Since the first MADS-box transcription factor genes were implicated in the establishment of floral organ identity in a couple of model plants, the size and scope of this gene family has begun to be appreciated in a mu...Since the first MADS-box transcription factor genes were implicated in the establishment of floral organ identity in a couple of model plants, the size and scope of this gene family has begun to be appreciated in a much wider range of species. Over the course of millions of years the number of MADS-box genes in plants has increased to the point that the Arabidopsis genome contains more than 100. The understanding gained from studying the evolution, regulation and function of multiple MADS-box genes in an increasing set of species, makes this large plant transcription factor gene family an ideal subject to study the processes that lead to an increase in gene number and the selective birth, death and repurposing of its component members. Here we will use examples taken from the MADS-box gene family to review what is known about the factors that influence the loss and retention of genes duplicated in different ways and examine the varied fates of the retained genes and their associated biological outcomes.展开更多
Autism spectrum disorder（ASD） encompasses a complex set of developmental neurological disorders,characterized by de？cits in social communication and excessive repetitive behaviors. In recent years, ASD is increasin...Autism spectrum disorder（ASD） encompasses a complex set of developmental neurological disorders,characterized by de？cits in social communication and excessive repetitive behaviors. In recent years, ASD is increasingly being considered as a disease of the synapse.One main type of genetic aberration leading to ASD is gene duplication, and several mouse models have been generated mimicking these mutations. Here, we studied the effects of MECP2 duplication and human chromosome15q11-13 duplication on synaptic development and neural circuit wiring in the mouse sensory cortices. We showed that mice carrying MECP2 duplication had speci？c defects in spine pruning, while the 15q11-13 duplication mouse model had impaired spine formation. Our results demonstrate that spine pathology varies signi？cantly between autism models and that distinct aspects of neural circuit development may be targeted in different ASD mutations.Our results further underscore the importance of gene dosage in normal development and function of the brain.展开更多
The worldwide declines in amphibian populations have largely been caused by infectious fungi and bacteria. Given that vertebrate immunity against these extracellular pathogens is primarily functioned by the major hist...The worldwide declines in amphibian populations have largely been caused by infectious fungi and bacteria. Given that vertebrate immunity against these extracellular pathogens is primarily functioned by the major histocompatibility complex（MHC） class Ⅱ molecules, the characterization and the evolution of amphibian MHC class Ⅱ genes have attracted increasing attention. The polymorphism of MHC class Ⅱ genes was found to be correlated with susceptibility to fungal pathogens in many amphibian species, suggesting the importance of studies on MHC class Ⅱ genes for amphibians. However, such studies on MHC class Ⅱ gene evolution have rarely been conducted on amphibians in China. In this study, we chose Omei treefrog（Rhacophorus omeimontis）, which lived moist environments easy for breeding bacteria, to study the polymorphism of its MHC class Ⅱ genes and the underlying evolutionary mechanisms. We amplified the entire MHC class ⅡB exon 2 sequence in the R. omeimontis using newly designed primers. We detected 102 putative alleles in 146 individuals. The number of alleles per individual ranged from one to seven, indicating that there are at least four loci containing MHC class ⅡB genes in R. omeimontis. The allelic polymorphism estimated from the 102 alleles in R. omeimontis was not high compared to that estimated in other anuran species. No significant gene recombination was detected in the 102 MHC class ⅡB exon 2 sequences. In contrast, both gene duplication and balancing selection greatly contributed to the variability in MHC class ⅡB exon 2 sequences of R. omeimontis. This study lays the groundwork for the future researches to comprehensively analyze the evolution of amphibian MHC genes and to assess the role of MHC gene polymorphisms in resistance against extracellular pathogens for amphibians in China.展开更多
Budding yeast (Saccharomyces cerevisiae) is a single cell model organism that is amenable to genome wide experimental interrogation using high-throughput genomics, proteomics
Artemisia argyi Le´vl.et Vant.,a perennial Artemisia herb with an intense fragrance,is widely used in traditional medicine in China and many other Asian countries.Here,we present a chromosome-scale genome assembl...Artemisia argyi Le´vl.et Vant.,a perennial Artemisia herb with an intense fragrance,is widely used in traditional medicine in China and many other Asian countries.Here,we present a chromosome-scale genome assembly of A.argyi comprising 3.89 Gb assembled into 17 pseudochromosomes.Phylogenetic and comparative genomic analyses revealed that A.argyi underwent a recent lineage-specificwhole-genomeduplication(WGD)event after divergence fromArtemisia annua,resulting in two subgenomes.Wedeciphered the diploid ancestral genome of A.argyi,and unbiased subgenome evolution was observed.The recent WGD led to a large number of duplicated genes in the A.argyi genome.Expansion of the terpene synthase(TPS)gene family through various types of gene duplication may have greatly contributed to the diversity of volatile terpenoids in A.argyi.In particular,we identified a typical germacrene D synthase gene cluster within the expanded TPS gene family.The entire biosynthetic pathways of germacrenes,(+)-borneol,and(+)-camphor were elucidated in A.argyi.In addition,partial deletion of the amorpha-4,11-diene synthase(ADS)gene and loss of function of ADS homologs may have resulted in the lack of artemisinin production in A.argyi.Our study provides newinsights into the genome evolution of Artemisia and lays a foundation for further improvement of the quality of this important medicinal plant.展开更多
