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1.
This study aims to improve the estimates of fine-scale genetic diversity and to compare the population structure of Siniperca scherzeri with nuclear and mitochondrial DNA (mtDNA) markers. We first combined mtDNA sequences and seven microsatellite loci to examine the genetic diversity of S. scherzeri in China. Phylogenetic and nested clade analyses revealed two major mtDNA lineages and four subclades. Bayesian multilocus genotype clustering from the microsatellite loci revealed that regional divergence estimates were quantitatively congruent between marker classes. These lineages should be recognized as the basic evolutionary significant units for S. scherzeri in China. Contradict to the previous studies on Coreoperca whiteheadi and Siniperca chuatsi, neither the Nanling–Wuyi Mountain range nor the Qingling–Dabie Mountain range represented a major phylogeographic barrier for S. scherzeri. Our fine-scale analyses of the genetic population structure of S. scherzeri provided insights into the evolutionary processes that shaped the genetic heterogeneity of this fish. This study may serve as a basis for the protection, monitoring and breeding improvement of germplasm resources of this commercially important fish.  相似文献   

2.

Background

Metabolism of energy nutrients by the mitochondrial electron transport chain (ETC) is implicated in the aging process. Polymorphisms in core ETC proteins may have an effect on longevity. Here we investigate the cytochrome b (cytb) polymorphism at amino acid 7 (cytbI7T) that distinguishes human mitochondrial haplogroup H from haplogroup U.

Principal Findings

We compared longevity of individuals in these two haplogroups during historical extremes of caloric intake. Haplogroup H exhibits significantly increased longevity during historical caloric restriction compared to haplogroup U (p = 0.02) while during caloric abundance they are not different. The historical effects of natural selection on the cytb protein were estimated with the software TreeSAAP using a phylogenetic reconstruction for 107 mammal taxa from all major mammalian lineages using 13 complete protein-coding mitochondrial gene sequences. With this framework, we compared the biochemical shifts produced by cytbI7T with historical evolutionary pressure on and near this polymorphic site throughout mammalian evolution to characterize the role cytbI7T had on the ETC during times of restricted caloric intake.

Significance

Our results suggest the relationship between caloric restriction and increased longevity in human mitochondrial haplogroup H is determined by cytbI7T which likely enhances the ability of water to replenish the Qi binding site and decreases the time ubisemiquinone is at the Qo site, resulting in a decrease in the average production rate of radical oxygen species (ROS).  相似文献   

3.
An analysis of the dietary content of haematophagous insects can provide important information about the transmission networks of certain zoonoses. The present study evaluated the potential of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome B (cytb) gene to differentiate between vertebrate species that were identified as possible sources of sandfly meals. The complete cytb gene sequences of 11 vertebrate species available in the National Center for Biotechnology Information database were digested with Aci I, Alu I, Hae III and Rsa I restriction enzymes in silico using Restriction Mapper software. The cytb gene fragment (358 bp) was amplified from tissue samples of vertebrate species and the dietary contents of sandflies and digested with restriction enzymes. Vertebrate species presented a restriction fragment profile that differed from that of other species, with the exception of Canis familiaris and Cerdocyon thous. The 358 bp fragment was identified in 76 sandflies. Of these, 10 were evaluated using the restriction enzymes and the food sources were predicted for four: Homo sapiens (1), Bos taurus (1) and Equus caballus (2). Thus, the PCR-RFLP technique could be a potential method for identifying the food sources of arthropods. However, some points must be clarified regarding the applicability of the method, such as the extent of DNA degradation through intestinal digestion, the potential for multiple sources of blood meals and the need for greater knowledge regarding intraspecific variations in mtDNA.  相似文献   

