Fig. Ext. 7

a,b, Genome coverage plots of snATACseq signal in 3 dpf zebrafish gill progenitors versus other CNCCs (top) and human outer-ear, epiglottis, and nose libraries (mesenchymal and cartilage cell types only) (bottom). Grey bars indicate regions of sequence conservation. The weak yet selective signals of some conserved peaks in human samples may reflect partial retention of accessibility from earlier usage of enhancers in outer ear (a) and epiglottis (b) development. c,d, In situ hybridization for mouse homologs of genes linked to sequence-conserved gill developmental DARs. Staining of sagittal sections of E14.5 mouse embryos are reproduced from GenePaint19. Magnified boxed regions on right highlight expression associated with the outer-ear canal with red dashed lines outlining the ear canal lumen (c), and larynx with red dashed lines outlining the epiglottis (d). Scale bars, 500 µm.