POSITIVE AND NEGATIVE DNA-SEQUENCE ELEMENTS ARE REQUIRED TO ESTABLISHTHE PATTERN OF PAX3 EXPRESSION

The transcription start site and DNA sequence elements required for th e induction of Pax3 expression in differentiating P19 embryonal carcin oma cells have been localized. These elements consist of a promoter an d additional elements located within 1.6 kbp 5' to the transcription s tart site. Sequence elements within this 1.6 kbp region are also suffi cient to mediate the induction and dorsal restriction of Pax3 in the n eural tube and somites of transgenic mice throughout the hindbrain and trunk. Additional elements required for expression anterior to the hi ndbrain and in migrating myoblasts are located within 14 kbp 5' to the transcription start site. This region also contains element(s) that r epress Pax3 expression in the ventral body wall mesoderm of the tail b ud.