Expression of zebrafish dpr1 is dynamic from high through 30% epiboly, relative to zebrafish dpr2. A-H: Zebrafish dpr1 expression. I-P: Zebrafish dpr2 expression. A,C,E,G,I,K,M,O are lateral views. B,D,F,H,J,L,N,P are animal views. Dorsal is to the right.

Zebrafish dpr1 and dpr2 can be induced by Β-catenin, boz, or sqt RNA injections. Embryos are at 30% epiboly. A-H: Zebrafish dpr1 expression. I-P: Zebrafish dpr2 expression. A,B,I,J: Uninjected (Uninj.) wild-type control embryos. C,D,K,L: Stabilized Β-catenin RNA-injected embryos. E,F,M,N: boz RNA-injected embryos. G,H,O,P: sqt RNA-injected embryos. A,C,E,G,I,K,M,O are lateral views. B,D,F,H,J,L,N,P are animal views. Dorsal is to the right.

Zebrafish dpr1 and dpr2 require Β-catenin signaling for their dorsal expression. Embryos are at sphere stage. A-D: Zebrafish dpr1 expression. E-H: Zebrafish dpr2 expression. A,B,E,F: Uninjected (Uninj.) wild-type controls. C,D,G,H: Embryos injected with dn-tcf3 RNA do not have expression of dpr1 or dpr2. A,C,E,G are lateral views. B,D,F,H are animal views. Dorsal is to the right.

Nodal signaling is required for maintenance, but not initiation, of dpr1 expression. Embryos were probed for zebrafish dpr1. A-L: MZoep mutant embryos. M-X: Wild-type control embryos. Developmental stages are indicated. C,D: Arrowheads indicate decreased dpr1 expression in MZoep mutant embryos. O,P: Arrowheads indicate dorsal dpr1 expression in wild-type embryos. E-J: Arrows indicate ectodermal dpr1 expression. A,C,E,G,I,K,M,O,Q,S,U,W are lateral views. B,D,F,H,N,P,R,T are animal views. Dorsal is to the right, except in J,L,V,X, which are dorsal views. In J,L,V,X, anterior is upward. Note that, because later epiboly (epib.) movements are delayed in MZoep embryos, dpr1 expression in MZoep embryos at 70% and 90% epiboly is compared with wild-type embryos at 90% epiboly and tail bud stages, respectively.

Nodal signaling is required for maintenance, but not initiation, of dpr2 expression. Embryos were probed for zebrafish dpr2. A-L: MZoep mutant embryos. M-X: Wild-type control embryos. Developmental stages are indicated. G-L: Arrowheads in G and H and arrows in I,J,K,L indicate ectodermal dpr2 expression in MZoep mutant embryos. X: Arrows indicate ectodermal expression. A,C,E,G,I,K,M,O,Q,S,U,W are lateral views. B,D,F,H,N,P,R,T are animal views. Dorsal is to the right, except in J,L,V,X, which are dorsal views. In J,L,V,X, anterior is upward. Note that, because later epiboly (epib.) movements are delayed in MZoep embryos, dpr2 expression in MZoep embryos at 70% and 90% epiboly is compared with wild-type embryos at 90% epiboly and tail bud stages, respectively.

Boz and Nodal signaling are not required for initiation of dorsal dpr1 or dpr2 expression. Embryos are at sphere stage. A,B,E,F: Embryos from a boz intercross (Uninj.). C,D,G,H: Embryos from boz intercross injected with atv RNA. There was no discernible difference between dpr1 or dpr2 expression in wild-type embryos compared with embryos from boz carriers or boz carriers injected with atv RNA. A,C,E,G are lateral views. B,D,F,H are animal views. Dorsal is to the right.

Zebrafish dpr1 and dpr2 can be regulated by bone morphogenetic protein (BMP) signaling. Embryos are at sphere stage. A-F: Zebrafish dpr1 expression. G-L: Zebrafish dpr2 expression. Injected RNAs are indicated in the figure. C,D,I,J: Embryos injected with nog RNA have ectopic dpr1 and dpr2 expression. E,F,K,L: Embryos injected with bmp2b RNA have reduced expression of dpr1 and dpr2. A,C,E,G,I,K are lateral views. B,D,F,H,J,L are animal views. Dorsal is to the right.

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