期刊文献+
共找到2,332篇文章
< 1 2 117 >
每页显示 20 50 100
Gene characterization and phylogenetic analysis of four mitochondrial genomes in Caenogastropoda
1
作者 Jiangyong Qu Wanqi Yang +7 位作者 Xindong Teng Li Xu Dachuan Zhang Zhikai Xing Shuang Wang Xiumei Liu Lijun Wang Xumin Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第2期137-150,共14页
Caenogastropoda is a highly diverse group,containing~60%of all existing gastropods.Species in this subclass predominantly inhabit marine environments and have a high ecological and economic value.Owing to the increase... Caenogastropoda is a highly diverse group,containing~60%of all existing gastropods.Species in this subclass predominantly inhabit marine environments and have a high ecological and economic value.Owing to the increase in relevant phylogenetic studies,our understanding of between species relatedness in Caenogastropoda has improved.However,the biodiversity,taxonomic status,and phylogenetic relationships of this group remain unclear.In the present study,we performed next-generation sequencing of four complete mitochondrial genomes from three families(Buccinidae,Columbellidae,and Cypraeidae)and the four mitogenomes were classical circular structures,with a length of 16177 bp in Volutharpa ampullacea,16244 bp in Mitrella albuginosa,16926bp in Mauritia arabica asiatica and 15422 bp in Erronea errones.Base composition analysis indicated that whole sequences were biased toward A and T.Then compared them with 171 complete mitochondrial genomes of Caenogastropoda.The phylogenetic relationship of Caenogastropoda derived from Maximum Likelihood(ML)and Bayesian Inference(BI)trees constructed based on CDS sequences was consistent with the results of traditional morphological analysis,with all three families showing close relationships.This study supported Caenogastropoda at the molecular level as a separate clade of Mollusca.According to our divergence time estimations,Caenogastropoda was formed during the middle Triassic period(~247.2–237 Ma).Our novel mitochondrial genomes provide evidence for the speciation of Caenogastropoda in addition to elucidating the mitochondrial genomic evolution of this subclass. 展开更多
关键词 mitochondrial genome phylogenetic analysis CAENOGASTROPODA
下载PDF
Molecular phylogenetic relationships based on mitochondrial genomes of novel deep-sea corals(Octocorallia:Alcyonacea):Insights into slow evolution and adaptation to extreme deep-sea environments
2
作者 Zhan-Fei Wei Kai-Wen Ta +6 位作者 Nan-Nan Zhang Shan-Shan Liu Liang Meng Kai-Qiang Liu Chong-Yang Cai Xiao-Tong Peng Chang-Wei Shao 《Zoological Research》 SCIE CSCD 2024年第1期215-225,共11页
A total of 10 specimens of Alcyonacea corals were collected at depths ranging from 905 m to 1633 m by the manned submersible Shenhai Yongshi during two cruises in the South China Sea(SCS).Based on mitochondrial genomi... A total of 10 specimens of Alcyonacea corals were collected at depths ranging from 905 m to 1633 m by the manned submersible Shenhai Yongshi during two cruises in the South China Sea(SCS).Based on mitochondrial genomic characteristics,morphological examination,and sclerite scanning electron microscopy,the samples were categorized into four suborders(Calcaxonia,Holaxonia,Scleraxonia,and Stolonifera),and identified as 9 possible new cold-water coral species.Assessments of GC-skew dissimilarity,phylogenetic distance,and average nucleotide identity(ANI)revealed a slow evolutionary rate for the octocoral mitochondrial sequences.The nonsynonymous(Ka)to synonymous(Ks)substitution ratio(Ka/Ks)suggested that the 14 protein-coding genes(PCGs)were under purifying selection,likely due to specific deep-sea environmental pressures.Correlation analysis of the median Ka/Ks values of five gene families and environmental factors indicated that the genes encoding cytochrome b(cyt b)and DNA mismatch repair protein(mutS)may be influenced by environmental factors in the context of deep-sea species formation.This study highlights the slow evolutionary pace and adaptive mechanisms of deep-sea corals. 展开更多
关键词 Mitochondrial genome Alcyonacea Ka/Ks evolution Environmental factors
下载PDF
CRISPR-Based Technologies for the Manipulation of Eukaryotic Genomes
3
作者 Alexis C Komor 《四川生理科学杂志》 2024年第1期160-160,共1页
The CRISPR-Cas9 RNA-guided DNA endonuclease has contributed to an explosion of advances in the life sciences that have grown from the ability to edit genomes within living cells.In this Review,we summarize CRISPR-base... The CRISPR-Cas9 RNA-guided DNA endonuclease has contributed to an explosion of advances in the life sciences that have grown from the ability to edit genomes within living cells.In this Review,we summarize CRISPR-based technologies that enable mammalian genome editing and their various applications. 展开更多
关键词 CRISPR Cas9 GENOME
下载PDF
Evolutionary genetics of wheat mitochondrial genomes
4
