受生物基因片段重叠表达现象的启发，文中提出了一种新的基于重叠表达进化算法——MEOE（Multigene Evolutionary algorithm based on Overlapped Expression）．文章具体描述了MEOE的基因表达结构及相应的算法．不同于已有的工作，在M...受生物基因片段重叠表达现象的启发，文中提出了一种新的基于重叠表达进化算法——MEOE（Multigene Evolutionary algorithm based on Overlapped Expression）．文章具体描述了MEOE的基因表达结构及相应的算法．不同于已有的工作，在MEOE中作为遗传物质的基因具有重复表达的概率，同时算法融合了免疫算法关于浓度的计算技术．文章对MEOE算法作了较为全面的分析，讨论了算法在表达空间、可表达性、性状遗传上的特点，并与传统算法作了相应比较．详尽的实验证明，MEOE算法在速度上是GEP的2．5～9．4倍．在高次函数发现问题上MEOE算法的成功率比GEP提高至少一个数量级．另外，通过实验证明了基于密度的概率选择函数在高次函数发现问题上具有一定优势．展开更多
基因表达式程序设计是一种基于基因组和表现型组的新型遗传算法,该算法在运行时具有很高的运行效率,实验表明在求解很多问题时比遗传程序设计优越两个数量级以上。通过对基因表达式程序设计的变异算子进行分析,发现在个体变异过程中存...基因表达式程序设计是一种基于基因组和表现型组的新型遗传算法,该算法在运行时具有很高的运行效率,实验表明在求解很多问题时比遗传程序设计优越两个数量级以上。通过对基因表达式程序设计的变异算子进行分析,发现在个体变异过程中存在着大量的基因漂移现象,这些漂移的基因一方面造就了种群的多样性,但是另一方面也降低了算法的效率,阻碍了算法精度的提高。为此,构造了一种新的算子——漂移抑制算子,通过在基因表达式程序设计方法中加入此漂移抑制算子构造出一种新的算法—基因漂移抑制算法(Gene Drifting Suppression Algorithm Based on Gene Expression Programming,GDSA-GEP),该算法在保持种群多样性的同时,能有效地控制基因的过度漂移。实验结果表明,新算法能有效地提高问题的求解精度。展开更多
Crop domestication has fundamentally altered the course of human history,causing a shift from huntergatherer to agricultural societies and stimulating the rise of modern civilization.A greater understanding of crop do...Crop domestication has fundamentally altered the course of human history,causing a shift from huntergatherer to agricultural societies and stimulating the rise of modern civilization.A greater understanding of crop domestication would provide a theoretical basis for how we could improve current crops and develop new crops to deal with environmental challenges in a sustainable manner.Here,we provide a comprehensive summary of the similarities and differences in the domestication processes of maize and rice,two major staple food crops that feed the world.We propose that maize and rice might have evolved distinct genetic solutions toward domestication.Maize and rice domestication appears to be associated with distinct regulatory and evolutionary mechanisms.Rice domestication tended to select de novo,loss-of-function,coding variation,while maize domestication more frequently favored standing,gain-offunction,regulatory variation.At the gene network level,distinct genetic paths were used to acquire convergent phenotypes in maize and rice domestication,during which different central genes were utilized,orthologous genes played different evolutionary roles,and unique genes or regulatory modules were acquired for establishing new traits.Finally,we discuss how the knowledge gained from past domestication processes,together with emerging technologies,could be exploited to improve modern crop breeding and domesticate new crops to meet increasing human demands.展开更多
Members of the activity of bc1 complex (ABC1) family are protein kinases that are widely found in prokaryotes and eukaryotes. Previous studies showed that several plant ABC1 genes participated in the abiotic stress re...Members of the activity of bc1 complex (ABC1) family are protein kinases that are widely found in prokaryotes and eukaryotes. Previous studies showed that several plant ABC1 genes participated in the abiotic stress response. Here, we present the systematic identification of rice and Arabidopsis ABC1 genes and the expression analysis of rice ABC1 genes. A total of 15 and 17 ABC1 genes from the rice and Arabidopsis genomes, respectively, were identified using a bioinformatics approach. Phylogenetic analyses of these proteins