4.
Translocation records indicate aoudad (Ammotragus lervia) populations in the United States are a product of multiple human‐mediated introductions. Two mitochondrial markers (cytochrome b, cytb; displacement loop, D loop) and one nuclear gene (prion protein gene exon 3, PRNP) were used to determine: (1) genetic variation, (2) if genetic units correspond to taxonomic designations, (3) the number and geographic origin of translocations, and (4) divergence times. Three phylogenetic analyses (Bayesian inference, maximum likelihood, and parsimony) produced similar topologies with two clades (I and II). Clade I contained progeny of individuals resulting from introductions to Texas and Spain, and individuals from Algeria. Individuals in Clade II were progeny of past introductions to the United States and Europe, and northern Algeria. Clade II was subdivided into two subclades (A and B) representing two haplogroups. No genetic variation was detected in the PRNP sequences. Three haplogroups appeared to correspond to the subspecies A. l. lervia and A. l. sahariensis whose native distribution includes northwestern Africa. Network analyses assigned haplogroups to two major groups similar to those depicted in the phylogenetic analyses. Genetic distances ranged from 0.80% to 5.17% and 2.99% to 15.42% for cytb and D loop, respectively; and were higher than normally recovered for caprids, warranting a reexamination of subspecific status. Divergence dates indicated a major split between A. l. lervia and A. l. sahariensis circa 2.38 mya. Together, the high level of genetic divergences among US populations and apparent presence of two subspecies of aoudad in the United States support the hypothesis of multiple introductions from multiple sources.  相似文献   

5.
Nitrogen-fixing microbial populations in a Douglas fir forest on the western slope of the Oregon Cascade Mountain Range were analyzed. The complexity of the nifH gene pool (nifH is the marker gene which encodes nitrogenase reductase) was assessed by performing nested PCR with bulk DNA extracted from plant litter and soil. The restriction fragment length polymorphisms (RFLPs) of PCR products obtained from litter were reproducibly different than the RFLPs of PCR products obtained from the underlying soil. The characteristic differences were found during the entire sampling period between May and September. RFLP analyses of cloned nifH PCR products also revealed characteristic patterns for each sample type. Among 42 nifH clones obtained from a forest litter library nine different RFLP patterns were found, and among 64 nifH clones obtained from forest soil libraries 13 different patterns were found. Only two of the patterns were found in both the litter and the soil, indicating that there were major differences between the nitrogen-fixing microbial populations. A sequence analysis of clones representing the 20 distinct patterns revealed that 19 of the patterns had a proteobacterial origin. All of the nifH sequences obtained from the Douglas fir forest litter localized in a distinct phylogenetic cluster characterized by the nifH sequences of members of the genera Rhizobium, Sinorhizobium, and Azospirillum. The nifH sequences obtained from soil were found in two additional clusters, one characterized by sequences of members of the genera Bradyrhizobium, Azorhizobium, Herbaspirillum, and Thiobacillus and the other, represented by a single nifH clone, located between the gram-positive bacteria and the cyanobacteria. Our results revealed the distinctness of the nitrogen-fixing microbial populations in litter and soil in a Douglas fir forest; the differences may be related to special requirements for degradation and mineralization processes in the plant litter.  相似文献   

6.
The genus Meristogenys (Anura: Ranidae), endemic to Borneo, presents serious taxonomic problems despite being one of the commonest frogs in the mountainous regions of this island. We investigated molecular and morphological variations in Meristogenys whiteheadi (Boulenger, 1887) using larval and adult specimens from Sabah and Sarawak (Malaysia). We found three allopatric lineages in this species. We regard each of these as a distinct species because they are separated by a large genetic distance, and do not form any monophyletic group. Their morphological characters indicate that the distributional range of M. whiteheadi s.s. is divided into two disjunct areas: Mt Kinabalu (northern Sabah) and northern Sarawak. The two other lineages occupy ranges between those of M. whiteheadi, and represent undescribed cryptic species. One of these, Meristogenys stigmachilus sp. nov. , collected from the northern part of the Crocker Range, is distinguished from M. whiteheadi by black spots on the upper lip and dark dots scattered on the back. A second undescribed species, Meristogenys stenocephalus sp. nov. , was collected mainly from the southern part of the Crocker Range, and is characterized by the large body size of males and a relatively narrow head. Meristogenys stenocephalus sp. nov. also differs from M. stigmachilus sp. nov. and M. whiteheadi in larval morphology, but larvae of the latter two cannot be differentiated morphologically. We discuss relative tibia length, a diagnostic specific characteristic in the genus Meristogenys, and the relationships between body size and sexual size dimorphism in this genus. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 157–183.  相似文献   

