Genetic Analysis of a Mutant Mouse with White Coat Color Newly Discovered in C57BL/6JJic Mice and The Application on Bioresources

摘要

For more efficient transgenic mouse production, we have attempted to establish ES cell lines from various strains of mice. Recently, we discovered a mutant mouse (B6W) with white coat color and black eyes in C57BL/6JJic (B6) mice. In this study, we performed genetic analysis on the mutated gene in B6W mice. In addition, we have established ES cell lines from the mutant mice to use as a bioresource for transgenic technology. To examine the inheritance of the mutated gene, F1 mice were obtained by in vitro fertilization between a mutant male and albino NOD females. All Fl mice had a white coat color, suggesting that the mutation occurred on the tyrosinase gene. Further comparative sequence analysis on the tryrosinase coding regions between B6W and B6 mice revealed that this mutation occurred in the external part of the gene but not in the coding region. Sixteen ES cell lines were established from 41 blastocysts derived from 3 pregnant mice. In karyotype analysis, 10 cell lines were found to be normal. We are now examining the ability of these ES cell lines to generate chimeric mice and their germ line transmission. In conditional knockout mouse production, 129 ES cell lines have been used. In detailed studies, the KO mice must often be backcrossed with C57BL/6 mice. In this respect, the use of B6W ES cell lines enables us to produce KO mice more rapidly and at lower cost.