作者 Hui-Lin Hu Fan Zhang +1 位作者 Pei Wang Fu-Hao Lu 《The Crop Journal》 SCIE CSCD 2023年第6期1774-1781,共8页
The Triticum-Aegilops complex provides ideal models for the study of polyploidization,and mitochondrial genomes(mtDNA)can be used to trace cytoplasmic inheritance and energy production following polyploidization.In th... The Triticum-Aegilops complex provides ideal models for the study of polyploidization,and mitochondrial genomes(mtDNA)can be used to trace cytoplasmic inheritance and energy production following polyploidization.In this study,gapless mitochondrial genomes for 19 accessions of five Triticum or Aegilops species were assembled.Comparative genomics confirmed that the BB-genome progenitor donated mtDNA to tetraploid T.turgidum(genome formula AABB),and that this mtDNA was then passed on to the hexaploid T.aestivum(AABBDD).T urartu(AA)was the paternal parent of T.timopheevii(AAGG),and an earlier Ae.tauschii(DD)was the maternal parent of Ae.cylindrica(CCDD).Genic sequences were highly conserved within species,but frequent rearrangements and nuclear or chloroplast DNA insertions occurred during speciation.Four highly variable mitochondrial genes(atp6,cob,nad6,and nad9)were established as marker genes for Triticum and Aegilops species identification.The BB/GG-specific atp6 and cob genes,which were imported from the nuclear genome,could facilitate identification of their diploid progenitors.Genic haplotypes and repeat-sequence patterns indicated that BB was much closer to GG than to Ae.speltoides(SS).These findings provide novel insights into the polyploid evolution of the Triticum/Aegilops complex from the perspective of mtDNA,advancing understanding of energy supply and adaptation in wheat species。 展开更多
关键词 WHEAT MITOCHONDRION MTDNA Comparative genomics POLYPLOIDIZATION
下载PDF
Characterization and Phylogenetic Implications of the Complete Mitogenomes of Two Species in the Genus Zhangixalus(Anura:Rhacophoridae)
5
作者 Lichun JIANG Wanqing SONG +5 位作者 Yujia LIU Yujie ZHANG Jingfeng LIU Chunxiu LIU Xiaodong JIA Wei CHEN 《Asian Herpetological Research》 SCIE CSCD 2023年第3期191-211,共21页
Mitochondrial genomes(mitogenomes)in frogs are essential for reconstructing the phylogenetic relationships and shedding light on the molecular evolution in these animals.However,there are only seven complete Rhacophor... Mitochondrial genomes(mitogenomes)in frogs are essential for reconstructing the phylogenetic relationships and shedding light on the molecular evolution in these animals.However,there are only seven complete Rhacophoridae genomes that have been reported to date.In this paper,two complete mitogenomes of the Chinese whipping frog(Zhangixalus chenfui)and Emei tree frog(Z.omeimontis)were described,each of which was 20520 and 19782 bp in size,and had A+T contents of 64.26%and 63.83%.The two mitogenomes each included two non-coding control region(D-loop,CR),two ribosomal RNA genes(rRNAs),13 protein-coding genes(PCGs),and 22 transfer RNA genes(tRNAs),and it was found that the mitogenome of Z.chenfui also includes three tandem tRNAMet gene sequences.A typical clover-leaf structure was found for all tRNAs except for tRNASer1(AGN),which showed a reduced DHU arm.The putative D-loop region contains multiple types of tandem repeats regions.Both of these two mitogenomes showed similar pattern of gene rearrangement(tRNA-Ser-ND6-tRNA-Glu-CytbCR1-ND5-CR2-tRNA-Thr-tRNA-Leu-tRNA-Pro).Additionally,three consecutive tRNAMet genes were found for the first time in Z.chenfui,a species in the Rhacophoridae family.For all phylogenetic analyses,which were based on 13 protein-coding genes from 91 Ranoidea mitogenomes,the same phylogenetic trees were observed using either maximum likelihood or Bayesian approaches.These results suggest that the phylogenetic hypotheses for the Ranoidea(including Rhacophoridae,Mantellidae,Ranidae and Dicroglossidae)derived from these mitogenomic data could provide substantiation for the relationships of(Dicroglossidae(Ranidae,(Mantellidae,Rhacophoridae))),and support the presence of a monophyletic group in four families.Moreover,Z.omeimontis and Z.dennysi were found to cluster on the same branch,indicating that they were more closely related as a group.This group may in turn form sister groups with Z.arboreus and Z.schlegelii.However,Z.chenfui is located on the base of other species in the genera.Increased mitogenome sampling should be conducted to provide a more satisfactory resolution to the phylogeny of the Rhacophorus,Rhacophoridae,and Mantellidae. 展开更多
关键词 mitochondrial genome PHYLOGENY Ranoidea Rhacophoridae Zhangixalus chenfui Z.omeimontis
下载PDF
Evolutionary relationships of mitogenomes in a recently radiated Old World avian family
6
作者 Wenqing Zang Zhiyong Jiang +5 位作者 Per G.P.Ericson Gang Song Sergei VDrovetski Takema Saitoh Fumin Lei Yanhua Qu 《Avian Research》 SCIE CSCD 2023年第2期153-159,共7页