7.
Handa H 《Nucleic acids research》2003,31(20):5907-5916
The entire mitochondrial genome of rapeseed (Brassica napus L.) was sequenced and compared with that of Arabidopsis thaliana. The 221 853 bp genome contains 34 protein-coding genes, three rRNA genes and 17 tRNA genes. This gene content is almost identical to that of Arabidopsis. However the rps14 gene, which is a pseudo-gene in Arabidopsis, is intact in rapeseed. On the other hand, five tRNA genes are missing in rapeseed compared to Arabidopsis, although the set of mitochondrially encoded tRNA species is identical in the two Cruciferae. RNA editing events were systematically investigated on the basis of the sequence of the rapeseed mitochondrial genome. A total of 427 C to U conversions were identified in ORFs, which is nearly identical to the number in Arabidopsis (441 sites). The gene sequences and intron structures are mostly conserved (more than 99% similarity for protein-coding regions); however, only 358 editing sites (83% of total editings) are shared by rapeseed and Arabidopsis. Non-coding regions are mostly divergent between the two plants. One-third (about 78.7 kb) and two-thirds (about 223.8 kb) of the rapeseed and Arabidopsis mitochondrial genomes, respectively, cannot be aligned with each other and most of these regions do not show any homology to sequences registered in the DNA databases. The results of the comparative analysis between the rapeseed and Arabidopsis mitochondrial genomes suggest that higher plant mitochondria are extremely conservative with respect to coding sequences and somewhat conservative with respect to RNA editing, but that non-coding parts of plant mitochondrial DNA are extraordinarily dynamic with respect to structural changes, sequence acquisition and/or sequence loss.  相似文献   

8.
Eligmodontia is a genus of phyllotine rodents adapted to arid environments with seven recognized species. The sister species E. puerulus and E. moreni are distributed in the adjacent highland Puna and lowland Monte deserts respectively, and show remarkable morphological and chromosomal differences. However, analyses of the cytochrome b gene showed important variability, without reciprocal monophyly between them. In order to study the evolutionary processes involved in the diversification of both taxa, we analyzed 1161 bp of the mitochondrial control region and flanking sequences (N = 60), as well as 759 bp of the first exon of the nuclear gene IRBP (N = 14). Individuals of both species from Jujuy, Catamarca and Mendoza Provinces of Argentina were previously karyotyped. Results showed that the mitochondrial sequences present high haplotype and nucleotide diversity within all population, and no haplotype was shared between both species. FST indicated that populations of both species were moderately structured. The network was constituted by two major haplogroups, one composed by E. puerulus samples from Jujuy, and the other composed of sequences of all studied populations. The Bayesian analysis showed three clusters, matching the network. Phylogenetic analysis recovered two clades with high support, in coincidence with the network groups. There was only one close join between sequences of both species, corresponding to samples from Catamarca. Thus, mitochondrial data suggested hybridization between both species in Catamarca, with asymmetric introgression. The IRBP showed low variability and, in the phylogenetic analysis, the sequences of E. puerulus form a monophyletic group with intermediate support, whereas those of E. moreni collapse into a basal polytomy. Our data indicated a recent divergence and absence of introgression in the nuclear genomes. The results at the population level with mitochondrial sequences, together with integrative taxonomy at the species level in a biogeographic context, suggest that climatic and geologic changes could have had an important role in the determination of genetic variability patterns observed in these rodents.  相似文献   

9.
The genetic structure of seven mainland and island Asian populations of Bombus ignitus was investigated using nine microsatellite markers and the sequences of part of the mitochondrial cytochrome b (cytb) gene. While microsatellite markers showed high genetic variability, no sequence variation was found in the cytb gene fragment analyzed. The number of microsatellite alleles ranged from 9 to 24. Gene diversities per locus per population ranged from 0.378 to 0.992. Analysis of molecular variance (AMOVA) and most pairwise F(ST) values showed significant genetic differentiation between mainland and island populations. Cytb sequences data and microsatellite bottleneck tests indicated that almost all populations were subjected to recent bottlenecks. Our results suggest that B. ignitus populations diverged due to recent bottlenecks and geographic isolation.  相似文献   

