The haploid-inducing line Stock 6 was used to produce haploid maize and expected to obtain maize haploid plants successfully. The detailed meiotic studies on selected haploid maize （n = x = 10） were conducted. Cytog...The haploid-inducing line Stock 6 was used to produce haploid maize and expected to obtain maize haploid plants successfully. The detailed meiotic studies on selected haploid maize （n = x = 10） were conducted. Cytogenetic analysis revealed a high frequency of meiotic abnormality occurred in both meiosis Ⅰ and meiosis Ⅱ. During the prophase Ⅰ, univalents were common configurations, and there were bivalents or trivalents in some pollen mother cells, however, a few cells containing five bivalents were also observed. After prophase Ⅰ, chromosomes did not congregate in a single metaphase plate but they were scattered in the cytoplasm. At anaphase Ⅰ, the chromosome distribution was highly irregular with almost all possible combinations. In some cells, chromosomes were grouped into the three or four masses and several spindles appeared. At the tetrad stage of meiosis Ⅱ, eytokinesis splitting abnormality occurred, and a variety of diad, triad, tetrad, pentad, hexad, as well as decury microspores were easily observed. As a consequence of abnormalities of the two meiotic stages, various microspores and the pollen were almost completely sterile. grains with different size were formed, and its pollen grains展开更多
AIM To prepare a Gpm6a/Reelin^(GFPCreERT2) construct with a rapid and reliable strategy using a bacterial artificial chromosome(BAC). METHODS Gpm6 a and Reelin BACs were purified and transformed into SW102 E. coli by ...AIM To prepare a Gpm6a/Reelin^(GFPCreERT2) construct with a rapid and reliable strategy using a bacterial artificial chromosome(BAC). METHODS Gpm6 a and Reelin BACs were purified and transformed into SW102 E. coli by electroporation. The GFPCreE RT2 fragment was prepared from a shuttle vector and transformed into SW102 E. coli carrying a BAC. Homologous recombination was induced in SW102 E. coli. Recombinant clones were screened and confirmed by PCR and restriction enzyme digestion. Recombinant clones were transformed into SW102 E. coli to remove the kanamycin unit.RESULTS A complete BAC was successfully transformed into SW102 E. coli by electroporation because BAC purified from SW102 E. coli showed the same pattern as the original BAC with Bam H I digestion. The GFPCre ERT2 fragment was deemed to have been prepared successfully because we obtained the same size fragment as expected. Homologous recombination was induced, and GFPCre ERT2 was deemed to have been inserted into the correct site of the BAC because we found the band change was the same as the expected pattern after restriction enzyme digestion. The kanamycin unit was deemed to have been removed successfully because we obtained different sizes of bands that were consistent with the results expected by PCR with different primers. CONCLUSION The construct of Gpm6 a^(GFPCreERT2) or Reelin^(GFPCreERT2) was prepared successfully, which will establish a foundation for tracing the hepatic stellate cell lineage and studying its function.展开更多
To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent paren...To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent parent Yangmal 5 to Isolate the resistance relative genes. A cDNA fragment specifically expressed in the resistant line was obtained and its full length was cloned by in silico cloning and RT-PCR. This gene encoded a deduced protein of 219 amino acids with a leucine-rich repeat （LRR） motif, often found In plant resistance genes, and was designated as Ta-LRR2. Ta-LRR2 had an increased expression level in the resistant line after Inoculation with Erysiphe graminis DC. f. sp. tritici Marchal. PCR analysis with different cytogenetlc stocks suggested that Ta-LRR2 was specifically associated with chromosome arms 6VS and 6AS. Linkage analysis further showed that Ta-LRR2 could be used as a resistance gene analog polymorphism marker of Pm21 for marker-assisted selection in germplasm enhancement and breeding practice. Moreover, how to Isolate Pm21 based on the Information obtained for Ta-LRR2 is discussed.展开更多
This study was undertaken to dissect quantitative trait loci （QTLs） controlling yield traits on the short arm of rice chromosome 6. A residual heterozygous line that carries a heterozygous segment extending from RM5...This study was undertaken to dissect quantitative trait loci （QTLs） controlling yield traits on the short arm of rice chromosome 6. A residual heterozygous line that carries a heterozygous segment extending from RM587 to RM19784 on the short arm of rice chromosome 6 was selected from an F7 population of the indica rice cross Zhenshan 97B/Milyang 46. An F2：3 population consisting of 221 lines was derived and grown in two trial sites. Six yield traits including number of panicles per plant, number of filled grains per panicle, total number of spikelets per panicle, spikelet fertility, 1 000-grain weight, and grain yield per plant were measured. An SSR marker linkage map was constructed and employed to determine QTLs for yield traits with Windows QTL Cartographer 2.5. QTLs were detected in the target interval for all the traits analyzed except NP, with phenotypic variance explained by a single QTL ranging between 6.3% and 35.2%. Most of the QTLs for yield components acted as additive QTLs, while the three QTLs for grain yield had dominance degrees of 1.65, 0.84, and -0.42, respectively. It was indicated that three or more QTLs for yield traits were located in the target region. The genetic action mode, the direction of the QTL effect, and the magnitude of the QTL effect varied among different QTLs for a given trait, and among QTLs for different traits that were located in the same interval.展开更多
基金supported by the National 973 Program of China (2007CB108900)the National Natural Science Foundation of China (30671308)+2 种基金SichuanYouth Science and Technology Fund, China (2007Q14-032)Ministry of Education Innovation Team Development Plan, China (IRT0453)Sichuan Forage Grass Breeding Project, China