Environmentally heterogeneous mountains provide opportunities for rapid diversification and speciation.The family Prunellidae(accentors)is a group of birds comprising primarily mountain specialists that have recently ... Environmentally heterogeneous mountains provide opportunities for rapid diversification and speciation.The family Prunellidae(accentors)is a group of birds comprising primarily mountain specialists that have recently radiated across the Palearctic region.This rapid diversification poses challenges to resolving their phylogeny.Herein we sequenced the complete mitogenomes and estimated the phylogeny using all 12(including 28 individuals)currently recognized species of Prunellidae.We reconstructed the mitochondrial genome phylogeny using 13 protein-coding genes of 12 species and 2 Eurasian Tree Sparrows(Passer montanus).Phylogenetic relationships were estimated using a suite of analyses:maximum likelihood,maximum parsimony and the coalescent-based SVDquartets.Divergence times were estimated by implementing a Bayesian relaxed clock model in BEAST2.Based on the BEAST time-calibrated tree,we implemented an ancestral area reconstruction using RASP v.4.3.Our phylogenies based on the maximum likelihood,maximum parsimony and SVDquartets approaches support a clade of large-sized accentors(subgenus Laiscopus)to be sister to all other accentors with small size(subgenus Prunella).In addition,the trees also support the sister relationship of P.immaculata and P.rubeculoides+P.atrogularis with 100%bootstrap support,but the relationships among the remaining eight species in the Prunella clade are poorly resolved.These species cluster in different positions in the three phylogenetic trees and the nodes are often poorly supported.The five nodes separating the seven species diverged simultaneously within less than half million years(i.e.,between 2.71 and 3.15 million years ago),suggesting that the recent radiation is likely responsible for rampant incomplete lineage sorting and gene tree conflicts.Ancestral area reconstruction indicates a central Palearctic region origin for Prunellidae.Our study highlights that whole mitochondrial genome phylogeny can resolve major lineages within Prunellidae but is not sufficient to fully resolve the relationship among the species in the Prunella clade that almost simultaneously diversify during a short time period.Our results emphasize the challenge to reconstruct reliable phylogenetic relationship in a group of recently radiated species. 展开更多
关键词 Incomplete lineage sorting Mitochondrial genome Mountain specialists RADIATION
下载PDF
Assembly and phylogenomic analysis of cotton mitochondrial genomes provide insights into the history of cotton evolution
7
作者 Yanlei Feng Yukang Wang +10 位作者 Hejun Lu Jun Li Delara Akhter Fang Liu Ting Zhao Xingxing Shen Xiaobo Li James Whelan Tianzhen Zhang Jianping Hu Ronghui Pan 《The Crop Journal》 SCIE CSCD 2023年第6期1782-1792,共11页
Cotton is a major crop that provides the most important renewable textile fibers in the world.Studies of the taxonomy and evolution of cotton species have received wide attentions,not only due to cotton’s economic va... Cotton is a major crop that provides the most important renewable textile fibers in the world.Studies of the taxonomy and evolution of cotton species have received wide attentions,not only due to cotton’s economic value but also due to the fact that Gossypium is an ideal model system to study the origin,evolution,and cultivation of polyploid species.Previous studies suggested the involvement of mitochondrial genome editing sites and copy number as well as mitochondrial functions in cotton fiber elongation.Whereas,with only a few mitogenomes assembled in the cotton genus Gossypium,our knowledge about their roles in cotton evolution and speciation is still scarce.To close this gap,here we assembled 20 mitogenomes from 15 cotton species spanning all the cotton clades(A–G,K,and AD genomes)and 5 cotton relatives using short and long sequencing reads.Systematic analyses uncovered a high level of mitochondrial gene sequence conservation,abundant sequence repeats and many insertions of foreign sequences,as well as extensive structural variations in cotton mitogenomes.The sequence repeats and foreign sequences caused significant mitogenome size inflation in Gossypium and its close relative Kokia in general,while there is no significant difference between the lint and fuzz cotton mitogenomes in terms of gene content,RNA editing,and gene expression level.Interestingly,we further revealed the specific presence and expression of two novel mitochondrial open reading frames(ORFs)in lint-fiber cotton species.Finally,these structural features and novel ORFs help us gain valuable insights into the history of cotton evolution and polyploidization and the origin of species producing long lint fibers from a mitogenomic perspective. 展开更多
