Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome a...Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome allows us to reveal the common features and the evolutionary rules of the gramineous genomes and accumulate the data for establishment of a common genetic system in the Poaceae. In this study, a rice gene Pib ( 10.3 kb), a map-based cloned gene, and RFLP markers linked with it are used as the tested probes to investigate their homology and physical location among the tested species. Southern blotting analysis showed that there were sequences homologous to Pib in maize genome. Further, Pib was localized onto the chromosomes of O. sativa ssp. indica cv. Guangluai 4, O. officinalis Wall ex Watt and the inbred line of Zea mays cv. Huangzao 4. The results of fluorescence in situ hybridization (FISH) and double-color FISH indicated that a synteny of Pib and RFLP markers linked with Pib existed among the genomes of the three tested species.展开更多
A set of 132 accessions of commonmillet, Panicum miliaceum L., from12 provinces of China were assessed for endosperm starch type （waxy or non-waxy） using I2-KI staining, amylose and amylopectin contents using the du...A set of 132 accessions of commonmillet, Panicum miliaceum L., from12 provinces of China were assessed for endosperm starch type （waxy or non-waxy） using I2-KI staining, amylose and amylopectin contents using the dual-wavelength colorimetric method, and genotype of Waxygenes conditioning amylose content by gene sequencing. Endosperm starch content varied from 57.69% to 74.70%, while the amylose and amylopectin contents of the starch ranged from 0 to 23.29% and from 41.99% to 70.24%, respectively. Sequencing two Wx genes, including Wx-L （intron 5-exon 7 and intron 8–9） andWx-S （exon 9–intron 10） revealed several polymorphisms （S0, S？15, LC, LF, LY）. Marker M5-R11 linking to the Wx-S gene may be used to discriminate waxy common millet accessions from non-waxy ones. Among the 132 accessions, 68 with the S？15 allele had waxy endosperm starch with the amylose content range 0–2.58% and 64 accessions with the S0 allele had non-waxy endosperm starch with amylose content range 3.94%–23.29%. Five genotypes including So15/LF （45% of the accessions）, S0/LF （25%）, S0/LY （12%）, S0/LC （11%）, and S？15/LY （7%） were identified. Six new SNPs were detected at the Wx-L locus. These results will facilitate common millet breeding, especially of cultivars free of amylose.展开更多
Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chro...Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chromosomes together until the metaphase I to anaphase I transition, is critical for proper chromosome segregation. Recent studies have suggested that the SPO 11 proteins have conserved functions in a number of organisms in generating sites of double-stranded DNA breaks （DSBs） that are thought to be the starting points of homologous recombination. Processing of these sites of DSBs requires the function of RecA homologs, such as RAD5 1, DMC 1, and others, as suggested by mutant studies; thus the failure to repair these meiotic DSBs results in abnormal chromosomal alternations, leading to disrupted meiosis. Recent discoveries on the functions of these RecA homologs have improved the understanding of the mechanisms underlying meiotic homologous recombination.展开更多
Dinoflagellate is one of the primitive eukaryotes, whose nucleus may represent one of the transition stages from prokaryotic nucleoid to typical eukaryotic nucleus. Using selective extraction together with embeddment ...Dinoflagellate is one of the primitive eukaryotes, whose nucleus may represent one of the transition stages from prokaryotic nucleoid to typical eukaryotic nucleus. Using selective extraction together with embeddment - free section and whole mount electron microscopy, a delicate nuclear matrix filament network was shown, for the first time, in dinoflagellate Crypthecodinium cohnii nucleus. Chromosome residues are connected with nuclear matrix filaments to form a complete network spreading over the nucleus. Moreover, we demonstrated that the dinoflagellate chromosome retains a protein scaffold after the depletion of DNA and soluble proteins. This scaffold preserves the characteristic morphology of the chromosome. Two dimensional elec-trophoreses indicated that the nuclear matrix and chromosome scaffold are mainly composed of acidic proteins. Our results demonstrated that a framework similar to the nuclear matrix and chromosome scaffold in mammalian cells appears in this primitive eukaryote,suggesting that these structures may have been originated from the early stages of eukaryote evolution.展开更多
