With the development and decreasing cost of sequencing techniques, it is possible for scientists to conduct deeper research in phylogenomics. During the procedure of phylogenomic analysis, the mostimportant and vitale...With the development and decreasing cost of sequencing techniques, it is possible for scientists to conduct deeper research in phylogenomics. During the procedure of phylogenomic analysis, the mostimportant and vitalest step is orthology prediction, for that the prerequisite to phylogenetic reconstruction is that the genes being compared are orthologous. Here we briefly review the related concept of orthology anddifferent methods for orthology prediction. We also provide recommendations to give some advice for better selection of orthology prediction methods.展开更多
Dear Editor,In dynamic environments,the memory system of the brain must be able to perceive and process conflicting experiences to reach an adaptive decision.In Drosophila,in contrast to consistent experiences,conflic...Dear Editor,In dynamic environments,the memory system of the brain must be able to perceive and process conflicting experiences to reach an adaptive decision.In Drosophila,in contrast to consistent experiences,conflicting experiences trigger significantly increased Rac1 activity which mediates active forgetting [1].The ability to cope with conflicting experiences but not simple learning experiences is impaired in mutants of multiple autism-risk genes [2].展开更多
Essential proteins are those necessary for the survival or reproduction of species and discovering such essential proteins is fundamental for understanding the minimal requirements for cellular life, which is also mea...Essential proteins are those necessary for the survival or reproduction of species and discovering such essential proteins is fundamental for understanding the minimal requirements for cellular life, which is also meaningful to the disease study and drug design. With the development of high-throughput techniques, a large number of Protein-Protein Interactions（PPIs） can be used to identify essential proteins at the network level. Up to now, though a series of network-based computational methods have been proposed, it is still a challenge to improve the prediction precision as the high false positives in PPI networks. In this paper, we propose a new method GOS to identify essential proteins by integrating the Gene expressions, Orthology, and Subcellular localization information.The gene expressions and subcellular localization information are used to determine whether a neighbor in the PPI network is reliable. Only reliable neighbors are considered when we analyze the topological characteristics of a protein in a PPI network. We also analyze the orthologous attributes of each protein to reflect its conservative features, and use a random walk model to integrate a protein＇s topological characteristics and its orthology. The experimental results on the yeast PPI network show that the proposed method GOS outperforms the ten existing methods DC, BC, CC, SC, EC, IC, NC, Pe C, ION, and CSC.展开更多
Wheat(Triticum aestivum L.)is a staple food crop consumed by more than 30%of world population.Nitrogen(N)fertilizer has been applied broadly in agriculture practice to improve wheat yield to meet the growing demands f...Wheat(Triticum aestivum L.)is a staple food crop consumed by more than 30%of world population.Nitrogen(N)fertilizer has been applied broadly in agriculture practice to improve wheat yield to meet the growing demands for food production.However,undue N fertilizer application and the low N use efficiency(NUE)of modern wheat varieties are aggravating environmental pollution and ecological deterioration.Under nitrogen-limiting conditions,the rice(Oryza sativa)abnormal cytokinin response1 repressor1(are1)mutant exhibits increased NUE,delayed senescence and consequently,increased grain yield.However,the function of ARE1 ortholog in wheat remains unknown.Here,we isolated and characterized three TaARE1 homoeologs from the elite Chinese winter wheat cultivar ZhengMai 7698.We then used CRISPR/Cas9-mediated targeted mutagenesis to generate a series of transgene-free mutant lines either with partial or triple-null taare1 alleles.All transgene-free mutant lines showed enhanced tolerance to N starvation,and showed delayed senescence and increased grain yield in field conditions.In particular,the AABBdd and aabbDD mutant lines exhibited delayed senescence and significantly increased grain yield without growth defects compared to the wild-type control.Together,our results underscore the potential to manipulate ARE1 orthologs through gene editing for breeding of high-yield wheat as well as other cereal crops with improved NUE.展开更多
Genome-scale assignment of orthologous genes is a fundamental and challenging problem in computational biology and has a wide range of applications in comparative genomics, functional genomics, and systems biology. Ma...Genome-scale assignment of orthologous genes is a fundamental and challenging problem in computational biology and has a wide range of applications in comparative genomics, functional genomics, and systems biology. Many methods based on sequence similarity, phylogenetic analysis, chromosomal syntenic information, and genome rearrangement have been proposed in recent years for ortholog assignment. Although these methods produce results that largely agree with each other, their results may still contain significant differences. In this article, we consider the recently proposed parsimony approach for assigning orthologs between closely related genomes based on genome rearrangement, which essentially attempts to transform one genome into another by the smallest number of genome rearrangement events including reversal, translocation, fusion, and fission, as well as gene duplication events. We will highlight some of the challenging algorithmic problems that arise in the approach including （i） minimum common substring partition, （ii） signed reversal distance with duplicates, and （iii） signed transposition distance with duplicates. The most recent progress towards the solution of these problems will be reviewed and some open questions will he posed. We will also discuss some possible extensions of the approach to the simultaneous comparison of multiple genomes.展开更多