关键词 Cotton evolution Cotton phylogeny Lint fiber cotton Mitochondrial genome Mitochondrial genes
下载PDF
Evolutionary timescale of chalcidoid wasps inferred from over one hundred mitochondrial genomes
8
作者 Jia-Chen Zhu Hui Xiao +8 位作者 Pu Tang Xiao-Fei Li Xuan-Kun Li Chao-Dong Zhu Qiong Wu Jin-Hua Xiao Cornelis van Achterberg Da-Wei Huang Xue-Xin Chen 《Zoological Research》 SCIE CAS CSCD 2023年第3期467-482,共16页
Chalcidoidea is one of the most biologically diverse groups among Hymenoptera.Members are characterized by extraordinary parasitic lifestyles and extensive host ranges,among which several species attack plants or serv... Chalcidoidea is one of the most biologically diverse groups among Hymenoptera.Members are characterized by extraordinary parasitic lifestyles and extensive host ranges,among which several species attack plants or serve as pollinators.However,higher-level chalcidoid relationships remain controversial.Here,we performed mitochondrial phylogenomic analyses for major clades(18out of 25 families)of Chalcidoidea based on 139 mitochondrial genomes.The compositional heterogeneity and conflicting backbone relationships in Chalcidoidea were assessed using various datasets and tree inferences.Our phylogenetic results supported the monophyly of 16families and polyphyly of Aphelinidae and Pteromalidae.Our preferred topology recovered the relationship(Mymaridae+(Signiphoridae+Leucospidae)+(Chalcididae+((Perilampidae+Eucharitidae)+remaining Chalcidoidea))).The monophyly of Agaonidae and Sycophaginae was rejected,while the gall-associated((Megastigmidae+Ormyridae)+(Ormocerinae+Eurytomidae))relationship was supported in most results.A six-gene inversion may be a synapomorphy for most families,whereas other derived gene orders may introduce confusion in phylogenetic signals at deeper nodes.Dating estimates suggested that Chalcidoidea arose near the Jurassic/Cretaceous boundary and that two dynamic shifts in diversification occurred during the evolution of Chalcidoidea.We hypothesized that the potential codiversification between chalcidoids and their hosts may be crucial for accelerating the diversification of Chalcidoidea.Ancestral state reconstruction analyses supported the hypothesis that gallinducers were mainly derived from parasitoids of gallinducers,while other gall-inducers were derived from phytophagous groups.Taken together,these findings advance our understanding of mitochondrial genome evolution in the major interfamilial phylogeny of Chalcidoidea. 展开更多
关键词 Mitochondrial genome CHALCIDOIDEA Compositional heterogeneity Divergence time Evolution of host and gall associations
下载PDF
Three New Ranidae Mitogenomes and the Evolution of Mitochondrial Gene Rearrangements among Ranidae Species 被引量:1
9
作者 Jiandong YANG Jiaojiao YU +3 位作者 Jiabin LIU Ming ZHOU Biao LI Bo OUYANG 《Asian Herpetological Research》 SCIE CSCD 2018年第2期85-98,共14页
Various types of gene rearrangements have been discovered in the mitogenoes of the frog family Ranidae. In this study, we determined the complete mitogenome sequence of three Rana frogs. By combining the available mit... Various types of gene rearrangements have been discovered in the mitogenoes of the frog family Ranidae. In this study, we determined the complete mitogenome sequence of three Rana frogs. By combining the available mitogenomic data sets from GenBank, we evaluated the phylogenetic relationships of Ranidae at the mitogenome level and analyzed mitogenome rearrangement cases within Ranidae. The three frogs shared an identical mitogenome organization that was extremely similar to the typical Neobatrachian-type arrangement. Except for the genus Babina, the monophyly of each genus was well supported. The genus Amnirana occupied the most basal position among the Ranidae. The [Lithobates + Rana] was the closest sister group of Odorrana. The diversity of mitochondrial gene arrangements in ranid species was unexpectedly high, with 47 mitogenomes from 40 ranids being classified into 10 different gene rearrangement types. Some taxa owned their unique gene rearrangement characteristics, which had significant implication for their phylogeny analysis. All rearrangement events discovered in the Ranidae mitogenomes can be explained by the duplication and random loss model. 展开更多
关键词 mitochondrial genomes gene rearrangement molecular phylogeny RANIDAE
下载PDF
Current status and future perspectives for sequencing livestock genomes 被引量:1
10
作者 Yongsheng Bai Maureen Sartor James Cavalcoli 《Journal of Animal Science and Biotechnology》 SCIE CAS 2012年第1期10-15,共6页
