RNA editing changes the nucleotides at the transcript level of mitochondrial genes which results in synthesis of functional proteins.This study was designed to find the editing sites which could be implicated in male ...RNA editing changes the nucleotides at the transcript level of mitochondrial genes which results in synthesis of functional proteins.This study was designed to find the editing sites which could be implicated in male fertility restoration and to develop editing based markers for differentiation of cytoplasmic male sterility and maintainer lines from each other.DNA and RNA from young panicles were isolated from three-line system of hybrid rice PRH10,wild abortive(WA)cytoplasm based male sterile(A line Pusa 6A),maintainer(B line Pusa 6B)and restorer(R line PRR78)lines.Pusa 6A and PRR78 having the same WA cytoplasm are allo-nuclear and iso-cytpolasmic lines.The genomic and cDNA amplicons for eight mitochondrial genes(18SrRNA,atp6,atp9,cobII,coxI,coxIII,nadI and rps3)were sequenced and compared.Differences in genomic and cDNA sequences were considered as editing.Two hundred and thirty editing sites having base substitution or insertion/deletion were identified with the highest in 18SrRNA(5.74%)and the lowest in coxI(0.60%).The highest editing sites were observed in fertile maintainer Pusa 6B followed by PRR78 and Pusa 6A,of which random five editing sites in five different rice mitochondrial transcripts namely atp9,cobII,coxIII,rps3 and 18SrRNA were chosen and validated through cleaved amplified polymorphism sequence(CAPS)analysis and found to be partially edited in four genes.The identical editing sites of different mitochondrial genes from maintainer and restorer lines might reflect their possible contribution to fertility restoration of sterile WA cytoplasm.展开更多
Apomixis is an asexual reproduction process in which clonal seeds are formed without meiosis and fertilization.Because of its potential in permanently preserving hybrid vigor,apomixis has attracted a great deal of int...Apomixis is an asexual reproduction process in which clonal seeds are formed without meiosis and fertilization.Because of its potential in permanently preserving hybrid vigor,apomixis has attracted a great deal of interests from plant biologists and the seed industry.However,despite of decades of effort,introgression of apomixis traits from wild relatives into major crops has remained unsuccessful.Therefore,synthetic apomixis has been proposed as an alternative to fix hybrid vigor.In this article,I present the development of the MiMe(Mitosis instead of Meiosis),which turns meiosis into mitosis and leads to the production of clonal gametes.Apomixis-like clonal seeds are generated when MiMe plants are crossed to special genome elimination lines,which contain an altered centromere-specific histone 3(CENH3).Furthermore,induction of haploid plants from egg cells can be achieved by either egg cell-specific expression of BABY BOOM1(BBM1),or disruption of MATRILINEAL(MTL)using CRISPR/Cas9 gene-editing technology.Synthetic apomixis is established and clonal seeds are produced by simultaneous engineering MiMe with altering BBM1 expression or MTL disruption.Finally,I discuss how to further improve the apomixis strategy and its applications in crop breeding.展开更多
The basic mechanism of heterosis has not been systematically and completely characterized.In previous studies,we obtained three economically important fishes that exhibit rapid growth,WR(WCC♀×RCC♂),WR-Ⅱ(WR♀&#...The basic mechanism of heterosis has not been systematically and completely characterized.In previous studies,we obtained three economically important fishes that exhibit rapid growth,WR(WCC♀×RCC♂),WR-Ⅱ(WR♀×WCC♂),and WR-Ⅲ(WR-Ⅱ♀×4nAU♂),through distant hybridization.However,the mechanism underlying this rapid growth remains unclear.In this study,we found that WR,WR-Ⅱ,and WR-Ⅲshowed muscle hypertrophy and higher muscle protein and fat contents compared with their parent species(RCC and WCC).Candidate genes responsible for this rapid growth were then obtained through an analysis of 12 muscle transcriptomes.Notably,the mRNA level of mstnb(myostatin b),which is a negative regulator of myogenesis,was significantly reduced in WR,WR-Ⅱ,and WR-Ⅲcompared with the parent species.To verify the function of mstnb,a mstnb-deficient mutant RCC line was generated using the CRISPR-Cas9 technique.The average body weight of mstnb-deficient RCC at 12 months of age was significantly increased by 29.57%compared with that in wild-type siblings.Moreover,the area and number of muscle fibers were significantly increased in mstnb-deficient RCC,indicating hypertrophy and hyperplasia.Furthermore,the muscle protein and fat contents were significantly increased in mstnb-deficient RCC.The molecular regulatory mechanism of mstnb was then revealed by transcription profiling,which showed that genes related to myogenesis(myod,myog,and myf5),protein synthesis(PI3K-AKT-mTOR),and lipogenesis(pparγand fabp3)were highly activated in hybrid fishes and mstnb-deficient RCC.This study revealed that low expression or deficiency of mstnb regulates somatic growth by promoting myogenesis,protein synthesis,and lipogenesis in hybrid fishes and mstnb-deficient RCC,which provides evidence for the molecular mechanism of heterosis via distant hybridization.展开更多
文摘RNA editing changes the nucleotides at the transcript level of mitochondrial genes which results in synthesis of functional proteins.This study was designed to find the editing sites which could be implicated in male fertility restoration and to develop editing based markers for differentiation of cytoplasmic male sterility and maintainer lines from each other.DNA and RNA from young panicles were isolated from three-line system of hybrid rice PRH10,wild abortive(WA)cytoplasm based male sterile(A line Pusa 6A),maintainer(B line Pusa 6B)and restorer(R line PRR78)lines.Pusa 6A and PRR78 having the same WA cytoplasm are allo-nuclear and iso-cytpolasmic lines.The genomic and cDNA amplicons for eight mitochondrial genes(18SrRNA,atp6,atp9,cobII,coxI,coxIII,nadI and rps3)were sequenced and compared.Differences in genomic and cDNA sequences were considered as editing.Two hundred and thirty editing sites having base substitution or insertion/deletion were identified with the highest in 18SrRNA(5.74%)and the lowest in coxI(0.60%).The highest editing sites were observed in fertile maintainer Pusa 6B followed by PRR78 and Pusa 6A,of which random five editing sites in five different rice mitochondrial transcripts namely atp9,cobII,coxIII,rps3 and 18SrRNA were chosen and validated through cleaved amplified polymorphism sequence(CAPS)analysis and found to be partially edited in four genes.The identical editing sites of different mitochondrial genes from maintainer and restorer lines might reflect their possible contribution to fertility restoration of sterile WA cytoplasm.
