Figure 5

Gene expression in the WE of control and denervated fins. a-x) mRNA ISH on whole mount amputated fins: lef1, wnt5b, pea3, krt8. a’-x’) Longitudinal sections of the rays using whole mount ISH. a-g) Lef1 is expressed from 0.5 to 1.5 dpa in the BEL of both control (a,c,e) and denervated fins (b,d,f,g). At 1.5 dpa lef1 is expressed in the inter-ray region of non-regenerating (f) and partially regenerating denervated fins, where it forms what seems a shared BEL on contiguous rays (g*). h-o) Wnt5b is expressed in the WE of both control (h,j,l,n) and denervated fins (i,k,m,o) from 0.5 to 4 dpa. [The arrowhead in h’ indicates expression, staining in the WE is an artefact]. In denervated fins, after 1.5 dpa, wnt5b presents a spread and de-regulated expression domain (m). p-s) Pea3 is expressed in both control and denervated fins at 0.5 and 1 dpa, with a reduced expression in denervated fins (q,s). In controls pea3 is expressed in the whole WE (p’,r’), while in denervates is restricted to the distal WE cells (q’,s’). t-x) Krt8 is expressed in both control (t,v) and denervated fins (u,x) at 0.5 and 1 dpa, with a reduced expression in denervates (u,x). While in controls krt8 is strongly expressed in the whole WE (t’,v’), in denervates it is restricted to some epidermal cells in the distal tip (u’,x’). a,a’-x,x’) Dashed lines mark amputation plane. Scale bar - 100 μm in whole mount; 25 μm in sections. y) qRT-PCR for genes expressed in the WE. qRT-PCR analysis shows a decrease in the expression levels of analysed genes on denervated fins, in relation to controls, from 0.5 to 2 dpa, except for wnt5b, which is increased at 0.5 dpa. Note: ***p < 0.0001, *p < 0.05. Data not evaluated for krt8 and fgf24, at 1.5 and 2 dpa.