Loss of the awn in some cereals including sorghum is a key transition during cereal domestication or improvement that has facilitated grain harvest and storage.The genetic basis for the loss of awn in sorghum during d...Loss of the awn in some cereals including sorghum is a key transition during cereal domestication or improvement that has facilitated grain harvest and storage.The genetic basis for the loss of awn in sorghum during domestication or improvement remains unknown.Here,we identified a transcription factor gene awn1 encoding an ALOG domain,which is responsible for awn loss during sorghum domestication or improvement.awn1 arose from a gene duplication from chromosome 10 that translocated to chromosome 3,recruiting a new promoter from the neighbouring intergenic region filled with"noncoding DNA",and recreating the first exon and intron.The awn1 acquires high expr`ession after duplication and represses the elongation of awns in domesticated sorghum.Comparative mapping revealed a high collinearity at awn1 paralog locus on chromosome 10 across cereals and awn growth and development was successfully reactivated on the rice spikelet by inactivating rice awn1 orthologue.Further RNA-seq and DAP-seq revealed that as a transcription repressor,AWN1 directly bound to the motif in the regulatory regions from three MADS genes related to flower development and two genes DL and LKS2 for the development of awn,downregulated the expressions of these genes,and then repressed the elongation of awn.The preexistence of regulatory elements in the neighbouring intergenic region of awn1 before domestication signified that noncoding DNA may serve as a treasure trove for evolution during adaptation to a changing world.Our results supported that gene duplication can promptly drive the evolution of gene regulatory network.展开更多
To understand the expansion ofmulticopy microRNA （miRNA） families in plants, we localized the reported miRNA genes from Arabidopsis and rice to their chromosomes, respectively, and observed that 37% of 117 miRNA gen...To understand the expansion ofmulticopy microRNA （miRNA） families in plants, we localized the reported miRNA genes from Arabidopsis and rice to their chromosomes, respectively, and observed that 37% of 117 miRNA genes from Arabidopsis and 35% of 173 miRNA genes from rice were segmental duplications in the genome. In order to characterize whether the expression diversification has occurred among plant multicopy miRNA family members, we designed PCR primers targeting 48 predicted miRNA precursors from 10 families in Arabidopsis and rice. Results from RT-PCR data suggest that the transcribed precursors of members within the same miRNA family were present at different expression levels. In addition, although miRl60 and miR162 sequences were conserved in Arabidopsis and rice, we found that the expression patterns of these genes differed between the two species. These data suggested that expression diversification has occurred in multicopy miRNA families, increasing our understanding of the expression regulation of miRNAs in plants.展开更多
Gene duplication provides raw genetic materials for evolution and potentially novel genes for crop improvement.The two seminal genomic studies of Aegilops tauschii both mentioned the large number of genes independentl...Gene duplication provides raw genetic materials for evolution and potentially novel genes for crop improvement.The two seminal genomic studies of Aegilops tauschii both mentioned the large number of genes independently duplicated in recent years,but the duplication mechanism and the evolutionary significance of these gene duplicates have not yet been investigated.Here,we found that a recent burst of gene duplications(hereafter abbreviated as the RBGD)has probably occurred in all sequenced Triticeae species.Further investigations of the characteristics of the gene duplicates and their flanking sequences suggested that transposable element(TE)activity may have been involved in generating the RBGD.We also characterized the duplication timing,retention pattern,diversification,and expression of the duplicates following the evolution of Triticeae.Multiple subgenome-specific comparisons of the duplicated gene pairs clearly supported extensive differential regulation and related functional diversity among such pairs in the three subgenomes of bread wheat.Moreover,several duplicated genes from the RBGD have evolved into key factors that influence important agronomic traits of wheat.Our results provide insights into a unique source of gene duplicates in Triticeae species,which has increased the gene dosage together with the two polyploidization events in the evolutionary history of wheat.展开更多