Only in recent years, the draft sequences for several agricultural animals have been assembled. Assembling an individual animal's entire genome sequence or specific region(s) of interest is increasingly important f... Only in recent years, the draft sequences for several agricultural animals have been assembled. Assembling an individual animal's entire genome sequence or specific region(s) of interest is increasingly important for agricultura researchers to perform genetic comparisons between animals with different performance. We review the current status for several sequenced agricultural species and suggest that next generation sequencing (NGS) technology with decreased sequencing cost and increased speed of sequencing can benefit agricultural researchers. By taking advantage of advanced NGS technologies, genes and chromosomal regions that are more labile to the influence of environmental factors could be pinpointed. A more long term goal would be addressing the question of how animals respond at the molecular and cellular levels to different environmental models (e.g. nutrition). Upon revealing important genes and gene-environment interactions, the rate of genetic improvement can also be accelerated. It is clear that NGS technologies will be able to assist animal scientists to efficiently raise animals and to better prevent infectious diseases so that overall costs of animal production can be decreased. 展开更多
关键词 livestock genomes next-generation sequencing technology NUTRITION
下载PDF
Simulation for chaos game representation of genomes by recurrent iterated function systems 被引量:1
11
作者 Zu-Guo Yu Long Shi +1 位作者 Qian-Jun Xiao Vo Anh 《Journal of Biomedical Science and Engineering》 2008年第1期44-51,共8页
Chaos game representation (CGR) of DNA sequences and linked protein sequences from genomes was proposed by Jeffrey (1990) and Yu et al. (2004), respectively. In this paper, we consider the CGR of three kinds of sequen... Chaos game representation (CGR) of DNA sequences and linked protein sequences from genomes was proposed by Jeffrey (1990) and Yu et al. (2004), respectively. In this paper, we consider the CGR of three kinds of sequences from complete genomes: whole genome DNA sequences, linked coding DNA sequences and linked protein sequences. Some fractal patterns are found in these CGRs. A recurrent iterated function systems (RIFS) model is proposed to simulate the CGRs of these sequences from genomes and their induced measures. Numerical results on 50 genomes show that the RIFS model can simulate very well the CGRs and their induced measures. The parameters estimated in the RIFS model reflect information on species classification. 展开更多
关键词 genomes CHAOS GAME REPRESENTATION RECURRENT ITERATED function systems.
下载PDF
Distribution of Triplet Separators in Bacterial Genomes
12
作者 HU Rui ZHENG Wei-Mou 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第7期115-118,共4页
Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared w... Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared with the distributions of the bacterial genomes. A prominent double band structure, which does not exist in the theoretical distributions, is observed in the bacterial distributions for most triplets. 展开更多
关键词 BACTERIAL genomes DNA SEQUENCE analysis
下载PDF
Analysis of the chloroplast genomes of four Pinus species in Northeast China:Insights into hybrid speciation and identification of DNA molecular markers
13
作者 Tao Yu Zhiyuan Jia +5 位作者 Buddhi Dayananda Junqing Li Xiaolei Guo Liang Shi Xiaowen Yuan Yan Gao 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第6期1881-1890,共10页
Species of the Pinus genus provide a classical model for studying hybrid speciation.Although studies on two narrowly distributed species(P inus funebris and P.takahasii)concluded that they originated from two widespre... Species of the Pinus genus provide a classical model for studying hybrid speciation.Although studies on two narrowly distributed species(P inus funebris and P.takahasii)concluded that they originated from two widespread species(P.sylvestris and P.densiflora)via hybrid speciation,the conclusion was based on a low number of informative restriction sites.In this study,we analyzed the sequences of four Pinus chloroplast(cp)genomes(P.sylvestris,P.densiflora,P.funebris and P.takahasii)to clarify whether hybrid speciation was involved.The complete cp-genomes of Pinus species ranged in size from 119,865 to 119,890 bp,similar to other Pinus species.Phylogenetic results based on the whole cp-genomes showed P.sylvestris clustered with P.funebris and P.takahasii,which suggested that P.sylvestris was the paternal parent in hybridization events.In an analysis of simple sequence repeats(SSRs),we detected a total of 69 SSRs repeats among the four Pinus cp-genomes;most were A or T bases.In addition,we identified divergent hotspot regions among the four Pinus cp-genomes(trnE-clpP,cemA-ycf4,petD-rpoA,psbD-trnT,and trnN-chlL),in P.sylvestris(psbD-trnT,trnN-chlL,psbB and rps8)and in P.densiflora(trnE-clpP,petD-rpoA,ycf3 intron,psbD-trnT,and trnN-chlL).The genome information found in this study provides new insights into hybrid speciation in P inus and contributes to a better understanding of the phylogenetic relationships within the Pinus genus. 展开更多
