Fig. 7

Fig. 7 spaw regulates asymmetric gene expression. (A-C) Seventeen to 18 somite stage, DNP-netrin + DNP-spaw probes. Arrows indicate netrin (net) in the CNS. Arrowheads indicate the presence (A,C) or absence (B) of spaw in the left lateral plate. Asterisk indicates spaw expression in the tailbud. (A) 10 ng NCMO; (B) 10 ng Spaw-MO1; (C) uninjected (u). (D) Twelve to 14 somite stage, Dig-oep probe. (Top) Uninjected; (Bottom) injected with 14 ng Spaw- MO1. (E) Twenty-two to 24 somite stage; Dig-pitx2 probe, dorsal view of embryos injected with 10 ng NCMO (left), 10 ng of Spaw-MO1 (middle) or not injected (right). Black arrows indicate position of left-sided pitx2c near gut. Black arrowheads indicate bilateral pitx2a/2c in putative Rohon-Beard neurons. (F) Twenty to 22 somite stage; Dig-lefty2 probe; dorsal view with anterior towards the top. (Left) 10 ng Spaw-MO1 treated; (Right) 10 ng NC-MO treated. Arrowheads indicate presence (right) or absence (left) of left-sided lefty2 domain. (G) Nineteen to 22 somite stage; Diglefty1 probe; dorsal view with anterior towards the top. (Right) Uninjected; (Left) injected with 10 ng Spaw- MO1. Arrowheads indicate presence (right) or absence (left) of left-sided lefty1 domain in heart. (H) Nineteen to 22 somites, lateral view, anterior towards the left. Dig-lefty1 probe. Embryos injected with 10 ng of Spaw- MO1 (left) or of NC-MO (right). Asterisks indicate site of lefty1 expression domain in posterior notochord. Arrowheads indicate location of lefty1 domain on left side of dorsal diencephalon. (I-K) Eighteen to 22 somites; DNP-cyclops probe; lateral view of head, anterior towards the left. (I) Embryo injected with 10 ng of NC-MO. (J) Embryo injected with 10 ng Spaw-MO1. (K) Uninjected embryo. Arrowheads indicate expression (I,K) or absence (J) of cyclops in the left part of the dorsal diencephalon. (L,M) Twelve to 14 somites, anterior towards the bottom; Dig-oep probe, dorsal view, focusing on the epiphysis. (L) Uninjected embryo. (M) Embryo injected with 14 ng Spaw-MO1. (N,O) Nineteen to 23 somites; Dig-flh probe, dorsal view, focusing on epiphysis. (N) Uninjected embryo. (O) Embryo injected with 10 ng Spaw-MO2. (P,Q) Twenty-one to 23 somite stage; DNP-pitx2 probe; lateral views (left side), anterior towards the left. Arrowheads indicate region of the dorsal diencephalon where pitx2c mRNA is normally restricted to the left side. (P) Embryo injected with 10 ng of Spaw-MO1. (Q) Uninjected embryo. (R,S) Twenty-one to 23 somite stage, DNP-pitx2 probe, frontal view. Arrowheads indicate region of the dorsal diencephalon where pitx2c mRNA is normally restricted to the left side. (R) Embryo injected with 10 ng of Spaw-MO1. (S) Embryo injected with 10 ng of NC-MO. (T-W) Sixteen to 18 somite stage; anterior is towards the top, dorsal view. DNP-spaw (–MATR) probe is specific for endogenous spaw transcripts. (T) Uninjected embryo. (U) Embryo injected with 9 ng of Spaw-MO1. (V,W) Two examples of ‘spaw-reversed’ embryos, achieved by co-injection of 9 ng Spaw-MO1 and 40 pg ActHASpaw RNA