The black wolfberry(Lycium ruthenicum;2n=2x=24)is an important medicinal plant with ecological and economic value.Its fruits have numerous beneficial pharmacological activities,especially those of anthocyanins,polysac...The black wolfberry(Lycium ruthenicum;2n=2x=24)is an important medicinal plant with ecological and economic value.Its fruits have numerous beneficial pharmacological activities,especially those of anthocyanins,polysaccharides,and alkaloids,and have high nutritional value.However,the lack of available genomic resources for this species has hindered research on its medicinal and evolutionary mechanisms.In this study,we developed the telomere-to-telomere(T2T)nearly gapless genome of L.ruthenicum(2.26 Gb)by integrating PacBio HiFi,Nanopore Ultra-Long,and Hi-C technologies.The assembled genome comprised 12 chromosomes with 37,149 protein-coding genes functionally annotated.Approximately 80%of the repetitive sequences were identified,of which long terminal repeats(LTRs)were the most abundant,accounting for 73.01%.The abundance of LTRs might be the main reason for the larger genome of this species compared to that of other Lycium species.The species-specific genes of L.ruthenicum were related to defense mechanisms,salt tolerance,drought resistance,and oxidative stress,further demonstrating their superior adaptability to arid environments.Based on the assembled genome and fruit transcriptome data,we further constructed an anthocyanin biosynthesis pathway and identified 19 candidate structural genes and seven transcription factors that regulate anthocyanin biosynthesis in the fruit developmental stage of L.ruthenicum,most of which were highly expressed at a later stage in fruit development.Furthermore,154 potential disease resistance-related nucleotidebinding genes have been identified in the L.ruthenicum genome.The whole-genome and proximal,dispersed,and tandem duplication genes in the L.ruthenicum genome enriched the number of genes involved in anthocyanin synthesis and resistance-related pathways.These results provide an important genetic basis for understanding genome evolution and biosynthesis of pharmacologically active components in the Lycium genus.展开更多
Pigment accumulation is an important trait related to wheat domestication,but there remains a limited understanding of its molecular mechanism.The genetic control of the red glume trait by a dominant allele,Rg-B1,on 1...Pigment accumulation is an important trait related to wheat domestication,but there remains a limited understanding of its molecular mechanism.The genetic control of the red glume trait by a dominant allele,Rg-B1,on 1BS was reported in the last century,but the underlying gene and its molecular basis remained elusive.Here,we identified TraesTSP1B01G005700(G57)encoding an R2R3-MYB transcription factor(TF)as the candidate Rg-B1 gene controlling red glume color by a combination of genome-wide association study(GWAS),bulked segregant RNA-sequencing(BSR-Seq),map-based cloning,and RNAseq.The Rg-B1 locus had zero to five duplicate copies only one of which had high transcriptional activity.Genetic evidence suggested that promoter sequence variation in G57 in the glume leads to high expression of G57,resulting in the red glume phenotype.G57 could bind to the promoters of anthocyanin synthesis genes TaCHS,TaF3'H,and TaUFGT,activating their expression and contributing to anthocyanin accumulation in wheat glume.G57 also played a pivotal role in up-regulating expression of genes TaDREB1C and TaFLO2 associated with increased grain weight,thereby causing increased grain weight.Our research offers a better understanding of the molecular basis of red glume in bread wheat.展开更多
Nuclear factor Y(NF-Y) is a ubiquitous transcription factor that regulates important physiological and developmental processes. In this study, we identified 34 Os NF-Y genes in rice, including 6 newly identified genes...Nuclear factor Y(NF-Y) is a ubiquitous transcription factor that regulates important physiological and developmental processes. In this study, we identified 34 Os NF-Y genes in rice, including 6 newly identified genes. Expression profile analysis covering the whole life cycle revealed that transcripts of Os NF-Y differentially accumulated in a tissue-specific,preferential or constitutive manner. In addition, gene duplication studies and expression analyses were performed to determine the evolutionary origins of the Os NF-Y gene family.Nine Os NF-Y genes were differentially expressed after treatment of seedlings with one or more abiotic stresses such as drought, salt and cold. Analysis of expression correlation and Gene Ontology annotation suggested that Os NF-Y genes were co-expressed with genes that participated in stress, accumulation of seed storage reserves, and plant development.Co-expression analysis also revealed that Os NF-Y genes might interact with each other,suggesting that NF-Y subunits formed complexes that take part in transcriptional regulation. These results provide useful information for further elucidating the function of the NF-Y family and their regulatory pathways.展开更多