关键词 PINUS Chloroplast genomes Hybrid speciation Divergence hotspot regions Phylogenetic relationship
下载PDF
Discrete Circular Distributions with Applications to Shared Orthologs of Paired Circular Genomes
14
作者 Tomoaki Imoto Grace S.Shieh Kunio Shimizu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第6期1131-1149,共19页
For structural comparisons of paired prokaryotic genomes,an important topic in synthetic and evolutionary biology,the locations of shared orthologous genes(henceforth orthologs)are observed as binned data.This and oth... For structural comparisons of paired prokaryotic genomes,an important topic in synthetic and evolutionary biology,the locations of shared orthologous genes(henceforth orthologs)are observed as binned data.This and other data,e.g.,wind directions recorded at monitoring sites and intensive care unit arrival times on the 24-hour clock,are counted in binned circular arcs,thus modeling them by discrete circular distributions(DCDs)is required.We propose a novel method to construct a DCD from a base continuous circular distribution(CCD).The probability mass function is defined to take the normalized values of the probability density function at some pre-fixed equidistant points on the circle.Five families of constructed DCDs which have normalizing constants in closed form are presented.Simulation studies show that DCDs outperform the corresponding CCDs in modeling grouped(discrete)circular data,and minimum chi-square estimation outperforms maximum likelihood estimation for parameters.We apply the constructed DCDs,invariant wrapped Poisson and wrapped discrete skew Laplace to compare the structures of paired bacterial genomes.Specifically,discrete four-parameter wrapped Cauchy(nonnegative trigonometric sums)distribution models multi-modal shared orthologs in Clostridium(Sulfolobus)better than the others considered,in terms of AIC and Freedman’s goodness-of-fit test.The result that different DCDs fit the shared orthologs is consistent with the fact they belong to two kingdoms.Nevertheless,these prokaryotes have a common favored site around 70°on the unit circle;this finding is important for building synthetic prokaryotic genomes in synthetic biology.These DCDs can also be applied to other binned circular data. 展开更多
关键词 Bacterial genomes circular distribution goodness-of-fit test modeling synthetic and evolutionary biology.
下载PDF
T4SP: A Novel Tool and Database for Type IV Secretion Systems in Bacterial Genomes
15
作者 ZHANG Wen YU Wei Wen +5 位作者 LIU Di LI Ming DU Peng Cheng WU Yi Lei George F. GAO CHEN Chen 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第7期614-617,共4页
Secretion systems, macromolecules to pass which can mediate the across cellular membranes, are essential for virulent and genetic material exchange among bacterial species[1]. Type IV secretion system (T4SS) is one ... Secretion systems, macromolecules to pass which can mediate the across cellular membranes, are essential for virulent and genetic material exchange among bacterial species[1]. Type IV secretion system (T4SS) is one of the secretion systems and it usually consists of 12 genes: VirB1, VirB2 ...VirB11, and VirD4[2]. The structure and molecular mechanisms of these genes have been well analyzed in Gram-negative strains[3] and Gram-positive strains were once believed to be lack of T4SS. However, some recent studies revealed that one or more virB/D genes also exist in some kinds of Gram-positive bacteria and play similar role, and form a T4SS-like system[3]. The VirBl-like, VirB4, VirB6, and VirD4 genes were identified in the chromosome of Gram-positive bacterium Streptococcus suis in our previous studies and their role as important mobile elements for horizontal transfer to recipients in an 89 K pathogenicity island (PAl) was demonstrated[45]. However, their structure and molecular mechanisms in other strains, especially in Gram-positive strains, are remained unclear. 展开更多
关键词 T4SP A Novel Tool and Database for Type IV Secretion Systems in Bacterial genomes
下载PDF
Establishment of transgenic mouse harboring hepatitis B virus (adr subtype) genomes 被引量:9
16
作者 Yi Ping Hu1 Wei Jiang Hu1 +7 位作者 Wen Chao Zheng2 Jian Xiu Li1 De Shun Dai1 Xin Min Wang1 Shu Zhong Zhang1 Hong Yu Yu3 Wei Sun4 Guang Rong Hao4 1Department of Cell Biology, Second Military Medical University, Shanghai 200433, China2University of Wisconsin, Madison, WI 53705, USA3Department of Pathology, Second Military Medical University, Shanghai 200433, China4Center of laboratory Animals, Second Military Medical University, Shanghai 200433, China 《World Journal of Gastroenterology》 SCIE CAS CSCD 2001年第1期111-114,共4页
