Fig. 3

Later phenotypes of sbntc24 mutant embryos, 36 hpf, lateral view. (A) Wild type; (B) dominant maternal effect of sbn, causing strong C4 dorsalization. (C) Dominant zygotic effect of sbn, causing weak C1 dorsalization (arrow to ventral tail fin deficiency). (D) sbn,swr double heterozygote from a cross of a swr heterozygous female and a sbn heterozygous male, characterized by a loss of the ventral tail fin and a wound-up tail (C3, arrow), indicating a significantly stronger dorsalization than in C. (E-H) The maternal effect of sbn in the background of different sbn genotypes, 48 hpf, lateral view; (E-G) Embryos from a cross of two sbn heterozygous parents; (H) embryo from a cross of a sbn homozygous female with a heterozygous male. Both crosses led to offspring with 100% C4 dorsalization. The maternal and zygotic genotypes of individual embryos are indicated. The zygotic genotype was determined by tetra-PCR after photography.