The relaxation property of both Eigen model and Crow-Kimura model with a single peak fitness landscape is studied from phase transition point of view. We first analyze the eigenvalue spectra of the replication mutatio...The relaxation property of both Eigen model and Crow-Kimura model with a single peak fitness landscape is studied from phase transition point of view. We first analyze the eigenvalue spectra of the replication mutation matrices. For sufficiently long sequences, the almost crossing point between the largest and seeond-largest eigenvalues locates the error threshold at which critical slowing down behavior appears. We calculate the critical exponent in the limit of infinite sequence lengths and compare it with the result from numerical curve fittings at sufficiently long sequences. We find that for both models the relaxation time diverges with exponent 1 at the error （mutation） threshold point. Results obtained from both methods agree quite well. From the unlimited correlation length feature, the first order phase transition is further confirmed. Finally with linear stability theory, we show that the two model systems are stable for all ranges of mutation rate. The Igigen model is asymptotically stable in terms of mutant classes, and the Crow-Kimura model is completely stable.展开更多
Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1...Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1,2 and 7 bp)and 2 deletions(1 and 2 bp)in the hepatocyte nuclear factor(HNF)-4α,glucokinase and HNF-1α genes were tested.During nested PCR,amplified fragments were labeled with three fluorescent dyes.PCR products were visualized with an ABI-377 fluorescence sequencer using 5% glycerol or 10% sucrose in nondenaturing gel conditions.Results Twenty-five of 27 variants(93%)could be detected by combining 5% glycerol and 10% sucrosegel matrix conditions.Twenty-two of 27(82%)and 18 of 27(67%)variants were identified using 5%glycerol and 10% sucrose conditions,respectively.Conclusion This fluorescence-based PCR single strand conformation polymorphism technique represents a simple,non-hazardous,time-saving and sensitive method for high throughput mutation detection.展开更多
基金Supported in part by the National natural Science Foundation of China under Grant No.10675170Major State Basic Research Developing Program under Gant No.2007CB815003
文摘The relaxation property of both Eigen model and Crow-Kimura model with a single peak fitness landscape is studied from phase transition point of view. We first analyze the eigenvalue spectra of the replication mutation matrices. For sufficiently long sequences, the almost crossing point between the largest and seeond-largest eigenvalues locates the error threshold at which critical slowing down behavior appears. We calculate the critical exponent in the limit of infinite sequence lengths and compare it with the result from numerical curve fittings at sufficiently long sequences. We find that for both models the relaxation time diverges with exponent 1 at the error （mutation） threshold point. Results obtained from both methods agree quite well. From the unlimited correlation length feature, the first order phase transition is further confirmed. Finally with linear stability theory, we show that the two model systems are stable for all ranges of mutation rate. The Igigen model is asymptotically stable in terms of mutant classes, and the Crow-Kimura model is completely stable.
文摘Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1,2 and 7 bp)and 2 deletions(1 and 2 bp)in the hepatocyte nuclear factor(HNF)-4α,glucokinase and HNF-1α genes were tested.During nested PCR,amplified fragments were labeled with three fluorescent dyes.PCR products were visualized with an ABI-377 fluorescence sequencer using 5% glycerol or 10% sucrose in nondenaturing gel conditions.Results Twenty-five of 27 variants(93%)could be detected by combining 5% glycerol and 10% sucrosegel matrix conditions.Twenty-two of 27(82%)and 18 of 27(67%)variants were identified using 5%glycerol and 10% sucrose conditions,respectively.Conclusion This fluorescence-based PCR single strand conformation polymorphism technique represents a simple,non-hazardous,time-saving and sensitive method for high throughput mutation detection.