INTRODUCTIONHepatitis B virus (HBV) belongs to the group ofhepatovirus, a major pathogen of human acute andchronic hepatitis B[1 4], which has a very closeassociation with human hepatocellular carcinoma(HCC)[5-8], For... INTRODUCTIONHepatitis B virus (HBV) belongs to the group ofhepatovirus, a major pathogen of human acute andchronic hepatitis B[1 4], which has a very closeassociation with human hepatocellular carcinoma(HCC)[5-8], For example, a statistical data from ahospital in Shanghai showed that 80% of HCCpatients were positive for HBsAg ( personalcommunication). 展开更多
关键词 hepatitis B virus micetransgenic genome POLYMERASE chain reaction IMMUNOHISTOCHEMISTRY microscopy electron danesparticles
下载PDF
Zea mays(L.) P1 locus for cob glume color identified as a post-domestication selection target with an effect on temperate maize genomes 被引量:6
17
作者 Chuanxiao Xie Jianfeng Weng +9 位作者 Wenguo Liu Cheng Zou Zhuanfang Hao Wenxue Li Minshun Li Xiaosen Guo Gengyun Zhang Yunbi Xu Xinhai Li Shihuang Zhang 《The Crop Journal》 SCIE CAS 2013年第1期15-24,共10页
Artificial selection during domestication and post-domestication improvement results in loss of genetic diversity near target loci. However, the genetic locus associated with cob glume color and the nature of the geno... Artificial selection during domestication and post-domestication improvement results in loss of genetic diversity near target loci. However, the genetic locus associated with cob glume color and the nature of the genomic pattern surrounding it was elusive and the selection effect in that region was not clear. An association mapping panel consisting of 283 diverse modern temperate maize elite lines was genotyped by a chip containing over 55,000 evenly distributed SNPs. Ten-fold resequencing at the target region on 40 of the panel lines and 47 tropical lines was also undertaken. A genome-wide association study(GWAS) for cob glume color confirmed the P1 locus, which is located on the short arm of chromosome 1, with a-log10 P value for surrounding SNPs higher than the Bonferroni threshold(α/n, α < 0.001) when a mixed linear model(MLM) was implemented. A total of 26 markers were identified in a 0.78 Mb region surrounding the P1 locus, including 0.73 Mb and 0.05 Mb upstream and downstream of the P1 gene, respectively. A clear linkage disequilibrium(LD) block was found and LD decayed very rapidly with increasing physical distance surrounding the P1 locus. The estimates of π and Tajima's D were significantly(P < 0.001) lower at both ends compared to the locus. Upon comparison of temperate and tropical lines at much finer resolution by resequencing(180-fold finer than chip SNPs), a more structured LD block pattern was found among the 40 resequenced temperate lines. All evidence indicates that the P1 locus in temperate maize has not undergone neutral evolution but has been subjected to artificial selection during post-domestication selection or improvement. The information and analytical results generated in this study provide insights as to how breeding efforts have affected genome evolution in crop plants. 展开更多
关键词 Genome-wide association study Artificial SELECTION Linkage disequilibrium Crop genome evolution
下载PDF
A Comparative Analysis of the Chloroplast Genomes of Four Salvia Medicinal Plants 被引量:6
18
作者 Conglian Liang Lei Wang +11 位作者 Juan Lei Baozhong Duan Weisi Ma Shuiming Xiao Haijun Qi Zhen Wang Yaoqi Liu Xiaofeng Shen Shuai Guo Haoyu Hu Jiang Xu Shilin Chen 《Engineering》 SCIE EI 2019年第5期907-915,共9页
Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it int... Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it into wider usage within the field of medicine.Salvia Linn.(S.Linn.)is a large genus of Labiatae that includes important medicinal plants.In this herbgenomics study,the complete chloroplast(cp)genomes of two Salvia spp.—namely,S.przewalskii and S.bulleyana,which are used as a surrogate for S.miltiorrhiza—were sequenced and compared with those of two other reported Salvia spp.—namely,S.miltiorrhiza and S.japonica.The genome organization,gene number,type,and repeat sequences were compared.The annotation results showed that both Salvia plants contain 114 unique genes,including 80 protein-coding,30 transfer RNA(tRNA),and four ribosomal RNA(rRNA)genes.Repeat sequence analysis revealed 21 forward and 22 palindromic sequences in both Salvia cp genomes,and 17 and 21 tandem repeats in S.przewalskii and S.bulleyana,respectively.A synteny comparison of the Salvia spp.cp genomes showed a high degree of sequence similarity in the coding regions and a relatively high divergence of the intergenic spacers.Pairwise alignment and single-nucleotide polymorphism(SNP)analyses found some candidate fragments to identify Salvia spp.,such as the intergenic region of the trnV–ndhC,trnQ–rps16,atpI–atpH,psbA–ycf3,ycf1,rpoC2,ndhF,matK,rpoB,rpoA,and accD genes.All of the results—including the repeat sequences and SNP sites,the inverted repeat(IR)region border,and the phylogenetic analysis—showed that S.przewalskii and S.bulleyana are extremely similar from a genetic standpoint.The cp genome sequences of the two Salvia spp.reported here will pave the way for breeding,species identification,phylogenetic evolution,and cp genetic engineering studies of Salvia medicinal plants. 展开更多