A green and simplified room-temperature procedure was reported for the synthesis of carbon-carbon double bonds by Knoevenagel condensation of various aldehydes with malononitrile and ethyl cyanoacetate in the presence...A green and simplified room-temperature procedure was reported for the synthesis of carbon-carbon double bonds by Knoevenagel condensation of various aldehydes with malononitrile and ethyl cyanoacetate in the presence of catalytic amount of ZrOCl2·8H2O in aqueous media.展开更多
In the present study,we explored the correlation between 5-hydroxymethylfurfural(5-HMF)and color of Rehmanniae Radix(RR)and Rehmanniae Radix Praeparata(RRP).The color was observed by human eyes under sunlight.The chro...In the present study,we explored the correlation between 5-hydroxymethylfurfural(5-HMF)and color of Rehmanniae Radix(RR)and Rehmanniae Radix Praeparata(RRP).The color was observed by human eyes under sunlight.The chromatic value and color difference were detected by a colorimeter.The water content was determined by an oven-drying method.The 5-HMF content was determined by an HPLC method.The correlation between the 5-HMF content and the color was analyzed by bivariate correlation analysis.The results showed that the color was greyish-brown and dark brown for RR,and it was black for RRP.The deepening color of RRP was reflected in the decrease of L^*,a^*and b^*values.The water content was in accord with the requirement of Chinese Pharmacopoeia.The 5-HMF contents of RR and RRP were 0.9711–25.71μg/g and 213.4–4010μg/g,respectively.The average 5-HMF contents of RR and RRP were 8.059μg/g and 1433μg/g,respectively.The 5-HMF content in RRP was higher than that in RR.The correlations between 5-HMF content and L^*,a^*and b^*values were significant.The color of RRP was deeper than that of RR.The 5-HMF content of RRP was higher than 0.02%,while it was less than 0.02%of RR,which could be used as a marker component for judging RR and RRP.展开更多
文摘Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome allows us to reveal the common features and the evolutionary rules of the gramineous genomes and accumulate the data for establishment of a common genetic system in the Poaceae. In this study, a rice gene Pib ( 10.3 kb), a map-based cloned gene, and RFLP markers linked with it are used as the tested probes to investigate their homology and physical location among the tested species. Southern blotting analysis showed that there were sequences homologous to Pib in maize genome. Further, Pib was localized onto the chromosomes of O. sativa ssp. indica cv. Guangluai 4, O. officinalis Wall ex Watt and the inbred line of Zea mays cv. Huangzao 4. The results of fluorescence in situ hybridization (FISH) and double-color FISH indicated that a synteny of Pib and RFLP markers linked with Pib existed among the genomes of the three tested species.
基金supported by the National Natural Science Foundation of China(31271791)Research Project supported by Shanxi Scholarship Council of China(2016-066)+4 种基金the Subject Construction Project of Anhui Academy of Agricultural Sciences(16A0102)China Agriculture Research System(CARS-06-13.5-A16)the Key Research and Development Program(General Project)(Agriculture)of Shanxi Province of China(201603D221003-5)the Special Program of Crop Germplasm Resources Protection and Utilization of Ministry of Agriculture of the People's Republic of China(2017NWB036-21)the Subplatform Project of National Proso Millet Germplasm Resources of China(NICGR2017-027)
文摘A set of 132 accessions of commonmillet, Panicum miliaceum L., from12 provinces of China were assessed for endosperm starch type （waxy or non-waxy） using I2-KI staining, amylose and amylopectin contents using the dual-wavelength colorimetric method, and genotype of Waxygenes conditioning amylose content by gene sequencing. Endosperm starch content varied from 57.69% to 74.70%, while the amylose and amylopectin contents of the starch ranged from 0 to 23.29% and from 41.99% to 70.24%, respectively. Sequencing two Wx genes, including Wx-L （intron 5-exon 7 and intron 8–9） andWx-S （exon 9–intron 10） revealed several polymorphisms （S0, S？15, LC, LF, LY）. Marker M5-R11 linking to the Wx-S gene may be used to discriminate waxy common millet accessions from non-waxy ones. Among the 132 accessions, 68 with the S？15 allele had waxy endosperm starch with the amylose content range 0–2.58% and 64 accessions with the S0 allele had non-waxy endosperm starch with amylose content range 3.94%–23.29%. Five genotypes including So15/LF （45% of the accessions）, S0/LF （25%）, S0/LY （12%）, S0/LC （11%）, and S？15/LY （7%） were identified. Six new SNPs were detected at the Wx-L locus. These results will facilitate common millet breeding, especially of cultivars free of amylose.
