Fig. 7. LvDelta expressed by mesomeres is sufficient to induce pigment cell formation by macromeres. (A) Experimental design. Micromeres were removed from an unlabeled embryo to generate the host. Fertilized eggs were injected with the truncated or full-length form of LvDelta mRNA and one mesomere was isolated at the 16-cell stage and transplanted to the vegetal pole of the host embryo. (B) A micromere(–) embryo recombined with a mesomere expressing truncated LvDelta develops few pigment cells. (C) Epifluorescence image of the larva in B demonstrates that the transplanted mesomere contributes to the foregut and midgut. (D) A micromere(–) embryo recombined with a mesomere expressing full-length LvDelta develops many pigment cells. (E) Epifluorescence of the larva in D shows that the transplanted mesomere contributes to the foregut and mesoderm. Many mesodermal cells do not contain the lineage tracer and were derived from host tissue.
