Fig. 7. Suppression of muscle fate in non-muscle lineages by cell interactions is required for proper patterning of the posterovegetal quarter of early ascidian embryos. When cell interactions were inhibited by cell dissociation or treatment with MEK inhibitor, every B-line cell assumed muscle fate as directed by macho-1. macho-1 protein would distribute into all B-line cells (pink area). Mes, mesenchyme; TVC, trunk ventral cell.