GFP expression in stable transgenic zebrafish lines induced by different parts of the Fugu (a,c,e,g,i,k,m,n,p) or amphioxus (b,d,f,h,j,l,o,q) CNE at 30 hpf (a–f), 50 hpf (i–l,p,q) and 5 dpf (g,h,m,n,o). Elevated levels of GFP in different brain regions (a,c) are indicated by arrows (fb, forebrain; mb, midbrain; hb, hindbrain). Arrows indicate expression in the hypothalamus (g,h,o), ear (i,j) and spinal cord KA-neurons (k,l).

Quantification of GFP expression in the zebrafish lens. (a–d) Co-injection of CNE17::GFP reporter constructs (a) and an RFP lens standard (b) is used to measure relative GFP intensity in the lens at 52 hpf ((c, brightfield), (d, merged)). (e) Relative GFP intensity for full-length versions, LSR or core regions of CNE17 from different species. p-values Mann–Whitney test (electronic supplementary material, dataset S3), ‘n.s.’ = p > 0.05.