We mapped and analyzed the microsatellites throughout 284295605 base pairs ofthe unambiguously assembled sequence scaffolds along 19 chromosomes of the haploid poplargenome.Totally,we found 150985 SSRs with repeat uni...We mapped and analyzed the microsatellites throughout 284295605 base pairs ofthe unambiguously assembled sequence scaffolds along 19 chromosomes of the haploid poplargenome.Totally,we found 150985 SSRs with repeat unit lengths between 2 and 5 bp.The establishedmicrosatellite physical map demonstrated tr at SSRs were distributed relatively evenly across thegenome of Populus.On average,These SSRs occurred every 1883 bp within the poplar genome and the SSRdensities in intergenic regions,introns,exons and UTRs were 85.4%,10.7%,2.7% and1.2%,respectively.We took di-,tri-,tetra-and pentamers as the four classes of repeat units and foundthat the density of each class of SSRs decreased with the repeat unit lengths except for thetetranucleotide repeats.It was noteworthy that the length diversification of microsatellitesequences was negatively correlated with their repeat unit length and the SSRs with shorter repeatunits gained repeats faster than the SSRs with longer repeat units.We also found that the GC contentof poplar sequence significantly correlated with densities of SSRs with uneven repeat unit lengths(tri-and penta-),but had no significant correlation with densities of SSRs with even repeat unitlengths (di-and tetra-).In poplar genome,there were evidences that the occurrence of differentmicrosatellites was under selection and the GC content in SSR sequences was found to significantlyrelate to the functional importance of microsatellites.展开更多
Photoperiod-sensitive genie male sterile (PSGMS) rice is a very useful germplasm for hybrid rice development. It was first found as a spontaneous mutant in a japonic a cultivar 'Nongken 58' . pms3 on chromosom...Photoperiod-sensitive genie male sterile (PSGMS) rice is a very useful germplasm for hybrid rice development. It was first found as a spontaneous mutant in a japonic a cultivar 'Nongken 58' . pms3 on chromosome 12 was determined to be the locus where the original PSGMS mutation occurred, changing the normal cultivar Nongken 58 to PSGMS Nongken 58S. Large amounts of RAPD and AFLP analyses were also conducted for the fine mapping of the pms3 genomic region, which resulted in 4 molecular markers linked to pms3. Although these markers somewhat increased the marker density of this region, the pms3 locus is still located in a marker-sparse region.展开更多
To determine differential expression of genie male sterility A/B lines in Chinese cabbage-pak-choi (Brassica campestris ssp. chinensis Makino var. communis Tsen et Lee), we used the RNA fingerprinting technique, cDNA-...To determine differential expression of genie male sterility A/B lines in Chinese cabbage-pak-choi (Brassica campestris ssp. chinensis Makino var. communis Tsen et Lee), we used the RNA fingerprinting technique, cDNA-AFLP analysis, in different developmental stages and different tissues. While no obvious differential expressions were observed in rosette leaves, florescence leaves, and scapes, some differential expressions were found in alabstrums of A/B lines and among leaves, scapes and alabstrums. We analyzed the al-abstrums collected in different developmental stages with 10 primer combinations. We got a unique band between middle size alabstrums and large alabstrums in B line in one of the ten pair primers, and in another one pair, one band reflecting a higher gene-expression level in A line than that in B line was obtained. No unique bands were found with the other primer combinations. The bands reflecting different gene-expression level were confirmed by Northern hybridization. The results indicated that cDNA-AFLP was a suitable tool for studying differential expression of genie male sterility in plants. SDS-polyacrylamide gel electrophoresis patterns of soluble proteins further verified the difference in A/B lines.展开更多
The fertile and sterile young panicle representational populations were constructed by bulked sampling method using young panicles in the photo-period sensitive stage of fertility transformation.Two populations were a...The fertile and sterile young panicle representational populations were constructed by bulked sampling method using young panicles in the photo-period sensitive stage of fertility transformation.Two populations were analyzed using cDNA-RAPD. The results showed that: ( ⅰ ) bulked sampling method can be employed to analyze differentially expressed genes using cDNA-RAPD, taking an advantage in avoiding false positive caused by conventional sampling method. (ⅱ) Among 150 random primers used, 83 primers amplified the same banding patterns, and 34 primers amplified the same banding pattern but different staining of intensity on gel. ( ⅲ ) 33 primers amplified differential cDNA bands between fertile and sterile cDNA populations, and the ratio of polymorphism was 22%. It is concluded that there may exist a lot of genes relating to sterility, which makes the differentially expressed cDNA fragments complicated.展开更多
The optimum condition of three commonly used functions in the Genie 2000 γ spectra analysis software have been studied in the 121-1408 keV energy range. The three functions are applied for fitting the full-energy pea...The optimum condition of three commonly used functions in the Genie 2000 γ spectra analysis software have been studied in the 121-1408 keV energy range. The three functions are applied for fitting the full-energy peak efficiency of the HPGe gamma-ray detector. A detailed procedure to obtain the optimum condition is described. The HPGe detector is calibrated at 11 cm by three radioactive sources of point form （^152Eu, ^137Cs, ^60Co） providing 11 energy peaks. After data processing, results shows that the three functions used in the Genie 2000 gamma spectra analysis software fit best at orders 3-5. Lastly the standard radioactive source 133Ba is chosen to validate the results. Differences between the standard activity of 133Ba and the result obtained from the fitting functions are below 1.5%. Therefore the optimum orders of the three functions used in the Genie 2000 3, spectra analysis software are 3-5 with the 11 energy peaks.展开更多