MicroRNAs (miRNAs) are 20-22 nucleotide non-coding RNAs that play important roles in plant and animal development. They are usually processed from larger precursors that can form stem-loop structures. Among 20 miRNA f...MicroRNAs (miRNAs) are 20-22 nucleotide non-coding RNAs that play important roles in plant and animal development. They are usually processed from larger precursors that can form stem-loop structures. Among 20 miRNA families that are conserved between Arabidopsis and rice, the rice miR395 gene family was unique because it was organized into compact clusters that could be transcribed as one single transcript. We show here that in fact this family had four clusters of total 24 genes. Three of these clusters were segmental duplications. They contained miR395 genes of both 120 bp and 66 bp long. However, only the latter was repeatedly duplicated. The fourth cluster contained miR395 genes of two different sizes that could be the consequences of intergenic recombination of genes from the first three clusters. On each cluster, both 1-duplication and 2-duplication histories were observed based on the sequence similarity between miR395 genes, some of which were nearly identical suggesting a recent origin. This was supported by a miR395 locus survey among several species of the genus Oryza, where two clusters were only found in species with an AA genome, the genome of the cultivated rice. A comparative study of the genomic organization of Medicago truncatula miR395 gene family showed significant expansion of intergenic spaces indicating that the originally clustered genes were drifting away from each other. The diverse genomic organizations of a conserved microRNA gene family in different plant genomes indicated that this important negative gene regulation system has undergone dramatic tune-ups in plant genomes.展开更多
The inherent interest on the origin of genetic novelties can be traced back to Darwin. But it was not until recently that we were allowed to investigate the fundamental process of origin of new genes by the studies on...The inherent interest on the origin of genetic novelties can be traced back to Darwin. But it was not until recently that we were allowed to investigate the fundamental process of origin of new genes by the studies on newly evolved young genes. Two indispensible steps are involved in this process： origin of new gene copies through various mutational mechanisms and evolution of novel functions, which fur- ther more leads to fixation of the new copies within populations. The theoretical framework for the former step formed in 1970s. Ohno proposed gene duplication as the most important mechanism producing new gene copies. He also believed that the most common fate for new gene copies is to become pseudogenes. This classical view was validated and was also challenged by the characterization of the first functional young gene jingwei in Drosophila. Recent genome-wide comparison on young genes of Drosophila has elucidated a compre- hensive picture addressing remarkable roles of various mechanisms besides gene duplication during origin of new genes. Case surveys revealed it is not rare that new genes would evolve novel structures and functions to contribute to the adaptive evolution of organisms. Here, we review recent advances in understanding how new genes originated and evolved on the basis of genome-wide results and ex- perimental efforts on cases. We would finally discuss the future directions of this fast-growing research field in the context of functional genomics era.展开更多
Apiaceae is a major family from Apiales and includes many important vegetable and medicinal crops.Heat shock transcription factors(Hsf)play important roles in heat tolerance during plant development.Here,we conducted ...Apiaceae is a major family from Apiales and includes many important vegetable and medicinal crops.Heat shock transcription factors(Hsf)play important roles in heat tolerance during plant development.Here,we conducted systematic analyses of the Hsf gene family in three Apiaceae species,including 17 Apium graveolens(celery),32 Coriandrum sativum(coriander),and 14 Daucus carota(carrot).A total of 73 Hsf genes were identified in three representative species,including Arabidopsis thaliana,Vitis vinifera,and Lactuca sativa.Whole-genome duplication played important roles in the Hsf gene family’s expansion within Apiaceae.Interestingly,we found that coriander had more Hsf genes than celery and carrot due to greater expansion and fewer losses.Twenty-seven branches of the phylogenetic tree underwent considerable positive selection in these Apiaceae species.We also explored the expression patterns of Hsf genes in three plant organs.Collectively,this study will serve as a rich gene resource for exploring the molecular mechanisms of heat tolerance.Additionally,this is the first study to report on the Hsf gene family in Apiaceae;thus,our research will provide guidance for future comparative and functional genomic studies on the Hsf gene family and others in Apiaceae.展开更多
基金funded by the Biotechnology and Biological Sciences Research Council(BBSRC) ERA-NET BB/G024995/1
文摘Since the first MADS-box transcription factor genes were implicated in the establishment of floral organ identity in a couple of model plants, the size and scope of this gene family has begun to be appreciated in a much wider range of species. Over the course of millions of years the number of MADS-box genes in plants has increased to the point that the Arabidopsis genome contains more than 100. The understanding gained from studying the evolution, regulation and function of multiple MADS-box genes in an increasing set of species, makes this large plant transcription factor gene family an ideal subject to study the processes that lead to an increase in gene number and the selective birth, death and repurposing of its component members. Here we will use examples taken from the MADS-box gene family to review what is known about the factors that influence the loss and retention of genes duplicated in different ways and examine the varied fates of the retained genes and their associated biological outcomes.
