rise in post-Pleistocene sea level, isolating rivers from the Tigris-Euphrates and western basins.  相似文献   

19.
Sequences of the esterase gene E7 were compared across 41 isogenic (IV) strains of the sheep blowfly, Lucilia cuprina, and one strain of the sibling species, L. sericata. The 1.2-kb region sequenced includes sites of two insecticide resistance mutations. Gly137Asp confers resistance to organophosphorus insecticides (OPs), particularly preferring diethyl OPs such as diazinon, while Trp251Leu prefers dimethyl OPs, and particularly malathion, with the additional presence of carboxylester moieties. We found that there are just eight haplotypes among the 41 chromosomes studied: two Gly137Asp containing haplotypes, two Trp251Leu containing haplotypes, and four susceptible haplotypes, including the L. sericata sequence. While phylogenetic analysis of these haplotypes suggests that the Asp137 and Leu251 mutations each arose at least twice, evidence for recombination was detected across the region, therefore single origins for these resistance mutations cannot be ruled out. Levels of linkage disequilibrium in the data are high and significant hitchhiking is indicated by Fay and Wu s H test but not the Tajima test. A test of haplotype diversity indicates a paucity of diversity compared with neutral expectations. Both these results are consistent with a very recent selective sweep at the LcE7 locus. Interestingly, gene duplications of three different combinations of OP resistant haplotypes were identified in seven of the isogenic (IV) strains. All three types of duplication involve an Asp137 and a Trp251 haplotype. To examine whether more haplotypes existed before the hypothesised selective sweep, fragments of E7 surrounding the resistance mutations were amplified from pinned material dating back to before OPs were used. Four new sequence haplotypes, not sampled in the survey of extant haplotypes, were obtained that are all associated with susceptibility. This is suggestive of a higher historical level of susceptible allelic diversity at this locus.Reviewing Editor: Dr. Rasmus Nielsen  相似文献   

20.
We examined sequence variation in the mitochondrial cytochrome b and NADH dehydrogenase subunit 5 genes (2,360 bp total) for 26 lions from eleven locations throughout sub-Saharan Africa. Six distinct haplotypes were observed in the combined sequences, forming two clades: the eastern and the western savannas. The Uganda-Western Kenya haplotype grouped at a basal position with the eastern clade of lions from Tsavo south to the Transvaal and Natal regions. The phylogenetic position of the haplotype from Sabi Sands in the southern part of Kruger National Park remained poorly resolved. The haplotypes found in Namibia and Botswana formed the western clade. The modest genetic variation documented here argues against taxonomic distinctions among living African lions.  相似文献   

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