Transformation as a tool for genetic fine mapping of closely located mutations in Thermus thermophilus

Abstract Recombination indexes were measured among six Trp⁻ mutants of Thermus thermophilus HB27 by reciprocal transformation among the mutants. Based on the index values, the order and distance of four closely located mutation sites were predicted. Cloning and sequence analysis of the mutants revealed that the order and distance among the mutation sites predicted from the index values were correct. A similar relationship between the index value and real distance was also obtained for two Pro⁻ mutants. These results suggest that transformation can be used as a tool for genetic fine mapping in T. thermophilus .