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences,China(XDB02010000)the National Natural Science Foundation of China(31530030 and 81371270)the Science and Technology Commission of Shanghai Municipality,China(16XD1404800)
文摘Autism spectrum disorder（ASD） encompasses a complex set of developmental neurological disorders,characterized by de？cits in social communication and excessive repetitive behaviors. In recent years, ASD is increasingly being considered as a disease of the synapse.One main type of genetic aberration leading to ASD is gene duplication, and several mouse models have been generated mimicking these mutations. Here, we studied the effects of MECP2 duplication and human chromosome15q11-13 duplication on synaptic development and neural circuit wiring in the mouse sensory cortices. We showed that mice carrying MECP2 duplication had speci？c defects in spine pruning, while the 15q11-13 duplication mouse model had impaired spine formation. Our results demonstrate that spine pathology varies signi？cantly between autism models and that distinct aspects of neural circuit development may be targeted in different ASD mutations.Our results further underscore the importance of gene dosage in normal development and function of the brain.
基金supported by the National Natural Science Foundation of China(No.31201713,No.31270425 and No.31470442)
文摘The worldwide declines in amphibian populations have largely been caused by infectious fungi and bacteria. Given that vertebrate immunity against these extracellular pathogens is primarily functioned by the major histocompatibility complex（MHC） class Ⅱ molecules, the characterization and the evolution of amphibian MHC class Ⅱ genes have attracted increasing attention. The polymorphism of MHC class Ⅱ genes was found to be correlated with susceptibility to fungal pathogens in many amphibian species, suggesting the importance of studies on MHC class Ⅱ genes for amphibians. However, such studies on MHC class Ⅱ gene evolution have rarely been conducted on amphibians in China. In this study, we chose Omei treefrog（Rhacophorus omeimontis）, which lived moist environments easy for breeding bacteria, to study the polymorphism of its MHC class Ⅱ genes and the underlying evolutionary mechanisms. We amplified the entire MHC class ⅡB exon 2 sequence in the R. omeimontis using newly designed primers. We detected 102 putative alleles in 146 individuals. The number of alleles per individual ranged from one to seven, indicating that there are at least four loci containing MHC class ⅡB genes in R. omeimontis. The allelic polymorphism estimated from the 102 alleles in R. omeimontis was not high compared to that estimated in other anuran species. No significant gene recombination was detected in the 102 MHC class ⅡB exon 2 sequences. In contrast, both gene duplication and balancing selection greatly contributed to the variability in MHC class ⅡB exon 2 sequences of R. omeimontis. This study lays the groundwork for the future researches to comprehensively analyze the evolution of amphibian MHC genes and to assess the role of MHC gene polymorphisms in resistance against extracellular pathogens for amphibians in China.
文摘Budding yeast (Saccharomyces cerevisiae) is a single cell model organism that is amenable to genome wide experimental interrogation using high-throughput genomics, proteomics
基金supported by the National Natural Science Foundation of China(81973422 and 31570302)the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(2021-I2M-1-071).
文摘Artemisia argyi Le´vl.et Vant.,a perennial Artemisia herb with an intense fragrance,is widely used in traditional medicine in China and many other Asian countries.Here,we present a chromosome-scale genome assembly of A.argyi comprising 3.89 Gb assembled into 17 pseudochromosomes.Phylogenetic and comparative genomic analyses revealed that A.argyi underwent a recent lineage-specificwhole-genomeduplication(WGD)event after divergence fromArtemisia annua,resulting in two subgenomes.Wedeciphered the diploid ancestral genome of A.argyi,and unbiased subgenome evolution was observed.The recent WGD led to a large number of duplicated genes in the A.argyi genome.Expansion of the terpene synthase(TPS)gene family through various types of gene duplication may have greatly contributed to the diversity of volatile terpenoids in A.argyi.In particular,we identified a typical germacrene D synthase gene cluster within the expanded TPS gene family.The entire biosynthetic pathways of germacrenes,(+)-borneol,and(+)-camphor were elucidated in A.argyi.In addition,partial deletion of the amorpha-4,11-diene synthase(ADS)gene and loss of function of ADS homologs may have resulted in the lack of artemisinin production in A.argyi.Our study provides newinsights into the genome evolution of Artemisia and lays a foundation for further improvement of the quality of this important medicinal plant.
