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 ord...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 the展开更多
The techniques of in situ hybridization (ISH) are widely adopted for analyzing the genetic make_up and RNA expression patterns of individual cells. There are four main criterions for evaluating this technique, includi...The techniques of in situ hybridization (ISH) are widely adopted for analyzing the genetic make_up and RNA expression patterns of individual cells. There are four main criterions for evaluating this technique, including detection sensitivity, resolution, capacity and specificity. This review focuses on a number of advances made over the last years in the fluorescence in situ hybridization (FISH). These advances can be catagorized into several branches as follows: (1) Multicolor_FISH (mFISH), including conventional mFISH, combinatorial FISH, ratio labelling FISH, multicolor chromosome painting and comparative genomic hybridization (CGH); (2) Extended DNA fiber_FISH (EDF_FISH), including quantitative DNA fiber mapping (QDFM), molecular combing (MC) and dynamic molecular combing (DMC); (3) In situ PCR_based FISH; (4) Bacterial (or yeast) artificial chromosome_FISH (BAC_FISH or YAC_FISH); (5) Tyramide signal amplification_FISH (TSA_FISH); (6) Polypeptide nucleic acid_FISH (PNA_FISH) and (7) padlock_FISH.展开更多
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).
文摘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 the
文摘The techniques of in situ hybridization (ISH) are widely adopted for analyzing the genetic make_up and RNA expression patterns of individual cells. There are four main criterions for evaluating this technique, including detection sensitivity, resolution, capacity and specificity. This review focuses on a number of advances made over the last years in the fluorescence in situ hybridization (FISH). These advances can be catagorized into several branches as follows: (1) Multicolor_FISH (mFISH), including conventional mFISH, combinatorial FISH, ratio labelling FISH, multicolor chromosome painting and comparative genomic hybridization (CGH); (2) Extended DNA fiber_FISH (EDF_FISH), including quantitative DNA fiber mapping (QDFM), molecular combing (MC) and dynamic molecular combing (DMC); (3) In situ PCR_based FISH; (4) Bacterial (or yeast) artificial chromosome_FISH (BAC_FISH or YAC_FISH); (5) Tyramide signal amplification_FISH (TSA_FISH); (6) Polypeptide nucleic acid_FISH (PNA_FISH) and (7) padlock_FISH.