基金Supported by Program for New Century Excellent Talents in University (Grant No. NCET-04-0516)Fok Ying Tung Education Foundation, and the National Natural Science Foundation of China (Grant No. 30200224)
文摘We mapped and analyzed the microsatellites throughout 284295605 base pairs ofthe unambiguously assembled sequence scaffolds along 19 chromosomes of the haploid poplargenome.Totally,we found 150985 SSRs with repeat unit lengths between 2 and 5 bp.The establishedmicrosatellite physical map demonstrated tr at SSRs were distributed relatively evenly across thegenome of Populus.On average,These SSRs occurred every 1883 bp within the poplar genome and the SSRdensities in intergenic regions,introns,exons and UTRs were 85.4%,10.7%,2.7% and1.2%,respectively.We took di-,tri-,tetra-and pentamers as the four classes of repeat units and foundthat the density of each class of SSRs decreased with the repeat unit lengths except for thetetranucleotide repeats.It was noteworthy that the length diversification of microsatellitesequences was negatively correlated with their repeat unit length and the SSRs with shorter repeatunits gained repeats faster than the SSRs with longer repeat units.We also found that the GC contentof poplar sequence significantly correlated with densities of SSRs with uneven repeat unit lengths(tri-and penta-),but had no significant correlation with densities of SSRs with even repeat unitlengths (di-and tetra-).In poplar genome,there were evidences that the occurrence of differentmicrosatellites was under selection and the GC content in SSR sequences was found to significantlyrelate to the functional importance of microsatellites.
基金Project supported by the National Program of High Technology Development of China and the Rockefeller Foundation.
文摘Photoperiod-sensitive genie male sterile (PSGMS) rice is a very useful germplasm for hybrid rice development. It was first found as a spontaneous mutant in a japonic a cultivar 'Nongken 58' . pms3 on chromosome 12 was determined to be the locus where the original PSGMS mutation occurred, changing the normal cultivar Nongken 58 to PSGMS Nongken 58S. Large amounts of RAPD and AFLP analyses were also conducted for the fine mapping of the pms3 genomic region, which resulted in 4 molecular markers linked to pms3. Although these markers somewhat increased the marker density of this region, the pms3 locus is still located in a marker-sparse region.
基金supported by the National Natural Science Foundation of China(39670512)
文摘To determine differential expression of genie male sterility A/B lines in Chinese cabbage-pak-choi (Brassica campestris ssp. chinensis Makino var. communis Tsen et Lee), we used the RNA fingerprinting technique, cDNA-AFLP analysis, in different developmental stages and different tissues. While no obvious differential expressions were observed in rosette leaves, florescence leaves, and scapes, some differential expressions were found in alabstrums of A/B lines and among leaves, scapes and alabstrums. We analyzed the al-abstrums collected in different developmental stages with 10 primer combinations. We got a unique band between middle size alabstrums and large alabstrums in B line in one of the ten pair primers, and in another one pair, one band reflecting a higher gene-expression level in A line than that in B line was obtained. No unique bands were found with the other primer combinations. The bands reflecting different gene-expression level were confirmed by Northern hybridization. The results indicated that cDNA-AFLP was a suitable tool for studying differential expression of genie male sterility in plants. SDS-polyacrylamide gel electrophoresis patterns of soluble proteins further verified the difference in A/B lines.
文摘The fertile and sterile young panicle representational populations were constructed by bulked sampling method using young panicles in the photo-period sensitive stage of fertility transformation.Two populations were analyzed using cDNA-RAPD. The results showed that: ( ⅰ ) bulked sampling method can be employed to analyze differentially expressed genes using cDNA-RAPD, taking an advantage in avoiding false positive caused by conventional sampling method. (ⅱ) Among 150 random primers used, 83 primers amplified the same banding patterns, and 34 primers amplified the same banding pattern but different staining of intensity on gel. ( ⅲ ) 33 primers amplified differential cDNA bands between fertile and sterile cDNA populations, and the ratio of polymorphism was 22%. It is concluded that there may exist a lot of genes relating to sterility, which makes the differentially expressed cDNA fragments complicated.
文摘The optimum condition of three commonly used functions in the Genie 2000 γ spectra analysis software have been studied in the 121-1408 keV energy range. The three functions are applied for fitting the full-energy peak efficiency of the HPGe gamma-ray detector. A detailed procedure to obtain the optimum condition is described. The HPGe detector is calibrated at 11 cm by three radioactive sources of point form （^152Eu, ^137Cs, ^60Co） providing 11 energy peaks. After data processing, results shows that the three functions used in the Genie 2000 gamma spectra analysis software fit best at orders 3-5. Lastly the standard radioactive source 133Ba is chosen to validate the results. Differences between the standard activity of 133Ba and the result obtained from the fitting functions are below 1.5%. Therefore the optimum orders of the three functions used in the Genie 2000 3, spectra analysis software are 3-5 with the 11 energy peaks.