基金This work was supported by the National Natural Science Foundation of China(92035302 and 31871632 to Z.L.)the National Key Research and Development Program of China(2016YFD0100303 and 2016YFD0101803 to Z.L.)the Chinese Universities Scientific Fund(2021TC065 to Z.L.).
文摘Loss of the awn in some cereals including sorghum is a key transition during cereal domestication or improvement that has facilitated grain harvest and storage.The genetic basis for the loss of awn in sorghum during domestication or improvement remains unknown.Here,we identified a transcription factor gene awn1 encoding an ALOG domain,which is responsible for awn loss during sorghum domestication or improvement.awn1 arose from a gene duplication from chromosome 10 that translocated to chromosome 3,recruiting a new promoter from the neighbouring intergenic region filled with"noncoding DNA",and recreating the first exon and intron.The awn1 acquires high expr`ession after duplication and represses the elongation of awns in domesticated sorghum.Comparative mapping revealed a high collinearity at awn1 paralog locus on chromosome 10 across cereals and awn growth and development was successfully reactivated on the rice spikelet by inactivating rice awn1 orthologue.Further RNA-seq and DAP-seq revealed that as a transcription repressor,AWN1 directly bound to the motif in the regulatory regions from three MADS genes related to flower development and two genes DL and LKS2 for the development of awn,downregulated the expressions of these genes,and then repressed the elongation of awn.The preexistence of regulatory elements in the neighbouring intergenic region of awn1 before domestication signified that noncoding DNA may serve as a treasure trove for evolution during adaptation to a changing world.Our results supported that gene duplication can promptly drive the evolution of gene regulatory network.
基金We acknowledge Prof HerváVaucheret for kindly supplying the agol-27 mutant and Dr Xuemei Chen for helpful suggestions and reviewing this manuscript.This work was supported by the Fund of National Key Basic Research Developments Program of the Ministry of Science and Technology China(2001CB109002)National Natural Science Foundation of China(30370893)+2 种基金Shanghai Municipal Committee of Science and Technology(03JC14061)the Program for New Century Excellent Talents in University(NCET-04-0403)the ShuGuang Scholarship(04SG15).
文摘To understand the expansion ofmulticopy microRNA （miRNA） families in plants, we localized the reported miRNA genes from Arabidopsis and rice to their chromosomes, respectively, and observed that 37% of 117 miRNA genes from Arabidopsis and 35% of 173 miRNA genes from rice were segmental duplications in the genome. In order to characterize whether the expression diversification has occurred among plant multicopy miRNA family members, we designed PCR primers targeting 48 predicted miRNA precursors from 10 families in Arabidopsis and rice. Results from RT-PCR data suggest that the transcribed precursors of members within the same miRNA family were present at different expression levels. In addition, although miRl60 and miR162 sequences were conserved in Arabidopsis and rice, we found that the expression patterns of these genes differed between the two species. These data suggested that expression diversification has occurred in multicopy miRNA families, increasing our understanding of the expression regulation of miRNAs in plants.
基金Wethank the National Natural Science Foundation of China(Grant number 31870209)the Key Science and Technology Program of Henan Prov-ince(201300110800)for research funding.
文摘Gene duplication provides raw genetic materials for evolution and potentially novel genes for crop improvement.The two seminal genomic studies of Aegilops tauschii both mentioned the large number of genes independently duplicated in recent years,but the duplication mechanism and the evolutionary significance of these gene duplicates have not yet been investigated.Here,we found that a recent burst of gene duplications(hereafter abbreviated as the RBGD)has probably occurred in all sequenced Triticeae species.Further investigations of the characteristics of the gene duplicates and their flanking sequences suggested that transposable element(TE)activity may have been involved in generating the RBGD.We also characterized the duplication timing,retention pattern,diversification,and expression of the duplicates following the evolution of Triticeae.Multiple subgenome-specific comparisons of the duplicated gene pairs clearly supported extensive differential regulation and related functional diversity among such pairs in the three subgenomes of bread wheat.Moreover,several duplicated genes from the RBGD have evolved into key factors that influence important agronomic traits of wheat.Our results provide insights into a unique source of gene duplicates in Triticeae species,which has increased the gene dosage together with the two polyploidization events in the evolutionary history of wheat.