10.
A novel cytoplasmic male sterility (CMS) conferred by Dongbu cytoplasmic and genic male-sterility (DCGMS) cytoplasm and its restorer-of-fertility gene (Rfd1) was previously reported in radish (Raphanus sativus L.). Its inheritance of fertility restoration and profiles of mitochondrial DNA (mtDNA)-based molecular markers were reported to be different from those of Ogura CMS, the first reported CMS in radish. The complete mitochondrial genome sequence (239,186 bp; GenBank accession No. KC193578) of DCGMS mitotype is reported in this study. Thirty-four protein-coding genes and three ribosomal RNA genes were identified. Comparative analysis of a mitochondrial genome sequence of DCGMS and previously reported complete sequences of normal and Ogura CMS mitotypes revealed various recombined structures of seventeen syntenic sequence blocks. Short-repeat sequences were identified in almost all junctions between syntenic sequence blocks. Phylogenetic analysis of three radish mitotypes showed that DCGMS was more closely related to the normal mitotype than to the Ogura mitotype. A single 1,551-bp unique region was identified in DCGMS mtDNA sequences and a novel chimeric gene, designated orf463, consisting of 128-bp partial sequences of cox1 gene and 1,261-bp unidentified sequences were found in the unique region. No other genes with a chimeric structure, a major feature of most characterized CMS-associated genes in other plant species, were found in rearranged junctions of syntenic sequence blocks. Like other known CMS-associated mitochondrial genes, the predicted gene product of orf463 contained 12 transmembrane domains. Thus, this gene product might be integrated into the mitochondrial membrane. In total, the results indicate that orf463 is likely to be a casual factor for CMS induction in radish containing the DCGMS cytoplasm.  相似文献   

11.
We used sequences of mitochondrial cytb and 16SrRNA gene segments in order to clarify the genetic diversity and population structure in three Chinese estuary populations of Coilia mystus: 21 individuals from ChangJiang River (Yangtze River) estuary, 22 from MinJiang River estuary, and 22 from ZhuJiang River (Pearl River) estuary (65 individuals total). We obtained 607 base pairs of consensus cytb sequence. Thirty four distinct haplotypes were detected among the 65 cytb sequences. The indexes of nucleotide diversity (π) in these three populations were ChangJiang 0.533%, MinJiang 1.135%, and ZhuJiang 0.268%. MinJiang is the largest of the three populations. Genetic distances within the populations were between 0.3 and 1.2%, and 0.8 to 10.8% among populations. The largest genetic distance was 10.8% between the ChangJiang and ZhuJiang populations, and the smallest was 0.8% between MinJiang and ZhuJiang populations. Analysis of molecular variance (AMOVA) analysis revealed that variation among populations accounts for 90.25% of total variation, suggesting that this is the main source of total variance. We obtained 470 base pairs of consensus sequence of 16SrRNA. We detected 19 distinct haplotypes among the 65 sequences. The indexes of nucleotide diversity (π) in these three populations were ChangJiang 0.108%, MinJiang 0.843%, and ZhuJiang 0.097%. MinJiang is also the largest among these three populations. Genetic distances were between 0.1 and 0.9% within populations and 0.5 to 1.9% between populations. The largest genetic distance was the 1.9% between the ChangJiang and MinJiang populations, and the smallest was 0.5% between the MinJiang and the ZhuJiang populations. AMOVA analysis disclosed that variation among populations accounts for 74.61% of total variation, suggesting that this is the main source of total variation. The results of this study suggest that the three Coilia mystus populations, especially the most isolated Changjiang population, have developed significant genetic structure.  相似文献   