基金The authors thank Alexandra Surcel and Carey L Hendrix Lord for helpful comments on this manuscript.The work in our laboratory is supported by grants from the National Science Foundation(IBN-0077832,MCB-9896340,MCB-0092075)the National Institutes of Health(R0 1 GM63871)+3 种基金the US Department of Agriculture(2001-35301-10570 and 2003-35301-13313)Wuxing L was partially supported by the Intercollege Graduate Degree Program in Plant PhysiologyHong M gratefully acknowledges the support of the John Simon Guggenheim Foundationthe National Institutes of Health(F33 GM72245-1).
文摘Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chromosomes together until the metaphase I to anaphase I transition, is critical for proper chromosome segregation. Recent studies have suggested that the SPO 11 proteins have conserved functions in a number of organisms in generating sites of double-stranded DNA breaks （DSBs） that are thought to be the starting points of homologous recombination. Processing of these sites of DSBs requires the function of RecA homologs, such as RAD5 1, DMC 1, and others, as suggested by mutant studies; thus the failure to repair these meiotic DSBs results in abnormal chromosomal alternations, leading to disrupted meiosis. Recent discoveries on the functions of these RecA homologs have improved the understanding of the mechanisms underlying meiotic homologous recombination.
文摘Dinoflagellate is one of the primitive eukaryotes, whose nucleus may represent one of the transition stages from prokaryotic nucleoid to typical eukaryotic nucleus. Using selective extraction together with embeddment - free section and whole mount electron microscopy, a delicate nuclear matrix filament network was shown, for the first time, in dinoflagellate Crypthecodinium cohnii nucleus. Chromosome residues are connected with nuclear matrix filaments to form a complete network spreading over the nucleus. Moreover, we demonstrated that the dinoflagellate chromosome retains a protein scaffold after the depletion of DNA and soluble proteins. This scaffold preserves the characteristic morphology of the chromosome. Two dimensional elec-trophoreses indicated that the nuclear matrix and chromosome scaffold are mainly composed of acidic proteins. Our results demonstrated that a framework similar to the nuclear matrix and chromosome scaffold in mammalian cells appears in this primitive eukaryote,suggesting that these structures may have been originated from the early stages of eukaryote evolution.
文摘A green and simplified room-temperature procedure was reported for the synthesis of carbon-carbon double bonds by Knoevenagel condensation of various aldehydes with malononitrile and ethyl cyanoacetate in the presence of catalytic amount of ZrOCl2·8H2O in aqueous media.
基金China Agriculture Research System(Grant No.CARS-21).
文摘In the present study,we explored the correlation between 5-hydroxymethylfurfural(5-HMF)and color of Rehmanniae Radix(RR)and Rehmanniae Radix Praeparata(RRP).The color was observed by human eyes under sunlight.The chromatic value and color difference were detected by a colorimeter.The water content was determined by an oven-drying method.The 5-HMF content was determined by an HPLC method.The correlation between the 5-HMF content and the color was analyzed by bivariate correlation analysis.The results showed that the color was greyish-brown and dark brown for RR,and it was black for RRP.The deepening color of RRP was reflected in the decrease of L^*,a^*and b^*values.The water content was in accord with the requirement of Chinese Pharmacopoeia.The 5-HMF contents of RR and RRP were 0.9711–25.71μg/g and 213.4–4010μg/g,respectively.The average 5-HMF contents of RR and RRP were 8.059μg/g and 1433μg/g,respectively.The 5-HMF content in RRP was higher than that in RR.The correlations between 5-HMF content and L^*,a^*and b^*values were significant.The color of RRP was deeper than that of RR.The 5-HMF content of RRP was higher than 0.02%,while it was less than 0.02%of RR,which could be used as a marker component for judging RR and RRP.
