Comprehensive analysis of mutant loxP and lox2272 sequences.

Sparse labeling of individual cells is an powerful approach in many fields of research. We aimed to develop a novel methodology based on the Cre-lox system to control sparseness level at the desired level. To accomplish our goal, we focused on the Brainbow system. The Brainbow system is a method of sparsely label the cells by using Cre recombinase. In the Brainbow system, the genetic circuit in which two pairs of lox sequences, lox2272 and loxP sequences, are inserted alternately is used. Cre cleaves one of the two sets of mutually exclusive pairs of lox sequences. We hypothesized that mutations in the lox sequence reduce the recognition efficiency by Cre. Thus, we comprehensively survey effects of mutation in lox sequences for recognition rate using NGS.