N-ethyl-N-nitrosourea(ENU)mutagenesis in mice can be used to study gene function in vivo and to establish genetic mouse models of human disease.In this study,a white spotted mouse(named Kit W-1Bao)was obtained by ENU-...N-ethyl-N-nitrosourea(ENU)mutagenesis in mice can be used to study gene function in vivo and to establish genetic mouse models of human disease.In this study,a white spotted mouse(named Kit W-1Bao)was obtained by ENU-induced mutagenesis.Inheritance testing showed a single-gene dominant mutation and lethality in the Kit W-1Bao homozygous mice.The mutation was mapped to Chromosome 5 between markers D5Mit356 and D5Mit308.The region contains the Kit gene,whose mutations are known to lead to pigmentation defects in mice.Sequence analysis of the Kit cDNA from Kit W-1Bao heterozygotes revealed an A to T missense mutation resulting in an amino acid substitution of Asp(D)by Val(V)at amino acid position 849 within a highly conserved tyrosine kinase domain.The combined phenotype displayed by the Kit W-1Bao heterozygous and homozygous mutant mice demonstrates the critical function of the highly conserved aspartic acid residue at position 849 in the Kit gene product.展开更多
Phenotype-driven is the name for an ap-proach used to study gene functions through mutagenesis, location and cloning of the mutant gene. In this study, 150 male C57BL/6J(B6) mice were treated with ENU and repro-duced ...Phenotype-driven is the name for an ap-proach used to study gene functions through mutagenesis, location and cloning of the mutant gene. In this study, 150 male C57BL/6J(B6) mice were treated with ENU and repro-duced a total offspring of 3860. Of these descendants, 210 exhibited mutation phenotypes by screening, and more than 10 of them are hereditable. Four kinds of mutant mice, named Wbct, W-1Bao, W-2Bao, and W-3Bao, showed dominant hereditary white spot mutation with partial albinism on their belly, distal limbs and tail terminal. To map these mutant genes, 39 microsatellites, equally distributed on the mouse genome and with difference between B6 and DBA/2J (D2), were selected to scan the genome after discrimination of the white spots in the F2 mice [(B6×D2)×D2]. It is found that, the log odds score (LODS) between W-1Bao and D5Mit168 is 0.56, and the LODS of W-1Bao and D5Mit352 is 4.47. With the gradual application of microsatellites D5Mit290, D5Mit312, D5Mit308 and D5Mit356 that are close to the mutant gene, and the number of F2 mice going up to 537, the mutant W-1Bao is located between D5Mit356 and D5Mit308 on chro-mosome 5, about 42.19 cM from the centromere. In the same way, W-2Bao and W-3Bao are mapped nearby W-1Bao, and Wbct is located on chromosome 1, about 41.6 cM from the centro-mere. After searching for the mouse genome database (MGD) and performing a one-by-one study of all genes located on chromosome subregion, it is believed that the kit gene is an excellent candidate for the white spot mutations of W-1Bao, W-2Bao and W-3Bao.展开更多
基金supported by the National Natural Science Foundation of China(NO.30670231)Public Service Project of Lab Animal Science(NO.2008F80005)SRF for ROCS,SEM
文摘N-ethyl-N-nitrosourea(ENU)mutagenesis in mice can be used to study gene function in vivo and to establish genetic mouse models of human disease.In this study,a white spotted mouse(named Kit W-1Bao)was obtained by ENU-induced mutagenesis.Inheritance testing showed a single-gene dominant mutation and lethality in the Kit W-1Bao homozygous mice.The mutation was mapped to Chromosome 5 between markers D5Mit356 and D5Mit308.The region contains the Kit gene,whose mutations are known to lead to pigmentation defects in mice.Sequence analysis of the Kit cDNA from Kit W-1Bao heterozygotes revealed an A to T missense mutation resulting in an amino acid substitution of Asp(D)by Val(V)at amino acid position 849 within a highly conserved tyrosine kinase domain.The combined phenotype displayed by the Kit W-1Bao heterozygous and homozygous mutant mice demonstrates the critical function of the highly conserved aspartic acid residue at position 849 in the Kit gene product.
文摘Phenotype-driven is the name for an ap-proach used to study gene functions through mutagenesis, location and cloning of the mutant gene. In this study, 150 male C57BL/6J(B6) mice were treated with ENU and repro-duced a total offspring of 3860. Of these descendants, 210 exhibited mutation phenotypes by screening, and more than 10 of them are hereditable. Four kinds of mutant mice, named Wbct, W-1Bao, W-2Bao, and W-3Bao, showed dominant hereditary white spot mutation with partial albinism on their belly, distal limbs and tail terminal. To map these mutant genes, 39 microsatellites, equally distributed on the mouse genome and with difference between B6 and DBA/2J (D2), were selected to scan the genome after discrimination of the white spots in the F2 mice [(B6×D2)×D2]. It is found that, the log odds score (LODS) between W-1Bao and D5Mit168 is 0.56, and the LODS of W-1Bao and D5Mit352 is 4.47. With the gradual application of microsatellites D5Mit290, D5Mit312, D5Mit308 and D5Mit356 that are close to the mutant gene, and the number of F2 mice going up to 537, the mutant W-1Bao is located between D5Mit356 and D5Mit308 on chro-mosome 5, about 42.19 cM from the centromere. In the same way, W-2Bao and W-3Bao are mapped nearby W-1Bao, and Wbct is located on chromosome 1, about 41.6 cM from the centro-mere. After searching for the mouse genome database (MGD) and performing a one-by-one study of all genes located on chromosome subregion, it is believed that the kit gene is an excellent candidate for the white spot mutations of W-1Bao, W-2Bao and W-3Bao.