12.
13.
Gur'ev VP  Blinov AG 《Genetika》2002,38(3):310-315
In eight Holarctic populations of two typical chironomid sibling species of the plumosus group, Chrionomus entis and Chironomus plumosus, nucleotides sequences of mitochondrial (cytb) and nuclear (gb2b) gene regions were examined. The phylogenetic trees reflecting the evolutionary histories of the nuclear and mitochondrial markers exhibited significant differences. On the tree based on the nuclear gene sequences the populations clustered according to their species affiliation, whereas on the tree based on the mitochondrial gene sequences the populations were grouped according to their geographic position. This discrepancy is probably explained by mitochondrial gene flow between sympatric species with incomplete reproductive isolation (sibling species). Based on our results together with the earlier data on nuclear and mitochondrial gene sequences of some other species from the phylogenetic group plumosus, a scheme of phylogenetic relationships within this group is proposed. This scheme is in many ways different from the traditional view on the evolutionary relationships among species of the plumosus group.  相似文献   

14.
We investigated the phylogenetic relationships and estimated the historical demography of the Japanese fire-bellied newt, Cynops pyrrhogaster, from Japanese mainlands using 1407-bp sequences of the mitochondrial DNA (NADH6, tRNAglu, cyt b) and 1208-bp sequences of nuclear DNA (Rag-1) genes. Phylogenetic trees based on mitochondrial DNA revealed four major haplotype clades (NORTHERN, CENTRAL, WESTERN, and SOUTHERN clades) within this species. Degree of genetic differentiation among major haplotype clades was very large for intraspecific variation, suggesting this species to be composed of four species lineages that replace each other geographically. Nuclear genetic variation presented no obvious patterns of geographic structure except for the distinctness of populations diagnosed by NORTHERN clade of mitochondrial haplotypes, suggesting results of incomplete lineage sorting. Current distribution and estimated divergence times for the genus Cynops suggest that the common ancestor of two Japanese species (C. pyrrhogaster and C. ensicauda from the Ryukyu Islands) had diverged at the edge of the continent corresponding to the present East China Sea and Central Ryukyus. Subsequent range expansion to Japanese mainland seems to have occurred in the middle Miocene. Population-genetic analyses indicated that all species lineages, except for the SOUTHERN one, experienced geographic population reductions and expansions associated with glacial and postglacial climatic oscillations.  相似文献   

15.
The complete mitochondrial genomes of the parasitic trematodes Opisthorchis felineus and Clonorchis sinensis (family Opisthorchiidae) were fully sequenced in order to develop markers for DNA diagnostics of the liver flukes infection, molecular ecology, population and phylogenetic studies. The complete sequences of mitochondrial genomes of these species comprise 14,277 and 13,875 bp, respectively, and are thus the shortest trematode mitochondrial genomes sequenced to date. The gene content and arrangement are identical to that of Fasciola hepatica. ATG and GTG are used as the start-codons and TAG and TAA are used as the stop-codons. The stop-codon TAG of the C. sinensis nad1 gene overlap by 1 nt with the downstream tRNA-Asn gene. Alternative structures for the Ser(UCN) tRNAs were found for both species. The noncoding control regions are separated into two parts by the tRNA-Gly gene and contain neither tandem repeats, which are characteristic for trematode control regions, nor secondary structures. In conclusion, the complete mitochondrial DNA sequences of O. felineus and C. sinensis will serve as a resource for comparative mitochondrial genomics and systematic studies of parasitic trematodes.  相似文献   

16.
We determined complete mitochondrial DNA sequences of the two yeast species, Candida orthopsilosis and Candida metapsilosis, and compared them with the linear mitochondrial genome of their close relative, C.parapsilosis. Mitochondria of all the three species harbor compact genomes encoding the same set of genes arranged in the identical order. Differences in the length of these genomes result mainly from the presence/absence of introns. Multiple alterations were identified also in the sequences of the ribosomal and transfer RNAs, and proteins. However, the most striking feature of C.orthopsilosis and C.metapsilosis is the existence of strains differing in the molecular form of the mitochondrial genome (circular-mapping versus linear). Their analysis opens a unique window for understanding the role of mitochondrial telomeres in the stability and evolution of molecular architecture of the genome. Our results indicate that the circular-mapping mitochondrial genome derived from the linear form by intramolecular end-to-end fusions. Moreover, we suggest that the linear mitochondrial genome evolved from a circular-mapping form present in a common ancestor of the three species and, at the same time, the emergence of mitochondrial telomeres enabled the formation of linear monomeric DNA forms. In addition, comparison of isogenic C.metapsilosis strains differing in the form of the organellar genome suggests a possibility that, under some circumstances, the linearity and/or the presence of telomeres provide a competitive advantage over a circular-mapping mitochondrial genome.  相似文献   

