[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.Fals...[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.False positive was identified by PCR and then removed.Mice were infected to detect the virulence of mutants.The bionomics of attenuated strains were detected,too.[Result] The attenuated mutants showed similar reproductive activity to that of wild strain.The virulence of mutants was still stable after 30 passages.[Conclusion] This study provided foundation for exploring the virulence factors and pathogenic mechanism of HPS.展开更多
Dear Editor,Cucumber,Cucumis sativus,is a major vegetable crop globally.In addition to being consumed fresh or sliced,pickling cucumber represents a key cultivated type,widely grown in open fields across regions inclu...Dear Editor,Cucumber,Cucumis sativus,is a major vegetable crop globally.In addition to being consumed fresh or sliced,pickling cucumber represents a key cultivated type,widely grown in open fields across regions including the Americas,Europe,and Asia(Shetty and Wehner,2002).展开更多
Watermelon,Citrullus lanatus,is the world's third largest fruit crop.Reference genomes with gaps and a narrow genetic base hinder functional genomics and genetic improvement of watermelon.Here,we report the assemb...Watermelon,Citrullus lanatus,is the world's third largest fruit crop.Reference genomes with gaps and a narrow genetic base hinder functional genomics and genetic improvement of watermelon.Here,we report the assembly of a telomere-to-telomere gap-free genome of the elite watermelon inbred line G42 by incorporating high-coverage and accurate long-read sequencing data with multiple assembly strategies.All 11 chromosomes have been assembled into single-contig pseudomolecules without gaps,representing the highest completeness and assembly quality to date.The G42 reference genome is 369321829 bp in length and contains 24205 predicted protein-coding genes,with all 22 telomeres and 11 centromeres characterized.Furthermore,we established a pollen-EMS mutagenesis protocol and obtained over 200000M1 seeds from G42.In a sampling pool,48 monogenic phenotypic mutations,selected from 223M1and 78 M2 mutants with morphological changes,were confirmed.The average mutation density was 1 SNP/1.69Mband1 indel/4.55 Mb per M1 plant and 1SNP/1.08Mb and 1 indel/6.25 Mb per M2 plant.Taking advantage of the gap-free G42 genome,8039 mutations from 32 plants sampled from M1 and M2 families were identified with 100%accuracy,whereas only 25% of the randomly selected mutations identified using the 97103v2 reference genome could be confirmed.Using this library and the gap-free genome,two genes responsible for elongated fruit shape and male sterility(CiMs1)were identified,both caused by a single basechange from G to A.The validated gap-free genome and its EMS mutation library provide invaluable resources for functional genomics and genetic improvement of watermelon.展开更多
Sorghum,the fifth most important food crop globally,is a source of silage forage,fiber,syrup,and biofuel.Moreover,it is widely recognized as an ideal model crop for studying stress biology becaused of its ability to t...Sorghum,the fifth most important food crop globally,is a source of silage forage,fiber,syrup,and biofuel.Moreover,it is widely recognized as an ideal model crop for studying stress biology becaused of its ability to tolerate multiple abiotic stresses,including high salt-alkali conditions,drought,and heat.However,functional genomics studies on sorghum have been challenging,primarily due to the limited availability of genetic resources and effective genetic transformation techniques.In this study,we developed the Sorghum Genomics and Mutation Database(SGMD),aiming to advance the genetic understanding of sorghum.Our effort encompassed a telomere-to-telomere genome assembly of an inbred sorghum line,E048,yielding 729.46 Mb of sequence data representing the complete genome.Alongside the high-quality sequence data,a gene expression atlas covering 13 distinct tissues was developed.We constructed a saturated ethyl methane sulfonate mutant library comprising 13,226 independent mutants.Causal genes in chlorosis and leafy mutants from the library were easily identified by leveraging the MutMap and MutMap+methodologies,demonstrating the powerful application of this library for identifying functional genes.To facilitate sorghum research,we performed whole-genome sequencing of 179 M2 mutant lines,resulting in 2,291,074 mutations that covered 97.54% of all genes.In addition,an Agrobacterium-mediated sorghum transformation platform was established for gene function studies.In summary,this work establishes a comprehensive platform and provides valuable resources for functional genomics investigations and genetic improvement of sorghum.展开更多
基金Supported by National High Technology Research and Development Program of China(2006AA10A206)National Natural Science Foundation of China(31001072)the Fund of Beijing Academy of Agriculture and Forestry Sciences for Young Scholars(QNJJ201012)~~
文摘[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.False positive was identified by PCR and then removed.Mice were infected to detect the virulence of mutants.The bionomics of attenuated strains were detected,too.[Result] The attenuated mutants showed similar reproductive activity to that of wild strain.The virulence of mutants was still stable after 30 passages.[Conclusion] This study provided foundation for exploring the virulence factors and pathogenic mechanism of HPS.
