Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information conce...Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information concerning the inversion. The present study re- ports a transgenic rice line selected from a T-DNA tagged population, which displays a semi-dwarf phenotype. Molecular analysis of this mutant indicated an insertion of two tandem copies of T-DNA into a locus on the rice genome in a head to tail mode. This insertion of T-DNA resulted in the inversion of a 4.9 Mb chromosomal segment. Results of sequence analysis suggest that the chromosomal inversion resulted from the insertion of T-DNA with the help of sequence microhomology between insertion region of T-DNA and target sequence of the host plant.展开更多
Biosynthetic gene clusters(BGCs)are regions of a genome where genes involved in a biosynthetic pathway are in proximity.The origin and evolution of plant BGCs as well as their role in specialized metabolism remain lar...Biosynthetic gene clusters(BGCs)are regions of a genome where genes involved in a biosynthetic pathway are in proximity.The origin and evolution of plant BGCs as well as their role in specialized metabolism remain largely unclear.In this study,we have assembled a chromosome-scale genome of Japanese catnip(Schizonepeta tenuifolia)and discovered a BGC that contains multiple copies of genes involved in four adjacent steps in the biosynthesis of p-menthane monoterpenoids.This BGC has an unprecedented bipartite structure,with mirrored biosynthetic regions separated by 260 kilobases.This bipartite BGC includes identical copies of a gene encoding an old yellow enzyme,a type of flavin-dependent reductase.In vitro assays and virus-induced gene silencing revealed that this gene encodes the missing isopiperitenone reductase.This enzyme evolved from a completely different enzyme family to isopiperitenone reductase from closely related Mentha spp.,indicating convergent evolution of this pathway step.Phylogenomic analysis revealed that this bipartite BGC has emerged uniquely in the S.tenuifolia lineage and through insertion of pathway genes into a region rich in monoterpene synthases.The cluster gained its bipartite structure via an inverted duplication.The discovered bipartite BGC for p-menthane biosynthesis in S.tenuifolia has similarities to the recently described duplicated p-menthane biosynthesis gene pairs in the Mentha longifolia genome,providing an example of the convergent evolution of gene order.This work expands our understanding of plant BGCs with respect to both form and evolution,and highlights the power of BGCs for gene discovery in plant biosynthetic pathways.展开更多
Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16.To fine-map the YR86 locus,we developed two large F2 populations...Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16.To fine-map the YR86 locus,we developed two large F2 populations from crosses Emai 580/Zhongmai 895 and Avocet S/Zhongmai 895.Remarkably,both populations exhibited suppressed recombination in the same 2AL region.Collinearity analysis across Chinese Spring,Aikang 58,and 10+wheat genomes revealed a 4.1 Mb chromosomal inversion spanning 708.5-712.6 Mb in the Chinese Spring reference genome.Molecular markers were developed in the breakpoint and were used to assess a wheat cultivar panel,revealing that Chinese Spring,Zhongmai 895,and Jimai 22 shared a common sequence named InvCS,whereas Aikang 58,Yangmai 16,Emai 580,and Avocet S shared the sequence named InvAK58.The inverted configuration explained the suppressed recombination observed in all three bi-parental populations.Normal recombination was observed in a Jimai 22/Zhongmai 895 F2 population,facilitating mapping of YR86 to a genetic interval of 0.15 cM corresponding to 710.27-712.56 Mb falling within the inverted region.Thirty-three high-confidence genes were annotated in the interval using the Chinese Spring reference genome,with six identified as potential candidates for YR86 based on genome and transcriptome analyses.These results will accelerate map-based cloning of YR86 and its deployment in wheat breeding.展开更多
In the last years,tremendous progress has been achieved in the field of gene editing in plants.By the induction of single site-specific double-strand breaks(DSBs),the knockout of genes by non-homologous end joining ha...In the last years,tremendous progress has been achieved in the field of gene editing in plants.By the induction of single site-specific double-strand breaks(DSBs),the knockout of genes by non-homologous end joining has become routine in many plant species.Recently,the efficiency of inducing pre-planned mutations by homologous recombination has also been improved considerably.However,very little effort has been undertaken until now to achieve more complex changes in plant genomes by the simultaneous induction of several DSBs.Several reports have been published on the efficient induction of deletions.However,the induction of intrachromosomal inversions and interchromosomal recombination by the use of CRISPR/Cas has only recently been reported.In this review,we want to sum up these results and put them into context with regards to what is known about natural chromosome rearrangements in plants.Moreover,we review the recent progress in CRISPR/Cas-based mammalian chromosomal rearrangements,which might be inspiring for plant biologists.In the long run,the controlled restructuring of plant genomes should enable us to link or break linkage of traits at will,thus defining a new area of plant breeding.展开更多
Objective To examine the relationship between spontaneous abortion and chromosomal abnormalities.Methods Couples who had one or more consecutive spontaneous abortions and had normal genitals were enrolled for cytoge...Objective To examine the relationship between spontaneous abortion and chromosomal abnormalities.Methods Couples who had one or more consecutive spontaneous abortions and had normal genitals were enrolled for cytogenetic karyotype analysis. Results In the 61 couples, the detected incidence was 11.5%, with five Robertsonian translocations, one reciprocal translocation, and one pericentric inversion of chromosome 7. Conclusion Chromosomal abnormalities may play an important role in fetal wastage.展开更多
基金supported by the National High Technology Development Program of China (No.2008AA10Z104)China Postdoctoral Science Foundation (No.20060600519)
文摘Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information concerning the inversion. The present study re- ports a transgenic rice line selected from a T-DNA tagged population, which displays a semi-dwarf phenotype. Molecular analysis of this mutant indicated an insertion of two tandem copies of T-DNA into a locus on the rice genome in a head to tail mode. This insertion of T-DNA resulted in the inversion of a 4.9 Mb chromosomal segment. Results of sequence analysis suggest that the chromosomal inversion resulted from the insertion of T-DNA with the help of sequence microhomology between insertion region of T-DNA and target sequence of the host plant.
