Fig. 2. A Phox2b enhancer that contains conserved Pbx-Hox and Prep/Meis
sites. (A) The mouse Phox2b locus highlighting (red box) a 376
nucleotide (nt) proximal enhancer (P2b_0.38). (B) Sequence alignment between
mouse, rat, human, zebrafish and fugu, showing high conservation. PH and P/M
binding elements are boxed in red and green, respectively. (C) Comparison
between PH and P/M sequences in Phox2b, Hoxb1 (ARE repeat 2)
(Popperl et al., 1995) and
Hoxb2 (Maconochie et al.,
1997) r4 enhancers. The Phox2b and Hoxb1 PH and
P/M core sequences are identical.