17.
Crematogaster fraxatrix Forel, 1911 and two new species, C. chhangi sp. n. and C. simboloni sp. n., are described from Cambodia and Indonesia, respectively. DNA sequences were generated for C. fraxarix and the two newly described species using 3 amplications of two regions of the mitochondrial gene COI with a total of 1129 bp. The mean interspecific divergences are 9.4% and 23.5% for C. fraxatrix vs. C. chhangi, C. simboloni, respectively. DNA sequences reveal that C. simboloni is found to be genetically distinct from the other two species, but C. chhangi is not distinct from C. fraxatrix.  相似文献   

18.
采用最大似然法、贝叶斯法、最大简约法对来自角蟾科Megophryidae(Anura)9属20种及外群2种共30号标本的DNA序列进行了系统发育分析,所用片段为线粒体16S rRNA和cytb基因部分序列。结果表明,用于分析的所有角蟾科物种形成两大支。Ophryophryne、Brachycarsophrys、Atympanophrys同属第一支,前两者的系统关系较近。第二支5属间系统发育关系为(Leptolalax,((Leptobrachium,Vibrissaphora),(Oreolalax,Scutiger)))。  相似文献   

19.
Complete 12S rRNA and partial cytochrome b (cytb) gene sequences have been obtained from museum samples of two recently extinct potoroids-Potorous platyops and Caloprymnus campestris. Phylogenetic analyses based on these mitochondrial DNA sequences suggest that the broad-faced potoroo (P. platyops) was a close relative of the recently discovered Potorous longipes and the recently re-discovered Potorous gilberti. Although the extinct desert rat-kangaroo (C. campestris) was clearly resolved as a member of the subfamily Potoroinae, its precise relationships vis a vis other living potoroines are unclear. We confirmed that the rufous rat-kangaroo (Aepyprymnus rufescens) is sister to all living Bettongia species, but the molecular data provide no support for a sister relationship between A. rufescens and C. campestris as suggested by on the basis of four shared morphological characters. Molecular dating analyses suggest that the initial radiation of potoroinae seems to have occurred soon after its origin in the early Miocene. Within Potoroinae, C. campestris diverged from other taxa approximately 16 million years ago. P. platyops diverged from P. longipes+P. gilberti approximately 14-15 million years ago.  相似文献   

20.
We analysed 131 common impala (Aepyceros melampus melampus) samples from two provinces in South Africa (Limpopo and KwaZulu‐Natal) that are separated by the Drakensberg Mountain Range using sequences of the mitochondrial control region and seven polymorphic nuclear microsatellite loci. In line with earlier studies on bovid species, we found very high values of genetic diversity, particularly at the mtDNA locus with an overall nucleotide diversity of 3.6% and an overall haplotype diversity of 0.98. All statistical approaches confirmed a significant population differentiation between Limpopo and KwaZulu‐Natal, suggesting that areas of unsuitable habitat caused by the presence of the Drakensberg Range and the Indian Ocean coastal belt act as a barrier to gene flow. Only few individuals with signs of admixed origin were indicative of translocations or rare migration between the two provinces. Combination of our mtDNA data set with those of previous studies on impala from south‐western, southern and eastern Africa revealed the highest diversity in South Africa. This is in line with the hypothesis of a southern glacial refuge from which various African ungulate species spread northeast during the Holocene, although in the case of impala further analyses based on larger data sets will be necessary to definitively settle this question.  相似文献   

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