suggested that the divergence of this family had occurred and their main characteristics were established before the monocot-dicot split. Indeed, species-specific expansion contributed to the evolution of this family in rice and Arabidopsis after the monocot-dicot split. Intron/exon structure analysis indicated that most of the orthologous genes had similar exon sizes, but diverse intron sizes, and the rice genes contained larger introns, moreover, intron gain was an important event accompanying the recent evolution of the rice ABC1 family. Multiple sequence alignment revealed one conserved amino acid segment and four conserved amino acids in the ABC1 domain. Online subcellular localization predicted that nine rice ABC1 proteins were localized in chloroplasts. Real-time RT-PCR established that the rice ABC1 genes were primarily expressed in leaves and the expression could be modulated by a broad range of abiotic factors such as H2O2, abscisic acid, low temperature, drought, darkness and high salinity. These results reveal that the rice ABC1 gene family plays roles in the environmental stress response and specific biological processes of rice.展开更多
Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology,regenerative biology,and toxicology.In the present study,we combine both ...Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology,regenerative biology,and toxicology.In the present study,we combine both morphological and molecular data to infer phylogenetic relationships at family-genus level and propose new evolutionary hypotheses for the class Heterotrichea.The main results include:(1)96 new ribosomal DNA sequences from 36 populations,representing eight families and 13 genera,including three poorly annotated genera,Folliculinopsis,Ampullofolliculina and Linostomella;(2)the earliest-branching families are Spirostomidae in single-gene trees and Peritromidae in the concatenated tree,but the family Peritromidae probably represents the basal lineage based on its possession of many"primitive"morphological characters;(3)some findings in molecular trees are not supported by morphological evidence,such as the family Blepharismidae is one of the most recent branches and the relationship between Fabreidae and Folliculinidae is very close;(4)the systematic positions of Condylostomatidae,Climacostomidae,and Gruberiidae remain uncertain based either on morphological or molecular data;and(5)the monophyly of each genus included in the present study is supported by the molecular phylogenetic trees,except for Blepharisma in the SSU r DNA tree and Folliculina in the ITS1-5.8 S-ITS2 tree.展开更多
In this study,our aim is to address the problem of gene selection by proposing a hybrid bio-inspired evolutionary algorithm that combines Grey Wolf Optimization(GWO)with Harris Hawks Optimization(HHO)for feature selec...In this study,our aim is to address the problem of gene selection by proposing a hybrid bio-inspired evolutionary algorithm that combines Grey Wolf Optimization(GWO)with Harris Hawks Optimization(HHO)for feature selection.Themotivation for utilizingGWOandHHOstems fromtheir bio-inspired nature and their demonstrated success in optimization problems.We aimto leverage the strengths of these algorithms to enhance the effectiveness of feature selection in microarray-based cancer classification.We selected leave-one-out cross-validation(LOOCV)to evaluate the performance of both two widely