基金supported by the National Natural Science Foundation of China(32360058)the Central Government Guides Local Science and Technology Development Projects,China(2023ZYZX1224)Xinjiang University Excellent Doctoral Student Innovation Project(XJU2022BS051)。
文摘The black wolfberry(Lycium ruthenicum;2n=2x=24)is an important medicinal plant with ecological and economic value.Its fruits have numerous beneficial pharmacological activities,especially those of anthocyanins,polysaccharides,and alkaloids,and have high nutritional value.However,the lack of available genomic resources for this species has hindered research on its medicinal and evolutionary mechanisms.In this study,we developed the telomere-to-telomere(T2T)nearly gapless genome of L.ruthenicum(2.26 Gb)by integrating PacBio HiFi,Nanopore Ultra-Long,and Hi-C technologies.The assembled genome comprised 12 chromosomes with 37,149 protein-coding genes functionally annotated.Approximately 80%of the repetitive sequences were identified,of which long terminal repeats(LTRs)were the most abundant,accounting for 73.01%.The abundance of LTRs might be the main reason for the larger genome of this species compared to that of other Lycium species.The species-specific genes of L.ruthenicum were related to defense mechanisms,salt tolerance,drought resistance,and oxidative stress,further demonstrating their superior adaptability to arid environments.Based on the assembled genome and fruit transcriptome data,we further constructed an anthocyanin biosynthesis pathway and identified 19 candidate structural genes and seven transcription factors that regulate anthocyanin biosynthesis in the fruit developmental stage of L.ruthenicum,most of which were highly expressed at a later stage in fruit development.Furthermore,154 potential disease resistance-related nucleotidebinding genes have been identified in the L.ruthenicum genome.The whole-genome and proximal,dispersed,and tandem duplication genes in the L.ruthenicum genome enriched the number of genes involved in anthocyanin synthesis and resistance-related pathways.These results provide an important genetic basis for understanding genome evolution and biosynthesis of pharmacologically active components in the Lycium genus.
基金supported by the National Natural Science Foundation of China(31991210)the National Key Research and Development Program of China(2021YFD1200104)。
文摘Pigment accumulation is an important trait related to wheat domestication,but there remains a limited understanding of its molecular mechanism.The genetic control of the red glume trait by a dominant allele,Rg-B1,on 1BS was reported in the last century,but the underlying gene and its molecular basis remained elusive.Here,we identified TraesTSP1B01G005700(G57)encoding an R2R3-MYB transcription factor(TF)as the candidate Rg-B1 gene controlling red glume color by a combination of genome-wide association study(GWAS),bulked segregant RNA-sequencing(BSR-Seq),map-based cloning,and RNAseq.The Rg-B1 locus had zero to five duplicate copies only one of which had high transcriptional activity.Genetic evidence suggested that promoter sequence variation in G57 in the glume leads to high expression of G57,resulting in the red glume phenotype.G57 could bind to the promoters of anthocyanin synthesis genes TaCHS,TaF3'H,and TaUFGT,activating their expression and contributing to anthocyanin accumulation in wheat glume.G57 also played a pivotal role in up-regulating expression of genes TaDREB1C and TaFLO2 associated with increased grain weight,thereby causing increased grain weight.Our research offers a better understanding of the molecular basis of red glume in bread wheat.
基金supported by the National Natural Science Foundation of China(Nos.31570321,30971551)
文摘Nuclear factor Y(NF-Y) is a ubiquitous transcription factor that regulates important physiological and developmental processes. In this study, we identified 34 Os NF-Y genes in rice, including 6 newly identified genes. Expression profile analysis covering the whole life cycle revealed that transcripts of Os NF-Y differentially accumulated in a tissue-specific,preferential or constitutive manner. In addition, gene duplication studies and expression analyses were performed to determine the evolutionary origins of the Os NF-Y gene family.Nine Os NF-Y genes were differentially expressed after treatment of seedlings with one or more abiotic stresses such as drought, salt and cold. Analysis of expression correlation and Gene Ontology annotation suggested that Os NF-Y genes were co-expressed with genes that participated in stress, accumulation of seed storage reserves, and plant development.Co-expression analysis also revealed that Os NF-Y genes might interact with each other,suggesting that NF-Y subunits formed complexes that take part in transcriptional regulation. These results provide useful information for further elucidating the function of the NF-Y family and their regulatory pathways.