基金supported by the National Natural Science Foundation of China(grant nos.81973435 and 81473313)the National Natural Science Foundation for Young Scientists of China(grant no.81903756)+2 种基金the Open Project of the Natural Science Foundation of Nanjing University of Chinese Medicine(no.NZY81903756)research on ecological planting and quality assurance of Jiangsu Dao-di herbs(2021)and a Jiangsu Government Scholarship for Overseas Studies(JS-2020-044).We also acknowledge support from the BBSRC(BBN006452/1)and UKRI(MR/S01862X/1).
文摘Biosynthetic gene clusters(BGCs)are regions of a genome where genes involved in a biosynthetic pathway are in proximity.The origin and evolution of plant BGCs as well as their role in specialized metabolism remain largely unclear.In this study,we have assembled a chromosome-scale genome of Japanese catnip(Schizonepeta tenuifolia)and discovered a BGC that contains multiple copies of genes involved in four adjacent steps in the biosynthesis of p-menthane monoterpenoids.This BGC has an unprecedented bipartite structure,with mirrored biosynthetic regions separated by 260 kilobases.This bipartite BGC includes identical copies of a gene encoding an old yellow enzyme,a type of flavin-dependent reductase.In vitro assays and virus-induced gene silencing revealed that this gene encodes the missing isopiperitenone reductase.This enzyme evolved from a completely different enzyme family to isopiperitenone reductase from closely related Mentha spp.,indicating convergent evolution of this pathway step.Phylogenomic analysis revealed that this bipartite BGC has emerged uniquely in the S.tenuifolia lineage and through insertion of pathway genes into a region rich in monoterpene synthases.The cluster gained its bipartite structure via an inverted duplication.The discovered bipartite BGC for p-menthane biosynthesis in S.tenuifolia has similarities to the recently described duplicated p-menthane biosynthesis gene pairs in the Mentha longifolia genome,providing an example of the convergent evolution of gene order.This work expands our understanding of plant BGCs with respect to both form and evolution,and highlights the power of BGCs for gene discovery in plant biosynthetic pathways.
基金financially supported by the National Key Research and Development Program of China (2022YFD1200900 and 2022YFD1200904)the Agricultural Science and Technology Innovation Program+1 种基金Fundamental Research Funds for Central NonProfit of Institute of Crop Sciences, CAASShijiazhuang S&T Project (232490022A and 232490432A)
文摘Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16.To fine-map the YR86 locus,we developed two large F2 populations from crosses Emai 580/Zhongmai 895 and Avocet S/Zhongmai 895.Remarkably,both populations exhibited suppressed recombination in the same 2AL region.Collinearity analysis across Chinese Spring,Aikang 58,and 10+wheat genomes revealed a 4.1 Mb chromosomal inversion spanning 708.5-712.6 Mb in the Chinese Spring reference genome.Molecular markers were developed in the breakpoint and were used to assess a wheat cultivar panel,revealing that Chinese Spring,Zhongmai 895,and Jimai 22 shared a common sequence named InvCS,whereas Aikang 58,Yangmai 16,Emai 580,and Avocet S shared the sequence named InvAK58.The inverted configuration explained the suppressed recombination observed in all three bi-parental populations.Normal recombination was observed in a Jimai 22/Zhongmai 895 F2 population,facilitating mapping of YR86 to a genetic interval of 0.15 cM corresponding to 710.27-712.56 Mb falling within the inverted region.Thirty-three high-confidence genes were annotated in the interval using the Chinese Spring reference genome,with six identified as potential candidates for YR86 based on genome and transcriptome analyses.These results will accelerate map-based cloning of YR86 and its deployment in wheat breeding.
基金This work was supported by the European Research Council(Grant number ERC-2016-AdG_741306 CRISBREED).
文摘In the last years,tremendous progress has been achieved in the field of gene editing in plants.By the induction of single site-specific double-strand breaks(DSBs),the knockout of genes by non-homologous end joining has become routine in many plant species.Recently,the efficiency of inducing pre-planned mutations by homologous recombination has also been improved considerably.However,very little effort has been undertaken until now to achieve more complex changes in plant genomes by the simultaneous induction of several DSBs.Several reports have been published on the efficient induction of deletions.However,the induction of intrachromosomal inversions and interchromosomal recombination by the use of CRISPR/Cas has only recently been reported.In this review,we want to sum up these results and put them into context with regards to what is known about natural chromosome rearrangements in plants.Moreover,we review the recent progress in CRISPR/Cas-based mammalian chromosomal rearrangements,which might be inspiring for plant biologists.In the long run,the controlled restructuring of plant genomes should enable us to link or break linkage of traits at will,thus defining a new area of plant breeding.
文摘Objective To examine the relationship between spontaneous abortion and chromosomal abnormalities.Methods Couples who had one or more consecutive spontaneous abortions and had normal genitals were enrolled for cytogenetic karyotype analysis. Results In the 61 couples, the detected incidence was 11.5%, with five Robertsonian translocations, one reciprocal translocation, and one pericentric inversion of chromosome 7. Conclusion Chromosomal abnormalities may play an important role in fetal wastage.
