To unveil formation mechanism of key sequence boundaries of inland faulting basin and coal accumulation charac- teristics of coal seams in isochrohal stratigraphic framework, sequence stratigraphy, palaeogeographic re...To unveil formation mechanism of key sequence boundaries of inland faulting basin and coal accumulation charac- teristics of coal seams in isochrohal stratigraphic framework, sequence stratigraphy, palaeogeographic recovery and other methods were used to research the sequence stratigraphy and coal accumulation in the example of Banding Basn in the west margin of Yangtze Platform, and the authors advanced a coal accumulation model of Faulting basin on the basis of accommo- dation space changes in the background of palaeogeography of sequence framework. The results show that： normal lacustrine regression and forced lacustrine regression are the main driving forces for the formation of sequence boundaries of Faulting ba- sin; basement subsidence is the main source of accommodation space of Faulting basin; and subsidence disequilibrium is the main cause for the difference in generation rate of accommodation space of Faulting basin. Coal accumulation in Faulting basin is obviously controlled by accommodation space changes in sequence framework and basin evolution. As Faulting basin evolves into depression basin, both subsidence rate of basin basement and generation rate of accommodation space decrease vertically, it appears as a progradational reverse-graded sedimentary sequence, coal accumulation in secondary sequence framework intensifies first and then weakens, and coal accumulation at the middle stage of highstand system tract is the best. During steady rifting period, minable coal seams were mostly developed in initial lacustrine flooding surface of fourth-order sequence and at the middle-late period of highstand system tract, and coal accumulation center lay in palaeogeographic unit of delta plain with moderate available accommodation space. During shrinking period, minable coal seams gradually migrated to the maximum lacustrine flooding surface and coal accumulation center lay in palaeographical unit of lacustrine with large available accommodation space.展开更多
Motivation: It was found that high accuracy splicing-site recognitio n of rice (Oryza sativa L.) DNA sequence is especially difficult. We describe d a new method for the splicing-site recognition of rice DNA sequences...Motivation: It was found that high accuracy splicing-site recognitio n of rice (Oryza sativa L.) DNA sequence is especially difficult. We describe d a new method for the splicing-site recognition of rice DNA sequences. Method: Bas e d on the intron in eukaryotic organisms conforming to the principle of GT-AG,w e used support vector machines (SVM) to predict the splicing sites. By machine l earning,we built a model and used it to test the effect of the test data set of true and pseudo splicing sites. Results: The prediction accuracy we obtained wa s 87.53% at the true 5' end splicing site and 87.37% at the true 3' end splicing sites. The results suggested that the SVM approach could achieve higher accuracy than the previous approaches.展开更多
Brassinosteroids （BRs） are important hormones that regulate plant development and physiology. Substantial progresses have been made in BR-related studies, and especially an increasing number of new genes involved in...Brassinosteroids （BRs） are important hormones that regulate plant development and physiology. Substantial progresses have been made in BR-related studies, and especially an increasing number of new genes involved in BR biosynthesis have been identified. Here, we characterize a BR-related rice mutant, small grain 4 （sg4）, obtained from callus culture of japonica cultivar Nipponbare. This mutant showed multiple phenotypes such as dark green, rugose erect leaves and small round grains. It was higher than the wild type, different from the majority of BR- and gibberellin-related mutants. Genetic analysis showed that the mutant phenotypes are controlled by a single recessive locus. The gene was fine-mapped to a 90.7-kb interval with 1,100 F2 recessive individuals by means of map-basedcloning. Totally 11 open reading frames were found in this interval, only one of which was detected with an 8-bp in- sertion in the 5rUTR region by sequencing. Functional complementation test revealed that a DWARFll allele, LOC_OsO4g39430, is answer for the mutant phenotype of sg4. Tissue-specific response to BR and decreased expression levels of BR biosynthetic genes suggest that sg4 is a weak BR-deficient mutant. These results are beneficial to understanding the physiological action of sg4 in a more comprehensive way.展开更多
基金Supported by the State Key Scientific and Technological Program （2011 ZX05009-002） the National Natural Science Foundation （41002049） the Central University Basic Research Fund （2009QD12）
文摘To unveil formation mechanism of key sequence boundaries of inland faulting basin and coal accumulation charac- teristics of coal seams in isochrohal stratigraphic framework, sequence stratigraphy, palaeogeographic recovery and other methods were used to research the sequence stratigraphy and coal accumulation in the example of Banding Basn in the west margin of Yangtze Platform, and the authors advanced a coal accumulation model of Faulting basin on the basis of accommo- dation space changes in the background of palaeogeography of sequence framework. The results show that： normal lacustrine regression and forced lacustrine regression are the main driving forces for the formation of sequence boundaries of Faulting ba- sin; basement subsidence is the main source of accommodation space of Faulting basin; and subsidence disequilibrium is the main cause for the difference in generation rate of accommodation space of Faulting basin. Coal accumulation in Faulting basin is obviously controlled by accommodation space changes in sequence framework and basin evolution. As Faulting basin evolves into depression basin, both subsidence rate of basin basement and generation rate of accommodation space decrease vertically, it appears as a progradational reverse-graded sedimentary sequence, coal accumulation in secondary sequence framework intensifies first and then weakens, and coal accumulation at the middle stage of highstand system tract is the best. During steady rifting period, minable coal seams were mostly developed in initial lacustrine flooding surface of fourth-order sequence and at the middle-late period of highstand system tract, and coal accumulation center lay in palaeogeographic unit of delta plain with moderate available accommodation space. During shrinking period, minable coal seams gradually migrated to the maximum lacustrine flooding surface and coal accumulation center lay in palaeographical unit of lacustrine with large available accommodation space.
文摘Motivation: It was found that high accuracy splicing-site recognitio n of rice (Oryza sativa L.) DNA sequence is especially difficult. We describe d a new method for the splicing-site recognition of rice DNA sequences. Method: Bas e d on the intron in eukaryotic organisms conforming to the principle of GT-AG,w e used support vector machines (SVM) to predict the splicing sites. By machine l earning,we built a model and used it to test the effect of the test data set of true and pseudo splicing sites. Results: The prediction accuracy we obtained wa s 87.53% at the true 5' end splicing site and 87.37% at the true 3' end splicing sites. The results suggested that the SVM approach could achieve higher accuracy than the previous approaches.
基金supported by the National Natural Science Foundation of China(31201194,31171532,91335105and 31201183)
文摘Brassinosteroids （BRs） are important hormones that regulate plant development and physiology. Substantial progresses have been made in BR-related studies, and especially an increasing number of new genes involved in BR biosynthesis have been identified. Here, we characterize a BR-related rice mutant, small grain 4 （sg4）, obtained from callus culture of japonica cultivar Nipponbare. This mutant showed multiple phenotypes such as dark green, rugose erect leaves and small round grains. It was higher than the wild type, different from the majority of BR- and gibberellin-related mutants. Genetic analysis showed that the mutant phenotypes are controlled by a single recessive locus. The gene was fine-mapped to a 90.7-kb interval with 1,100 F2 recessive individuals by means of map-basedcloning. Totally 11 open reading frames were found in this interval, only one of which was detected with an 8-bp in- sertion in the 5rUTR region by sequencing. Functional complementation test revealed that a DWARFll allele, LOC_OsO4g39430, is answer for the mutant phenotype of sg4. Tissue-specific response to BR and decreased expression levels of BR biosynthetic genes suggest that sg4 is a weak BR-deficient mutant. These results are beneficial to understanding the physiological action of sg4 in a more comprehensive way.