Human and mouse orthologs are expected to have similar biological functions; however, many discrepancies have also been reported. We systematically compared human and mouse orthologs in terms of alternative splicing p...Human and mouse orthologs are expected to have similar biological functions; however, many discrepancies have also been reported. We systematically compared human and mouse orthologs in terms of alternative splicing patterns and expression profiles. Human-mouse orthologs are divergent in alternative splicing, as human orthologs could generally encode more isoforms than their mouse orthologs. In early embryos, exon skipping is far more common with human orthologs, whereas constitutive exons are more prevalent with mouse orthologs. This may correlate with divergence in expression of splicing regulators. Orthologous expression similarities are different in distinct embryonic stages, with the highest in morula. Expression differences for orthologous transcription factor genes could play an important role in orthologous expression discordance. We further detected largely orthologous divergence in differential expression between distinct embryonic stages. Collectively, our study uncovers significant orthologous divergence from multiple aspects, which may result in functional differences and dynamics between human-mouse orthologs during embryonic development.展开更多
Although Drosophila simulans is closely related to D. melanogaster, very few cytochrome P450 genes have been studied in this species until now. As Cyp6a2 from D. melanogaster is a major gene implicated in the detoxifi...Although Drosophila simulans is closely related to D. melanogaster, very few cytochrome P450 genes have been studied in this species until now. As Cyp6a2 from D. melanogaster is a major gene implicated in the detoxification of xenobiotic molecules, we decided to look for its ortholog in D. simulans. The isolated gene, Cyp6a26, presents structural characteristics very similar to those of Cyp6a2： an identical size of 1590-bp comprising two exons separated by a 69-bp intron and a nucleotide sequence homology of 95%. Many putative transcriptionally important motifs were identified in the upstream DNAs of the two genes but only 16 elements are in common positions. Treatment of flies with phenobarbital leads to an increased production of Cyp6a26 mRNAs. The expression of Cyp6a26 mRNAs varies following developmental stages in the same manner as Cyp6a2. Immunohistochemistry experiments of phenobarbital-treated adult drosophila show that the spatial expression pattern of the two proteins is also conserved between the two species. All these data argue in favor of the conservation of the function of these homologous genes between the two Drosophila species.展开更多
The genus Salix is a common component of the Northern Hemisphere dendroflora with important ecological and economic value.However,taxonomy and systematics of Salix is extremely difficult and relationships between main...The genus Salix is a common component of the Northern Hemisphere dendroflora with important ecological and economic value.However,taxonomy and systematics of Salix is extremely difficult and relationships between main lineages,especially deep phylogenies,remain largely unresolved.In this study,we used genome-skimming,plastome assembly,and single-copy orthologs(SCOs)from 66 Salix accessions,along with publicly available plastome and sequence read archive(SRA)datasets to obtain a robust backbone phylogeny of Salix,clarify relationships between its main lineages,and gain a more precise understanding of the origin and diversification of this species-rich genus.The plastome and SCO datasets resolved Salix into two robust clades,with plastome-based phylogenies lacking inner resolution and SCO offering fully resolved phylogenies.Our results support the classification of Salix into five subgenera:Salix,Urbaniana,Triandrae,Longifoliae and Vetrix.We observed a significant acceleration in the diversification rate within the Chamaetia-Vetrix clade,while Salix exhibited increased rates of diversification spanning from the early Oligocene to the late Miocene.These changes coincided with contemporaneous tectonic and climate change events.Our results provide a foundation for future systematic and evolutionary studies of Salix.Additionally,we showed that genome skimming data is an efficient,rapid,and reliable approach for obtaining extensive genomic data for phylogenomic studies,enabling the comprehensive elucidation of Salix relationships.展开更多
基金supported by the National Natural Science Foundation of China (J0930005,30970350,31071959)
文摘With the development and decreasing cost of sequencing techniques, it is possible for scientists to conduct deeper research in phylogenomics. During the procedure of phylogenomic analysis, the mostimportant and vitalest step is orthology prediction, for that the prerequisite to phylogenetic reconstruction is that the genes being compared are orthologous. Here we briefly review the related concept of orthology anddifferent methods for orthology prediction. We also provide recommendations to give some advice for better selection of orthology prediction methods.