基金supported by the Provincial Technology Innovation Program of Shandong,Ningbo Science and Technology Innovation Project 2021Z132Weifang Seed Innovation Group.
文摘Dear Editor,Cucumber,Cucumis sativus,is a major vegetable crop globally.In addition to being consumed fresh or sliced,pickling cucumber represents a key cultivated type,widely grown in open fields across regions including the Americas,Europe,and Asia(Shetty and Wehner,2002).
基金This work was supported by the Provincial Technology Innovation Program of Shandong,Ningxia Hui Autonomous Region agricultural breeding special project(NXNYYZ202001)Jiangsu Seed Industry Revitalization Competitive Project JBGS(2021)072,Ningbo Science and Technology Innovation Project 2021Z132,and Weifang Seed InnovationGroup.
文摘Watermelon,Citrullus lanatus,is the world's third largest fruit crop.Reference genomes with gaps and a narrow genetic base hinder functional genomics and genetic improvement of watermelon.Here,we report the assembly of a telomere-to-telomere gap-free genome of the elite watermelon inbred line G42 by incorporating high-coverage and accurate long-read sequencing data with multiple assembly strategies.All 11 chromosomes have been assembled into single-contig pseudomolecules without gaps,representing the highest completeness and assembly quality to date.The G42 reference genome is 369321829 bp in length and contains 24205 predicted protein-coding genes,with all 22 telomeres and 11 centromeres characterized.Furthermore,we established a pollen-EMS mutagenesis protocol and obtained over 200000M1 seeds from G42.In a sampling pool,48 monogenic phenotypic mutations,selected from 223M1and 78 M2 mutants with morphological changes,were confirmed.The average mutation density was 1 SNP/1.69Mband1 indel/4.55 Mb per M1 plant and 1SNP/1.08Mb and 1 indel/6.25 Mb per M2 plant.Taking advantage of the gap-free G42 genome,8039 mutations from 32 plants sampled from M1 and M2 families were identified with 100%accuracy,whereas only 25% of the randomly selected mutations identified using the 97103v2 reference genome could be confirmed.Using this library and the gap-free genome,two genes responsible for elongated fruit shape and male sterility(CiMs1)were identified,both caused by a single basechange from G to A.The validated gap-free genome and its EMS mutation library provide invaluable resources for functional genomics and genetic improvement of watermelon.
基金supported by the National Natural Science Foundation of ChinaNational Natural Science Foundation of China(32241042,32430077,32222010,and 32241038)and Chinese Universities Scientific Fund Chinese Universities Scientific Fund grant(1201-—15054001).
文摘Sorghum,the fifth most important food crop globally,is a source of silage forage,fiber,syrup,and biofuel.Moreover,it is widely recognized as an ideal model crop for studying stress biology becaused of its ability to tolerate multiple abiotic stresses,including high salt-alkali conditions,drought,and heat.However,functional genomics studies on sorghum have been challenging,primarily due to the limited availability of genetic resources and effective genetic transformation techniques.In this study,we developed the Sorghum Genomics and Mutation Database(SGMD),aiming to advance the genetic understanding of sorghum.Our effort encompassed a telomere-to-telomere genome assembly of an inbred sorghum line,E048,yielding 729.46 Mb of sequence data representing the complete genome.Alongside the high-quality sequence data,a gene expression atlas covering 13 distinct tissues was developed.We constructed a saturated ethyl methane sulfonate mutant library comprising 13,226 independent mutants.Causal genes in chlorosis and leafy mutants from the library were easily identified by leveraging the MutMap and MutMap+methodologies,demonstrating the powerful application of this library for identifying functional genes.To facilitate sorghum research,we performed whole-genome sequencing of 179 M2 mutant lines,resulting in 2,291,074 mutations that covered 97.54% of all genes.In addition,an Agrobacterium-mediated sorghum transformation platform was established for gene function studies.In summary,this work establishes a comprehensive platform and provides valuable resources for functional genomics investigations and genetic improvement of sorghum.
