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Origin and phylogeographical structure of Chinese cattle   总被引:7,自引:0,他引:7  
Lei CZ  Chen H  Zhang HC  Cai X  Liu RY  Luo LY  Wang CF  Zhang W  Ge QL  Zhang RF  Lan XY  Sun WB 《Animal genetics》2006,37(6):579-582
Complete mitochondrial D-loop sequences of 231 samples were used to explore the origin and genetic diversity of Chinese cattle. Phylogenetical analysis of these sequences revealed both Bos taurus and Bos indicus mitochondrial types in Chinese cattle. Four of the previously identified mitochondrial DNA lineages (T1–T4) were identified in the Bos taurus type, including lineage T1, which was found for the first time in Chinese cattle. Two lineages (I1 and I2) were identified in the Bos indicus type. Our results support the suggestion that the Yunnan-Guizhou Plateau is the domestication site of Chinese zebu. We also found evidence that Tibetan cattle originated from taurine and zebu cattle. The distribution pattern of Chinese cattle breeds was closely related to the geographical and climatic background. It was possible to divide Chinese cattle in this study into two major groups: northern and southern cattle.  相似文献
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Genetic divergences and population structures were examined in the cryptic Lethenteron sp. N and sp. S, based on mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (CO I) region sequences. An improved method of discrimination between L . sp. N and sp. S was found using PCR, with diagnostic primers for each species-specific sequence in the mtDNA CO I region. Identification of 50 individuals of each species by this analysis was consistent with that by allozyme analysis of nuclear DNA. L . sp. N and sp. S, identified on the basis of diagnostic alleles at five allozymic loci, were independently grouped in a neighbour-joining (NJ) tree, with a large sequence difference (mean ±  s . d . = 9·10 ± 0·36%) between them. Within each species, the values of sequence divergence among localities were significantly higher in L . sp. S (1·61 ± 0·44%) than in L . sp. N (1·10 ± 0·48%). On the tree and nested clade analyses, several phylogenetic groups comprising geographically close localities were detected in the former, although scarcely detected in the latter, probably resulting from dispersal pattern differences between them.  相似文献
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Mitochondrial DNA (mtDNA) sequences were used to evaluate phylogeographic structure within and among populations of three endangered Hawaiian tree snail species (n = 86). The primary focus of this investigation was on setting conservation priorities for Achatinella mustelina. Limited data sets for two additional endangered Hawaiian tree snails, A. livida and A. sowerbyana, were also developed for comparative purposes. Pairwise genetic distance matrices and phylogenetic trees were generated, and an analysis of molecular variance was performed on 675-base pair cytochrome oxidase I gene sequences from multiple populations of Hawaiian tree snails. Sequence data were analysed under distance-based maximum-likelihood, and maximum-parsimony optimality criteria. Within the focal species, A. mustelina, numbers of variable and parsimony informative sites were 90 and 69, respectively. Pairwise intraspecific mtDNA sequence divergence ranged from 0 to 5.3% in A. mustelina, from 0 to 1.0% in A. livida and from 0 to 1.9% in A. sowerbyana. For A. mustelina, population genetic structure and mountain topography were strongly correlated. Maximum genetic distances were observed across deep, largely deforested valleys, and steep mountain peaks, independent of geographical distance. However, in certain areas where forest cover is presently fragmented, little mtDNA sequence divergence exists despite large geographical scales (8 km). Genetic data were used to define evolutionarily significant units for conservation purposes including decisions regarding placement of predator exclusion fences, captive propagation, re-introduction and translocation.  相似文献
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It has been hypothesized that species living in small lentic water bodies, because of the short-term geological persistence of their habitat, should show higher dispersal ability, with increased gene flow among populations and a less pronounced phylogeographical structure. Conversely, lotic species, living in more geologically stable habitats, should show reduced dispersal and an increased phylogeographical structure at the same geographical scales. In this work we tested the influence of habitat type in two groups of aquatic Coleoptera ( Nebrioporus ceresyi and Ochthebius notabilis groups, families Dytiscidae and Hydraenidae respectively), each of them with closely related species typical of lotic and lentic saline Western Mediterranean water bodies. We used mitochondrial cox1 sequence data of 453 specimens of 77 populations through the range of nine species to compare a lotic vs. a lentic lineage in each of the two groups. Despite the differences in biology (predators vs. detritivorous) and evolutionary history, in both lotic lineages there was a higher proportion of nucleotide diversity among than within groups of populations, and a faster rate of accumulation of haplotype diversity (as measured by rarefaction curves) than in the lentic lineages. Similarly, lotic lineages had a higher absolute phylogenetic diversity, more remarkable considering their smaller absolute geographical ranges. By comparing closely related species, we were able to show the effect of contrasting habitat preferences in two different groups, in agreement with predictions derived from habitat stability.  相似文献
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The beet armyworm, Spodoptera exigua (Lepidiptera: Noctuidae), is an important agricultural pest in China, causing serious economic losses in the main welsh onion‐producing areas of North China. In order to effectively monitor and manage this pest, it is necessary to investigate its genetic variation and intraspecific phylogeographic structure in North China. In this study, we used a DNA fragment of cytochrome oxidase subunit I (COI) consisting of 518 bps to investigate its genetic diversity. A total of 500 individuals of this species were collected from 20 geographic locations, and 8 haplotypes were identified. Low levels of genetic diversity (= 0.256 ± 0.025, π = 0.00058 ± 0.00008) for the total populations in these study regions were obtained. Phylogenetic and median‐joining network analyses indicated that there was no distinct geographic distribution pattern among haplotypes. The results also indicated that the mean pairwise sequence difference between the populations was 0.1%, ranged from zero to 0.2%. The genetic differentiation (Fst) between the populations varied from −0.198 to 0.656, and there was a significant differentiation between the population of Kunshan (KUNS), Shenyang (SY), Lucheng (LUC), Binzhou (BZ) and the remaining populations, respectively. The analysis of molecular variance (amova ) showed that the percentage of variation within a population (69.05%) was greater than that between the populations (30.95%), and the level of population differentiation (FST = 0.310, P < 0.001) was highly significant after 1000 random permutations. Finally, unimodal mismatch distribution combined with negative, Tajima's D (= −1.956, P < 0.05) and Fu's Fs (Fs = −5.875, P > 0.05) indicated that S. exigua experienced recent population expansion in North China.  相似文献
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