Fig. 4. Roles of Tcf7 and Lef1 in the pectoral fin outgrowth. (A-C) Microinjection of lef1-MO into HG21C embryos. The pectoral fins of MO-injected heterozygous (A) and homozygous (B) embryos at 72 hpf. (C) Summary of the numbers of MO-injected embryos that showed an outgrown fin or reduced fin phenotype. (D-U) The pectoral fins of lef1-MO-injected wild-type and HG21C embryos analyzed by whole-mount in situ hybridization. The stages (28 hpf, 36 hpf, 38 hpf and 48 hpf) are shown on the top right. Wild-type (D-H,J,L,N,P,R), heterozygous (T) and homozygous (I,K,M,O,Q,S,U) embryos were used. The probes used are indicated (top right).