基金supported by grants from the National Natural Science Foundation of China (31970955 and 31700912)。
文摘Dear Editor,In dynamic environments,the memory system of the brain must be able to perceive and process conflicting experiences to reach an adaptive decision.In Drosophila,in contrast to consistent experiences,conflicting experiences trigger significantly increased Rac1 activity which mediates active forgetting [1].The ability to cope with conflicting experiences but not simple learning experiences is impaired in mutants of multiple autism-risk genes [2].
基金supported by the National Natural Science Foundation for Excellent Young Scholars(No.61622213)the National Natural Science Foundation of China(Nos.61232001,61370024,and 61428209)
文摘Essential proteins are those necessary for the survival or reproduction of species and discovering such essential proteins is fundamental for understanding the minimal requirements for cellular life, which is also meaningful to the disease study and drug design. With the development of high-throughput techniques, a large number of Protein-Protein Interactions（PPIs） can be used to identify essential proteins at the network level. Up to now, though a series of network-based computational methods have been proposed, it is still a challenge to improve the prediction precision as the high false positives in PPI networks. In this paper, we propose a new method GOS to identify essential proteins by integrating the Gene expressions, Orthology, and Subcellular localization information.The gene expressions and subcellular localization information are used to determine whether a neighbor in the PPI network is reliable. Only reliable neighbors are considered when we analyze the topological characteristics of a protein in a PPI network. We also analyze the orthologous attributes of each protein to reflect its conservative features, and use a random walk model to integrate a protein＇s topological characteristics and its orthology. The experimental results on the yeast PPI network show that the proposed method GOS outperforms the ten existing methods DC, BC, CC, SC, EC, IC, NC, Pe C, ION, and CSC.
基金funded by National Key Research and Development Program of China(2020YFE0202300)the Agricultural Science and Technology Innovation Program(CAAS-ZDRW202109)+1 种基金Fundamental Research Funds for Central Non-Profit of Institute of Crop Sciences,Chinese Academy of Agricultural Sciences(S2021ZD03)National Engineering Laboratory of Crop Molecular Breeding。
文摘Wheat(Triticum aestivum L.)is a staple food crop consumed by more than 30%of world population.Nitrogen(N)fertilizer has been applied broadly in agriculture practice to improve wheat yield to meet the growing demands for food production.However,undue N fertilizer application and the low N use efficiency(NUE)of modern wheat varieties are aggravating environmental pollution and ecological deterioration.Under nitrogen-limiting conditions,the rice(Oryza sativa)abnormal cytokinin response1 repressor1(are1)mutant exhibits increased NUE,delayed senescence and consequently,increased grain yield.However,the function of ARE1 ortholog in wheat remains unknown.Here,we isolated and characterized three TaARE1 homoeologs from the elite Chinese winter wheat cultivar ZhengMai 7698.We then used CRISPR/Cas9-mediated targeted mutagenesis to generate a series of transgene-free mutant lines either with partial or triple-null taare1 alleles.All transgene-free mutant lines showed enhanced tolerance to N starvation,and showed delayed senescence and increased grain yield in field conditions.In particular,the AABBdd and aabbDD mutant lines exhibited delayed senescence and significantly increased grain yield without growth defects compared to the wild-type control.Together,our results underscore the potential to manipulate ARE1 orthologs through gene editing for breeding of high-yield wheat as well as other cereal crops with improved NUE.