基金supported in part by a grant from Northern Illinois University Foundation to Long MAONational Institutes of Health(NIH)grant to Mitrick JOHNS and Long MAO(No.44-G1A62164)a grant from the National Natural Science Foundation of China for oversea young scholars to Long MAO(No.30228022).
文摘MicroRNAs (miRNAs) are 20-22 nucleotide non-coding RNAs that play important roles in plant and animal development. They are usually processed from larger precursors that can form stem-loop structures. Among 20 miRNA families that are conserved between Arabidopsis and rice, the rice miR395 gene family was unique because it was organized into compact clusters that could be transcribed as one single transcript. We show here that in fact this family had four clusters of total 24 genes. Three of these clusters were segmental duplications. They contained miR395 genes of both 120 bp and 66 bp long. However, only the latter was repeatedly duplicated. The fourth cluster contained miR395 genes of two different sizes that could be the consequences of intergenic recombination of genes from the first three clusters. On each cluster, both 1-duplication and 2-duplication histories were observed based on the sequence similarity between miR395 genes, some of which were nearly identical suggesting a recent origin. This was supported by a miR395 locus survey among several species of the genus Oryza, where two clusters were only found in species with an AA genome, the genome of the cultivated rice. A comparative study of the genomic organization of Medicago truncatula miR395 gene family showed significant expansion of intergenic spaces indicating that the originally clustered genes were drifting away from each other. The diverse genomic organizations of a conserved microRNA gene family in different plant genomes indicated that this important negative gene regulation system has undergone dramatic tune-ups in plant genomes.
基金a CAS-Max Planck Society Fellowship, an award （No. 30325016）；the National Science Foundation of China （NSFC）,two NSFC key grants （No. 30430400 and 30623007）the National Basic Research Program of China （973 Program）（No. 2007CB815703-5）W.W., and a NSFC grant(No.30500283）for junior researchers to S.Y.
文摘The inherent interest on the origin of genetic novelties can be traced back to Darwin. But it was not until recently that we were allowed to investigate the fundamental process of origin of new genes by the studies on newly evolved young genes. Two indispensible steps are involved in this process： origin of new gene copies through various mutational mechanisms and evolution of novel functions, which fur- ther more leads to fixation of the new copies within populations. The theoretical framework for the former step formed in 1970s. Ohno proposed gene duplication as the most important mechanism producing new gene copies. He also believed that the most common fate for new gene copies is to become pseudogenes. This classical view was validated and was also challenged by the characterization of the first functional young gene jingwei in Drosophila. Recent genome-wide comparison on young genes of Drosophila has elucidated a compre- hensive picture addressing remarkable roles of various mechanisms besides gene duplication during origin of new genes. Case surveys revealed it is not rare that new genes would evolve novel structures and functions to contribute to the adaptive evolution of organisms. Here, we review recent advances in understanding how new genes originated and evolved on the basis of genome-wide results and ex- perimental efforts on cases. We would finally discuss the future directions of this fast-growing research field in the context of functional genomics era.
基金supported by the National Natural Science Foundation of China(Grant No.31801856)Hebei Province Higher Education Youth Talents Program(Grant No.BJ2018016)+1 种基金the China Postdoctoral Science Foundation(Grant No.2020M673188)the innovation and entrepreneurship training program for college students of North China University of Science and Technology(Grant No.X2019256).
文摘Apiaceae is a major family from Apiales and includes many important vegetable and medicinal crops.Heat shock transcription factors(Hsf)play important roles in heat tolerance during plant development.Here,we conducted systematic analyses of the Hsf gene family in three Apiaceae species,including 17 Apium graveolens(celery),32 Coriandrum sativum(coriander),and 14 Daucus carota(carrot).A total of 73 Hsf genes were identified in three representative species,including Arabidopsis thaliana,Vitis vinifera,and Lactuca sativa.Whole-genome duplication played important roles in the Hsf gene family’s expansion within Apiaceae.Interestingly,we found that coriander had more Hsf genes than celery and carrot due to greater expansion and fewer losses.Twenty-seven branches of the phylogenetic tree underwent considerable positive selection in these Apiaceae species.We also explored the expression patterns of Hsf genes in three plant organs.Collectively,this study will serve as a rich gene resource for exploring the molecular mechanisms of heat tolerance.Additionally,this is the first study to report on the Hsf gene family in Apiaceae;thus,our research will provide guidance for future comparative and functional genomic studies on the Hsf gene family and others in Apiaceae.
