...-Pbx-Prep ternary complex formation and regulation of the Phox2b enhancer activity in ventral r4. Moreover, the DV factor Nkx2.2 enhances Hox-mediated transactivation via a derepression mechanism. Finally, we show that induction of ectopic Phox2b -expressing visceral motoneurons in the chick hindbrain...

...., 1997a; Berthelsen et al., 1998a , 1999; Abu-Shaar et al., 1999 ), complex. Deletion of Prep1 homeodomain prevented ternary complex formation, as previously observed ( Berthelsen et al., 1998a ). We next investigated the Hoxb2 r4 enhancer (see Fig. 3 , for sequences and oligonucleotides). The PH...