Determination of copy number for 5S rDNA and centromeric sequence RCS2 in rice by Fiber-FISH  

作　　者：Zongyun Li Siluo Huang Weiwei Jin Shunbin Ning Yunchun Song Lijia Li 

机构地区：[1]Wuhan Univ, Key Lab Minist Educ Plant Dev Biol, Wuhan 430072, Peoples R China

出　　处：《Chinese Science Bulletin》2002年第3期214-217,共4页

基　　金：This work was supported by the National Natural Science Foundation of China (Grant No. 39900083) ; the Research Fund of the Doctoral Program of Higher Education (Grant No. 207980112).

摘　　要：The copy number of 5S rDNA and centromerie sequence RCS2 was determined by extended DNA fiber based fluorescence in situ hybridization (Fiber-FISH) in rice (Oryza sativa ssp. indica cv. Guangluai No. 4) genome. In order to determine the copy number, it is necessary to know the basepair number that a given length DNA fiber contains under a microscope. Therefore, the length of two DNA frag-ments, in which the basepair number had been already known, was measured. The insert sequence of the tested BAC 38D17 was 136 kb and its extended DNA was 56.4 μm long, 2.41 kb/μm on average, while that of the tested BAC 44B4 was 144.5 kb in total and 55.7 μm long, 2.60 kb/μm on average under the microscope. They were very close to the theoretical value of B-DNA in the Watson-Crick DNA model, which is 2.97 kb/μm. According to the average value of basepair number per μm of the two samples mentioned above, that is, 2.51 kb/μm, it could be estimated that the copy number was about 686 for 5S rDNA and 286-1121 for theThe copy number of 5S rDNA and centromeric sequence RCS2 was determined by extended DNA fiber based fluorescence in situ hybridization (Fiber-FISH) in rice (Oryza sativa ssp. indica cv. Guangluai No. 4) genome. In order to determine the copy number, it is necessary to know the basepair number that a given length DNA fiber contains under a microscope. Therefore, the length of two DNA fragments, in which the basepair number had been already known, was measured. The insert sequence of the tested BAC 38D17 was 136 kb and its extended DNA was 56.4 μm long, 2.41 kb/μm on average, while that of the tested BAC 44B4 was 144.5 kb in total and 55.7 μm long, 2.60 kb/μm on average under the microscope. They were very close to the theoretical value of B-DNA in the Watson-Crick DNA model, which is 2.97 kb/μm. According to the average value of basepair number per μm of the two samples mentioned above, that is, 2.51 kb/μm, it could be estimated that the copy number was about 686 for 5S rDNA and 286–1121 for the centromere sequence RCS2.

关 键 词：centromeric DNA SEQUENCE 5S rDNA COPY number fiber based fluorescence in SITU HYBRIDIZATION (Fiber-FISH) rice. 

分 类 号：S511.01[农业科学—作物学]