used classifiers,k-nearest neighbors(KNN)and support vector machine(SVM),on high-dimensional cancer microarray data.The proposed method is extensively tested on six publicly available cancer microarray datasets,and a comprehensive comparison with recently published methods is conducted.Our hybrid algorithm demonstrates its effectiveness in improving classification performance,Surpassing alternative approaches in terms of precision.The outcomes confirm the capability of our method to substantially improve both the precision and efficiency of cancer classification,thereby advancing the development ofmore efficient treatment strategies.The proposed hybridmethod offers a promising solution to the gene selection problem in microarray-based cancer classification.It improves the accuracy and efficiency of cancer diagnosis and treatment,and its superior performance compared to other methods highlights its potential applicability in realworld cancer classification tasks.By harnessing the complementary search mechanisms of GWO and HHO,we leverage their bio-inspired behavior to identify informative genes relevant to cancer diagnosis and treatment.展开更多
This article provides morphological descriptions and illustrations of microfungi associated with the invasive weed,Chro-molaena odorata,which were mainly collected in northern Thailand.Seventy-seven taxa distributed i...This article provides morphological descriptions and illustrations of microfungi associated with the invasive weed,Chro-molaena odorata,which were mainly collected in northern Thailand.Seventy-seven taxa distributed in ten orders,23 families(of which Neomassarinaceae is new),12 new genera(Chromolaenicola,Chromolaenomyces,Longiappendispora,Pseudocapulatispora,Murichromolaenicola,Neoophiobolus,Paraleptospora,Pseudoroussoella,Pseudostaurosphaeria,Pseudothyridariella,Setoarthopyrenia,Xenoroussoella),47 new species(Aplosporella chromolaenae,Arthrinium chromolae-nae,Chromolaenicola chiangraiensis,C.lampangensis,C.nanensis,C.thailandensis,Chromolaenomyces appendiculatus,Diaporthe chromolaenae,Didymella chromolaenae,Dyfrolomyces chromolaenae,Leptospora chromolaenae,L.phraeana,Longiappendispora chromolaenae,Memnoniella chromolaenae,Montagnula chiangraiensis,M.chromolaenae,M.chromo-laenicola,M.thailandica,Murichromolaenicola chiangraiensis,M.chromolaenae,Muyocopron chromolaenae,M.chromo-laenicola,Neomassarina chromolaenae,Neoophiobolus chromolaenae,Neopyrenochaeta chiangraiensis,N.chromolaenae,N.thailandica,N.triseptatispora,Nigrograna chromolaenae,Nothophoma chromolaenae,Paraleptospora chromolaenae,P.chromolaenicola,Patellaria chromolaenae,Pseudocapulatispora longiappendiculata,Pseudoroussoella chromolaenae,Pseudostaurosphaeria chromolaenae,P.chromolaenicola,Pseudothyridariella chromolaenae,Pyrenochaetopsis chromolae-nae,Rhytidhysteron chromolaenae,Setoarthopyrenia chromolaenae,Sphaeropsis chromolaenicola,Tremateia chiangraiensis,T.chromolaenae,T.thailandensis,Xenoroussoella triseptata,Yunnanensis chromolaenae),12 new host records,three new taxonomic combinations(Chromolaenicola siamensis,Pseudoroussoella elaeicola,Pseudothyridariella mahakashae),and two reference specimens(Torula chromolaenae,T.fici)are described and illustrated.Unlike some other hosts,e.g.bamboo(Poaceae)and Pandanaceae,the dominant group of fungi on Siam weed were Dothideomycetes.Only 15 species previously recorded from northern Thailand were found in t展开更多