文摘The haploid-inducing line Stock 6 was used to produce haploid maize and expected to obtain maize haploid plants successfully. The detailed meiotic studies on selected haploid maize （n = x = 10） were conducted. Cytogenetic analysis revealed a high frequency of meiotic abnormality occurred in both meiosis Ⅰ and meiosis Ⅱ. During the prophase Ⅰ, univalents were common configurations, and there were bivalents or trivalents in some pollen mother cells, however, a few cells containing five bivalents were also observed. After prophase Ⅰ, chromosomes did not congregate in a single metaphase plate but they were scattered in the cytoplasm. At anaphase Ⅰ, the chromosome distribution was highly irregular with almost all possible combinations. In some cells, chromosomes were grouped into the three or four masses and several spindles appeared. At the tetrad stage of meiosis Ⅱ, eytokinesis splitting abnormality occurred, and a variety of diad, triad, tetrad, pentad, hexad, as well as decury microspores were easily observed. As a consequence of abnormalities of the two meiotic stages, various microspores and the pollen were almost completely sterile. grains with different size were formed, and its pollen grains
基金Supported by National Natural Science Foundation of China,No.81300349 and No.81270532the Beijing Natural Science Foundation,No.7144216+3 种基金the Beijing Nova Program,No.Z131107000413016the Project of Science and Technology Activities of Preferred Overseas Personnel of Beijing(2014)the Project of Cultivation of High Level Medical Technical Personnel in the Health System of Beijing,No.2014-3-090 and No.2013-3-071Beijing Municipal Institute of public medical research development and reform pilot project,No.2016-2
文摘AIM To prepare a Gpm6a/Reelin^(GFPCreERT2) construct with a rapid and reliable strategy using a bacterial artificial chromosome(BAC). METHODS Gpm6 a and Reelin BACs were purified and transformed into SW102 E. coli by electroporation. The GFPCreE RT2 fragment was prepared from a shuttle vector and transformed into SW102 E. coli carrying a BAC. Homologous recombination was induced in SW102 E. coli. Recombinant clones were screened and confirmed by PCR and restriction enzyme digestion. Recombinant clones were transformed into SW102 E. coli to remove the kanamycin unit.RESULTS A complete BAC was successfully transformed into SW102 E. coli by electroporation because BAC purified from SW102 E. coli showed the same pattern as the original BAC with Bam H I digestion. The GFPCre ERT2 fragment was deemed to have been prepared successfully because we obtained the same size fragment as expected. Homologous recombination was induced, and GFPCre ERT2 was deemed to have been inserted into the correct site of the BAC because we found the band change was the same as the expected pattern after restriction enzyme digestion. The kanamycin unit was deemed to have been removed successfully because we obtained different sizes of bands that were consistent with the results expected by PCR with different primers. CONCLUSION The construct of Gpm6 a^(GFPCreERT2) or Reelin^(GFPCreERT2) was prepared successfully, which will establish a foundation for tracing the hepatic stellate cell lineage and studying its function.
基金Supported by the Hi-Tech Research and Development(863) Program of China(2001 AA222152,2003AA207100,and 2004AA222140)the National Natural Science Foundation of China and the Program for Changjiang Scholars and Innovative Research Team in University
文摘To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent parent Yangmal 5 to Isolate the resistance relative genes. A cDNA fragment specifically expressed in the resistant line was obtained and its full length was cloned by in silico cloning and RT-PCR. This gene encoded a deduced protein of 219 amino acids with a leucine-rich repeat （LRR） motif, often found In plant resistance genes, and was designated as Ta-LRR2. Ta-LRR2 had an increased expression level in the resistant line after Inoculation with Erysiphe graminis DC. f. sp. tritici Marchal. PCR analysis with different cytogenetlc stocks suggested that Ta-LRR2 was specifically associated with chromosome arms 6VS and 6AS. Linkage analysis further showed that Ta-LRR2 could be used as a resistance gene analog polymorphism marker of Pm21 for marker-assisted selection in germplasm enhancement and breeding practice. Moreover, how to Isolate Pm21 based on the Information obtained for Ta-LRR2 is discussed.
基金supported by the Zhejiang Natural Science Foundation(Y304446)the National 863 Program of China(2006AA10Z1E8)the Chinese Super Rice Breeding Program(200606).
文摘This study was undertaken to dissect quantitative trait loci （QTLs） controlling yield traits on the short arm of rice chromosome 6. A residual heterozygous line that carries a heterozygous segment extending from RM587 to RM19784 on the short arm of rice chromosome 6 was selected from an F7 population of the indica rice cross Zhenshan 97B/Milyang 46. An F2：3 population consisting of 221 lines was derived and grown in two trial sites. Six yield traits including number of panicles per plant, number of filled grains per panicle, total number of spikelets per panicle, spikelet fertility, 1 000-grain weight, and grain yield per plant were measured. An SSR marker linkage map was constructed and employed to determine QTLs for yield traits with Windows QTL Cartographer 2.5. QTLs were detected in the target interval for all the traits analyzed except NP, with phenotypic variance explained by a single QTL ranging between 6.3% and 35.2%. Most of the QTLs for yield components acted as additive QTLs, while the three QTLs for grain yield had dominance degrees of 1.65, 0.84, and -0.42, respectively. It was indicated that three or more QTLs for yield traits were located in the target region. The genetic action mode, the direction of the QTL effect, and the magnitude of the QTL effect varied among different QTLs for a given trait, and among QTLs for different traits that were located in the same interval.
