Fig. 7

Eda signaling and the maintenance of anterior-posterior pattern in late paired fin development.

Analysis of edar (A–B, E–F), shh (C–D, G–H), and bmp2b (I–L) expression in developing pectoral (A–D, –J) and pelvic fins (E–H, K–L) from 8 mm juvenile fish of wild type (A, E; C, G; I, K) and fls^te370f mutant fish (B, F; D, H; J, L). A–B) Arrowheads indicate two distinct patterns of edar expression in the pectoral fin: an expression that marks the posterior edge and distal region of the development of the proximal radials (black); and a posterior bias of edar expression in the forming lepidotrichia (white). Arrows point out the remaining posterior expression in mutant fins. Brackets in all panels outline anterior deficiencies in gene expression in fls mutant fins. M–P, analysis of patterns of cell death in the developing paired fins by retention of acridine orange stain. N, P) Arrows point out anterior distal regions of cell death in both pectoral and pelvic fins from the mutant; (M, N) pectoral fin and (O, P) pelvic fin respectively. Q, R) Expression of msxa in wild type and mutant pectoral fins. Region of expression outlined with brackets; asterisk marks an ectopic site of expression.