The traditional knowledge in textbooks indicated that cephalochordates were the closest relatives to vertebrates among all extant organisms. However, this opinion was challenged by several recent phylogenetic studies ...The traditional knowledge in textbooks indicated that cephalochordates were the closest relatives to vertebrates among all extant organisms. However, this opinion was challenged by several recent phylogenetic studies using hundreds of nuclear genes. The researchers suggested that urochordates, but not cephalochordates, should be the closest living relatives to vertebrates. In the present study, by using data generated from hundreds of mtDNA sequences, we revalue the deuterostome phylogeny in terms of whole mitochondrial genomes （mitogenomes）. Our results firmly demonstrate that each of extant deuterostome phyla and chordate subphyla is monophyletic. But the results present several alternative phylogenetic trees depending on different sequence datasets used in the analysis. Although no clear phylogenetic relationships are obtained, those trees indicate that the ancient common ancestor diversified rapidly soon after their appearance in the early Cambrian and generated all major deuterostome lineages during a short historical period, which is consistent with ＂Cambrian explosion＂ revealed by paleontologists. It was the 520-million-year＇s evolution that obscured the phylogenetic relationships of extant deuterostomes. Thus, we conclude that an integrative analysis approach rather than simply using more DNA sequences should be employed to address the distant evolutionary relationship.展开更多
miR166作为重要的转录后调节因子,在植物的生长发育和对逆境胁迫的反应中扮演着重要的角色。利用PmiREN、Ensembl Plants数据库、MEGA-X、DNAMAN软件以及RNAfold web server、WebLogo和psRNA Target在线网站对小麦miR166(Tae-miR166)基...miR166作为重要的转录后调节因子,在植物的生长发育和对逆境胁迫的反应中扮演着重要的角色。利用PmiREN、Ensembl Plants数据库、MEGA-X、DNAMAN软件以及RNAfold web server、WebLogo和psRNA Target在线网站对小麦miR166(Tae-miR166)基因家族的进化特性和表达模式进行分析。在PmiREN数据库中搜索到19个Tae-miR166基因家族成员,染色体定位发现Tae-miR166成员定位于14条染色体上。序列比对发现Tae-miR166的成熟体序列高度保守。进化分析结果表明,Tae-miR166基因家族成员分别处于4个进化分支。靶基因预测结果表明,Tae-miR166的靶基因包括Ⅲ类同源异型结构域亮氨酸拉链蛋白、β半乳糖苷酶和钙依赖性蛋白激酶等。转录组数据分析表明Tae-miR166家族19个成员在小麦6个组织中都有表达,在籽粒和穗中表达量最高。荧光定量PCR结果表明,Tae-miR166家族15个成员在镉、干旱和低温胁迫处理后的表达模式存在差异,说明Tae-miR166基因家族在植株抵御非生物胁迫时发挥着重要作用。本研究为进一步阐明Tae-miR166基因家族的功能提供了理论依据。展开更多
文摘受生物基因片段重叠表达现象的启发，文中提出了一种新的基于重叠表达进化算法——MEOE（Multigene Evolutionary algorithm based on Overlapped Expression）．文章具体描述了MEOE的基因表达结构及相应的算法．不同于已有的工作，在MEOE中作为遗传物质的基因具有重复表达的概率，同时算法融合了免疫算法关于浓度的计算技术．文章对MEOE算法作了较为全面的分析，讨论了算法在表达空间、可表达性、性状遗传上的特点，并与传统算法作了相应比较．详尽的实验证明，MEOE算法在速度上是GEP的2．5～9．4倍．在高次函数发现问题上MEOE算法的成功率比GEP提高至少一个数量级．另外，通过实验证明了基于密度的概率选择函数在高次函数发现问题上具有一定优势．
文摘基因表达式程序设计是一种基于基因组和表现型组的新型遗传算法,该算法在运行时具有很高的运行效率,实验表明在求解很多问题时比遗传程序设计优越两个数量级以上。通过对基因表达式程序设计的变异算子进行分析,发现在个体变异过程中存在着大量的基因漂移现象,这些漂移的基因一方面造就了种群的多样性,但是另一方面也降低了算法的效率,阻碍了算法精度的提高。为此,构造了一种新的算子——漂移抑制算子,通过在基因表达式程序设计方法中加入此漂移抑制算子构造出一种新的算法—基因漂移抑制算法(Gene Drifting Suppression Algorithm Based on Gene Expression Programming,GDSA-GEP),该算法在保持种群多样性的同时,能有效地控制基因的过度漂移。实验结果表明,新算法能有效地提高问题的求解精度。
基金This work was supported by the National Natural Science Foundation of China(32025027 and 31971892)the National Key Research and Exploiting Maize and Rice Domestication Development Program of China(2016YFD0100303)the Recruitment Program of Global Experts,and the Fundamental Research Funds for the Central Universities to F.T.Q.C.was supported by US NSF grant IOS 1934865 to John Doebley.