关键词 SALVIA CHLOROPLAST GENOME COMPARATIVE ANALYSIS
下载PDF
De novo assembly of chloroplast genomes of Corchorus capsularis and C.olitorius yields species-specific InDel markers 被引量:6
19
作者 Shusheng Fang Liemei Zhang +1 位作者 Jianmin Qi Liwu Zhang 《The Crop Journal》 SCIE CSCD 2021年第1期216-226,共11页
Jute(Corchorus spp.)is a member of the Malvaceae family,which comprises more than 100 species.The systematic positions of jute species have remained unsettled.Chloroplasts are maternally inherited and their genomes ar... Jute(Corchorus spp.)is a member of the Malvaceae family,which comprises more than 100 species.The systematic positions of jute species have remained unsettled.Chloroplasts are maternally inherited and their genomes are widely used for plant phylogenetic studies.In the present study,the chloroplast genomes of Corchorus capsularis and C.olitorius were assembled,with sizes of respectively 161,088 and 161,766 bp.Both genomes contained 112 unique genes(78 protein-coding,four rRNA,and 30 tRNA genes).Four regionswith high variation between the two species were located in single-copy rather than inverted-repeat regions.A total of 66 simple sequence repeats(SSRs)were identified in the C.capsularis chloroplast genome and 56 in that of C.olitorius.Comparison of the two chloroplast genome sequences permitted the evaluation of nucleotide variation including 2417 single-nucleotide polymorphisms sites and 294 insertion or deletion sites,of which one marker(cpInDel 205)could discriminate the two jute species.Comparison of the C.capsularis and C.olitorius chloroplast genomeswith those of other species in theMalvaceae revealed breakpoints in the accD locus,which is involved in fatty acid synthesis,in C.capsularis and C.olitorius.This finding suggests that genes from the chloroplast genomemight have been transferred to the nuclear genome in some Corchorus species.This hypothesis was supported by synteny analysis of the accD region among the nuclear,chloroplast,and mitochondrial genomes.To our knowledge,this is the first report of the assembled chloroplast genome sequences of C.capsularis and C.olitorius.C.capsularis and C.olitorius are closely related to Gossypium species and there are abundant microstructure variations between these two genera.These results will expand our understanding of the systematics of species in the Malvaceae. 展开更多
关键词 JUTE Corchorus Genome CHLOROPLAST Insertion or deletion
下载PDF
Rapid and Accurate Sequencing of Enterovirus Genomes Using MinION Nanopore Sequencer 被引量:11
20
作者 WANG Ji KE Yue Hua +6 位作者 ZHANG Yong HUANG Ke Qiang WANG Lei SHEN Xin Xin DONG Xiao Ping XU Wen Bo MA Xue Jun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第10期718-726,共9页
Objective Knowledge of an enterovirus genome sequence is very important in epidemiological investigation to identify transmission patterns and ascertain the extent of an outbreak. The MinION sequencer is increasingly ... Objective Knowledge of an enterovirus genome sequence is very important in epidemiological investigation to identify transmission patterns and ascertain the extent of an outbreak. The MinION sequencer is increasingly used to sequence various viral pathogens in many clinical situations because of its long reads, portability, real-time accessibility of sequenced data, and very low initial costs. However, information is lacking on MinION sequencing of enterovirus genomes. Methods In this proof-of-concept study using Enterovirus 71 (EV71) and Coxsackievirus A16 (CA16) strains as examples, we established an amplicon-based whole genome sequencing method using MinION. We explored the accuracy, minimum sequencing time, discrimination and high-throughput sequencing ability of MinION, and compared its performance with Sanger sequencing. Results Within the first minute (min) of sequencing, the accuracy of MinION was 98.5% for the single EV71 strain and 94.12%-97.33% for 10 genetically-related CA16 strains. In as little as 14 min, 99% identity was reached for the single EV71 strain, and in 17 min (on average), 99% identity was achieved for 10 CA16 strains in a single run. Conclusion MinION is suitable for whole genome sequencing of enteroviruses with sufficient accuracy and fine discrimination and has the potential as a fast, reliable and convenient method for routine use. 展开更多
关键词 Nanopore sequencing MinION Enterovirus Single molecule sequencing Viral genome sequencing
下载PDF
上一页 1 2 117 下一页 到第
使用帮助 返回顶部