Fig. 3.

Ntl binds clusters of T-box sites near tbx6 and deltaD in vivo. (A,C) The genomic loci of tbx6 (A) and dld (C) are schematized with sequence identity between the orthologous zebrafish and Fugu sequences plotted above the gene schematics using VISTA (Mayor et al., 2000; Frazer et al., 2004) (the Fugu tbx6 ortholog has not yet been sequenced). Matches to the Spt and/or Ntl binding site models with a PATSER P-value ≤0.001 are depicted as hatch marks below the gene schematics, with all T-box sites shown first, followed by those that belong to a cluster of 5 and 7 sites within 500 bp of one another. Previously identified dld neural regulatory elements HI and HII (Hans and Campos-Ortega, 2002) are shown in grey in C. (B,D) Chromatin immunoprecipitation was carried out using an antibody against Ntl. Fold enrichment in the Ntl-immunoprecipitated samples is shown. Error bars are not assigned to the Ntl-ChIP data since it represents the median of ratios.