文摘Crop domestication has fundamentally altered the course of human history,causing a shift from huntergatherer to agricultural societies and stimulating the rise of modern civilization.A greater understanding of crop domestication would provide a theoretical basis for how we could improve current crops and develop new crops to deal with environmental challenges in a sustainable manner.Here,we provide a comprehensive summary of the similarities and differences in the domestication processes of maize and rice,two major staple food crops that feed the world.We propose that maize and rice might have evolved distinct genetic solutions toward domestication.Maize and rice domestication appears to be associated with distinct regulatory and evolutionary mechanisms.Rice domestication tended to select de novo,loss-of-function,coding variation,while maize domestication more frequently favored standing,gain-offunction,regulatory variation.At the gene network level,distinct genetic paths were used to acquire convergent phenotypes in maize and rice domestication,during which different central genes were utilized,orthologous genes played different evolutionary roles,and unique genes or regulatory modules were acquired for establishing new traits.Finally,we discuss how the knowledge gained from past domestication processes,together with emerging technologies,could be exploited to improve modern crop breeding and domesticate new crops to meet increasing human demands.
基金supported by grants from the National Program on the Development of Basic Research of China (Grant No. 2006CB101700)the National Natural Science Foundation of China (Grant No. 30971846)the Vital Project of Natural Science in Universities of Jiangsu Province, China (Grant No. 09KJA210002)
文摘Members of the activity of bc1 complex (ABC1) family are protein kinases that are widely found in prokaryotes and eukaryotes. Previous studies showed that several plant ABC1 genes participated in the abiotic stress response. Here, we present the systematic identification of rice and Arabidopsis ABC1 genes and the expression analysis of rice ABC1 genes. A total of 15 and 17 ABC1 genes from the rice and Arabidopsis genomes, respectively, were identified using a bioinformatics approach. Phylogenetic analyses of these proteins suggested that the divergence of this family had occurred and their main characteristics were established before the monocot-dicot split. Indeed, species-specific expansion contributed to the evolution of this family in rice and Arabidopsis after the monocot-dicot split. Intron/exon structure analysis indicated that most of the orthologous genes had similar exon sizes, but diverse intron sizes, and the rice genes contained larger introns, moreover, intron gain was an important event accompanying the recent evolution of the rice ABC1 family. Multiple sequence alignment revealed one conserved amino acid segment and four conserved amino acids in the ABC1 domain. Online subcellular localization predicted that nine rice ABC1 proteins were localized in chloroplasts. Real-time RT-PCR established that the rice ABC1 genes were primarily expressed in leaves and the expression could be modulated by a broad range of abiotic factors such as H2O2, abscisic acid, low temperature, drought, darkness and high salinity. These results reveal that the rice ABC1 gene family plays roles in the environmental stress response and specific biological processes of rice.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(2018SDKJ0406-1)the National Natural Science Foundation of China(3203000059,31970398)。
文摘Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology,regenerative biology,and toxicology.In the present study,we combine both morphological and molecular data to infer phylogenetic relationships at family-genus level and propose new evolutionary hypotheses for the class Heterotrichea.The main results include:(1)96 new ribosomal DNA sequences from 36 populations,representing eight families and 13 genera,including three poorly annotated genera,Folliculinopsis,Ampullofolliculina and Linostomella;(2)the earliest-branching families are Spirostomidae in single-gene trees and Peritromidae in the concatenated tree,but the family Peritromidae probably represents the basal lineage based on its possession of many"primitive"morphological characters;(3)some findings in molecular trees are not supported by morphological evidence,such as the family Blepharismidae is one of the most recent branches and the relationship between Fabreidae and Folliculinidae is very close;(4)the systematic positions of Condylostomatidae,Climacostomidae,and Gruberiidae remain uncertain based either on morphological or molecular data;and(5)the monophyly of each genus included in the present study is supported by the molecular phylogenetic trees,except for Blepharisma in the SSU r DNA tree and Folliculina in the ITS1-5.8 S-ITS2 tree.
