The proximal promoter of the murine Tff3 gene (lacking a goblet cell silencer inhibitor element) drives the expression of the full coding region of the murine Tmem207 gene. A genome walking assay revealed that the transgene inserted into a basic helix-loop-helix leucine zipper region of Mitf. Western blot analysis indicates that a lower level of Mitf protein is expressed in the brain than in wild-type mice. No line number is given, however this line was named 2 to distinguish between this line in which the transgene inserted in chromosome 6 and other lines that were created including line 1 that inserted in chromosome 2. (J:244533)