基金supported by the NSF of USA under Grant No. IIS-0711129
文摘Genome-scale assignment of orthologous genes is a fundamental and challenging problem in computational biology and has a wide range of applications in comparative genomics, functional genomics, and systems biology. Many methods based on sequence similarity, phylogenetic analysis, chromosomal syntenic information, and genome rearrangement have been proposed in recent years for ortholog assignment. Although these methods produce results that largely agree with each other, their results may still contain significant differences. In this article, we consider the recently proposed parsimony approach for assigning orthologs between closely related genomes based on genome rearrangement, which essentially attempts to transform one genome into another by the smallest number of genome rearrangement events including reversal, translocation, fusion, and fission, as well as gene duplication events. We will highlight some of the challenging algorithmic problems that arise in the approach including （i） minimum common substring partition, （ii） signed reversal distance with duplicates, and （iii） signed transposition distance with duplicates. The most recent progress towards the solution of these problems will be reviewed and some open questions will he posed. We will also discuss some possible extensions of the approach to the simultaneous comparison of multiple genomes.
基金supported by the China Human Proteomics Project (2014DFB30010)the National High Technology Research and Development Program of China (2015AA020104)+1 种基金the National Natural Science Foundation of China (31071162)the Graduate School of East China Normal University
文摘Human and mouse orthologs are expected to have similar biological functions; however, many discrepancies have also been reported. We systematically compared human and mouse orthologs in terms of alternative splicing patterns and expression profiles. Human-mouse orthologs are divergent in alternative splicing, as human orthologs could generally encode more isoforms than their mouse orthologs. In early embryos, exon skipping is far more common with human orthologs, whereas constitutive exons are more prevalent with mouse orthologs. This may correlate with divergence in expression of splicing regulators. Orthologous expression similarities are different in distinct embryonic stages, with the highest in morula. Expression differences for orthologous transcription factor genes could play an important role in orthologous expression discordance. We further detected largely orthologous divergence in differential expression between distinct embryonic stages. Collectively, our study uncovers significant orthologous divergence from multiple aspects, which may result in functional differences and dynamics between human-mouse orthologs during embryonic development.
文摘Although Drosophila simulans is closely related to D. melanogaster, very few cytochrome P450 genes have been studied in this species until now. As Cyp6a2 from D. melanogaster is a major gene implicated in the detoxification of xenobiotic molecules, we decided to look for its ortholog in D. simulans. The isolated gene, Cyp6a26, presents structural characteristics very similar to those of Cyp6a2： an identical size of 1590-bp comprising two exons separated by a 69-bp intron and a nucleotide sequence homology of 95%. Many putative transcriptionally important motifs were identified in the upstream DNAs of the two genes but only 16 elements are in common positions. Treatment of flies with phenobarbital leads to an increased production of Cyp6a26 mRNAs. The expression of Cyp6a26 mRNAs varies following developmental stages in the same manner as Cyp6a2. Immunohistochemistry experiments of phenobarbital-treated adult drosophila show that the spatial expression pattern of the two proteins is also conserved between the two species. All these data argue in favor of the conservation of the function of these homologous genes between the two Drosophila species.
基金supported by NSFC(32070226,32360065)the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U23A20149)+3 种基金the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2024QZKK0200)Yunnan Fundamental Research Projects(202101AS070032)the CAS“Light ofWest China”Program(xbzg-zdsys-202110)the Yunnan Innovation Team Project(202305AS350004,with LD/NY/SB/CJG/CJH as the core member).
文摘The genus Salix is a common component of the Northern Hemisphere dendroflora with important ecological and economic value.However,taxonomy and systematics of Salix is extremely difficult and relationships between main lineages,especially deep phylogenies,remain largely unresolved.In this study,we used genome-skimming,plastome assembly,and single-copy orthologs(SCOs)from 66 Salix accessions,along with publicly available plastome and sequence read archive(SRA)datasets to obtain a robust backbone phylogeny of Salix,clarify relationships between its main lineages,and gain a more precise understanding of the origin and diversification of this species-rich genus.The plastome and SCO datasets resolved Salix into two robust clades,with plastome-based phylogenies lacking inner resolution and SCO offering fully resolved phylogenies.Our results support the classification of Salix into five subgenera:Salix,Urbaniana,Triandrae,Longifoliae and Vetrix.We observed a significant acceleration in the diversification rate within the Chamaetia-Vetrix clade,while Salix exhibited increased rates of diversification spanning from the early Oligocene to the late Miocene.These changes coincided with contemporaneous tectonic and climate change events.Our results provide a foundation for future systematic and evolutionary studies of Salix.Additionally,we showed that genome skimming data is an efficient,rapid,and reliable approach for obtaining extensive genomic data for phylogenomic studies,enabling the comprehensive elucidation of Salix relationships.