基金the Deputyship for Research and Innovation,“Ministry of Education”in Saudi Arabia for funding this research(IFKSUOR3-014-3).
文摘In this study,our aim is to address the problem of gene selection by proposing a hybrid bio-inspired evolutionary algorithm that combines Grey Wolf Optimization(GWO)with Harris Hawks Optimization(HHO)for feature selection.Themotivation for utilizingGWOandHHOstems fromtheir bio-inspired nature and their demonstrated success in optimization problems.We aimto leverage the strengths of these algorithms to enhance the effectiveness of feature selection in microarray-based cancer classification.We selected leave-one-out cross-validation(LOOCV)to evaluate the performance of both two widely used classifiers,k-nearest neighbors(KNN)and support vector machine(SVM),on high-dimensional cancer microarray data.The proposed method is extensively tested on six publicly available cancer microarray datasets,and a comprehensive comparison with recently published methods is conducted.Our hybrid algorithm demonstrates its effectiveness in improving classification performance,Surpassing alternative approaches in terms of precision.The outcomes confirm the capability of our method to substantially improve both the precision and efficiency of cancer classification,thereby advancing the development ofmore efficient treatment strategies.The proposed hybridmethod offers a promising solution to the gene selection problem in microarray-based cancer classification.It improves the accuracy and efficiency of cancer diagnosis and treatment,and its superior performance compared to other methods highlights its potential applicability in realworld cancer classification tasks.By harnessing the complementary search mechanisms of GWO and HHO,we leverage their bio-inspired behavior to identify informative genes relevant to cancer diagnosis and treatment.
基金Ausana Mapook was financially supported by Research and Researchers for Industry Program(RRI)PHD57I0012,Thailand and the German Academic Exchange Service(DAAD)for a joint TRF-DAAD(PPP 2017–2018)academic exchange grant to Kevin D.Hyde and Marc Stadler.Kevin D.Hyde thanks to the 2019 high-end foreign expert introduction plan to Kunming Institute of Botany(granted by the Ministry of Science and Technology of the People’s Republic of China,Grant Number G20190139006)Thailand Research grants entitled Biodiversity,phylogeny and role of fungal endophytes on above parts of Rhizophora apiculata and Nypa fruticans(Grant No:RSA5980068)+1 种基金the future of specialist fungi in a changing climate:baseline data for generalist and specialist fungi associated with ants,Rhododendron species and Dracaena species(Grant No:DBG6080013)Impact of climate change on fungal diversity and biogeography in the Greater Mekong Subregion(Grant No:RDG6130001).
文摘This article provides morphological descriptions and illustrations of microfungi associated with the invasive weed,Chro-molaena odorata,which were mainly collected in northern Thailand.Seventy-seven taxa distributed in ten orders,23 families(of which Neomassarinaceae is new),12 new genera(Chromolaenicola,Chromolaenomyces,Longiappendispora,Pseudocapulatispora,Murichromolaenicola,Neoophiobolus,Paraleptospora,Pseudoroussoella,Pseudostaurosphaeria,Pseudothyridariella,Setoarthopyrenia,Xenoroussoella),47 new species(Aplosporella chromolaenae,Arthrinium chromolae-nae,Chromolaenicola chiangraiensis,C.lampangensis,C.nanensis,C.thailandensis,Chromolaenomyces appendiculatus,Diaporthe chromolaenae,Didymella