基金This study was supported by the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.
文摘Apomixis is an asexual reproduction process in which clonal seeds are formed without meiosis and fertilization.Because of its potential in permanently preserving hybrid vigor,apomixis has attracted a great deal of interests from plant biologists and the seed industry.However,despite of decades of effort,introgression of apomixis traits from wild relatives into major crops has remained unsuccessful.Therefore,synthetic apomixis has been proposed as an alternative to fix hybrid vigor.In this article,I present the development of the MiMe(Mitosis instead of Meiosis),which turns meiosis into mitosis and leads to the production of clonal gametes.Apomixis-like clonal seeds are generated when MiMe plants are crossed to special genome elimination lines,which contain an altered centromere-specific histone 3(CENH3).Furthermore,induction of haploid plants from egg cells can be achieved by either egg cell-specific expression of BABY BOOM1(BBM1),or disruption of MATRILINEAL(MTL)using CRISPR/Cas9 gene-editing technology.Synthetic apomixis is established and clonal seeds are produced by simultaneous engineering MiMe with altering BBM1 expression or MTL disruption.Finally,I discuss how to further improve the apomixis strategy and its applications in crop breeding.
基金supported by the National Natural Science Foundation of China(32002382,32293252,U19A2040,32293254)the National Key Research and Development Program of China(2023YFD2400202)+5 种基金the Natural Science Foundation of Hunan Province(2021JJ40339)the Training Program for Excellent Young Innovators of Changsha(kq2209013)the Earmarked Fund for Agriculture Research System of China(CARS-45)the Laboratory of Lingnan Modern Agriculture Project(NT2021008)the 111 Project(D20007)Special Science Found of Nansha-South China Agricultural University Fishery Research Institute,Guangzhou。
文摘The basic mechanism of heterosis has not been systematically and completely characterized.In previous studies,we obtained three economically important fishes that exhibit rapid growth,WR(WCC♀×RCC♂),WR-Ⅱ(WR♀×WCC♂),and WR-Ⅲ(WR-Ⅱ♀×4nAU♂),through distant hybridization.However,the mechanism underlying this rapid growth remains unclear.In this study,we found that WR,WR-Ⅱ,and WR-Ⅲshowed muscle hypertrophy and higher muscle protein and fat contents compared with their parent species(RCC and WCC).Candidate genes responsible for this rapid growth were then obtained through an analysis of 12 muscle transcriptomes.Notably,the mRNA level of mstnb(myostatin b),which is a negative regulator of myogenesis,was significantly reduced in WR,WR-Ⅱ,and WR-Ⅲcompared with the parent species.To verify the function of mstnb,a mstnb-deficient mutant RCC line was generated using the CRISPR-Cas9 technique.The average body weight of mstnb-deficient RCC at 12 months of age was significantly increased by 29.57%compared with that in wild-type siblings.Moreover,the area and number of muscle fibers were significantly increased in mstnb-deficient RCC,indicating hypertrophy and hyperplasia.Furthermore,the muscle protein and fat contents were significantly increased in mstnb-deficient RCC.The molecular regulatory mechanism of mstnb was then revealed by transcription profiling,which showed that genes related to myogenesis(myod,myog,and myf5),protein synthesis(PI3K-AKT-mTOR),and lipogenesis(pparγand fabp3)were highly activated in hybrid fishes and mstnb-deficient RCC.This study revealed that low expression or deficiency of mstnb regulates somatic growth by promoting myogenesis,protein synthesis,and lipogenesis in hybrid fishes and mstnb-deficient RCC,which provides evidence for the molecular mechanism of heterosis via distant hybridization.