chromolaenae,Dyfrolomyces chromolaenae,Leptospora chromolaenae,L.phraeana,Longiappendispora chromolaenae,Memnoniella chromolaenae,Montagnula chiangraiensis,M.chromolaenae,M.chromo-laenicola,M.thailandica,Murichromolaenicola chiangraiensis,M.chromolaenae,Muyocopron chromolaenae,M.chromo-laenicola,Neomassarina chromolaenae,Neoophiobolus chromolaenae,Neopyrenochaeta chiangraiensis,N.chromolaenae,N.thailandica,N.triseptatispora,Nigrograna chromolaenae,Nothophoma chromolaenae,Paraleptospora chromolaenae,P.chromolaenicola,Patellaria chromolaenae,Pseudocapulatispora longiappendiculata,Pseudoroussoella chromolaenae,Pseudostaurosphaeria chromolaenae,P.chromolaenicola,Pseudothyridariella chromolaenae,Pyrenochaetopsis chromolae-nae,Rhytidhysteron chromolaenae,Setoarthopyrenia chromolaenae,Sphaeropsis chromolaenicola,Tremateia chiangraiensis,T.chromolaenae,T.thailandensis,Xenoroussoella triseptata,Yunnanensis chromolaenae),12 new host records,three new taxonomic combinations(Chromolaenicola siamensis,Pseudoroussoella elaeicola,Pseudothyridariella mahakashae),and two reference specimens(Torula chromolaenae,T.fici)are described and illustrated.Unlike some other hosts,e.g.bamboo(Poaceae)and Pandanaceae,the dominant group of fungi on Siam weed were Dothideomycetes.Only 15 species previously recorded from northern Thailand were found in t
基金supported by the National Natural Sci-ence Foundation of China (No. 30570208 and 30830023)the Specialized Research Fund for the Doctoral Pro-gram of Higher Education from the Ministry of Education, China (No. 20070384041).
文摘The traditional knowledge in textbooks indicated that cephalochordates were the closest relatives to vertebrates among all extant organisms. However, this opinion was challenged by several recent phylogenetic studies using hundreds of nuclear genes. The researchers suggested that urochordates, but not cephalochordates, should be the closest living relatives to vertebrates. In the present study, by using data generated from hundreds of mtDNA sequences, we revalue the deuterostome phylogeny in terms of whole mitochondrial genomes （mitogenomes）. Our results firmly demonstrate that each of extant deuterostome phyla and chordate subphyla is monophyletic. But the results present several alternative phylogenetic trees depending on different sequence datasets used in the analysis. Although no clear phylogenetic relationships are obtained, those trees indicate that the ancient common ancestor diversified rapidly soon after their appearance in the early Cambrian and generated all major deuterostome lineages during a short historical period, which is consistent with ＂Cambrian explosion＂ revealed by paleontologists. It was the 520-million-year＇s evolution that obscured the phylogenetic relationships of extant deuterostomes. Thus, we conclude that an integrative analysis approach rather than simply using more DNA sequences should be employed to address the distant evolutionary relationship.
文摘miR166作为重要的转录后调节因子,在植物的生长发育和对逆境胁迫的反应中扮演着重要的角色。利用PmiREN、Ensembl Plants数据库、MEGA-X、DNAMAN软件以及RNAfold web server、WebLogo和psRNA Target在线网站对小麦miR166(Tae-miR166)基因家族的进化特性和表达模式进行分析。在PmiREN数据库中搜索到19个Tae-miR166基因家族成员,染色体定位发现Tae-miR166成员定位于14条染色体上。序列比对发现Tae-miR166的成熟体序列高度保守。进化分析结果表明,Tae-miR166基因家族成员分别处于4个进化分支。靶基因预测结果表明,Tae-miR166的靶基因包括Ⅲ类同源异型结构域亮氨酸拉链蛋白、β半乳糖苷酶和钙依赖性蛋白激酶等。转录组数据分析表明Tae-miR166家族19个成员在小麦6个组织中都有表达,在籽粒和穗中表达量最高。荧光定量PCR结果表明,Tae-miR166家族15个成员在镉、干旱和低温胁迫处理后的表达模式存在差异,说明Tae-miR166基因家族在植株抵御非生物胁迫时发挥着重要作用。本研究为进一步阐明Tae-miR166基因家族的功能提供了理论依据。
