Recombinant plasmids comprising (a) a ubiquitous promoter, (b) one
fluorescent gene, the gene being operably liked to and inserted
downstream of the ubiquitous promoter, (c) a skin-specific or
muscle-specific promoter, and (d) another fluorescent gene, the gene
being operably linked to and inserted downstream the skin-specific or
muscle specific promoter. The ubiquitous promoter and the skin-specific
or muscle promoter have the adverse directional property and the
ubiquitous promoter and the skin-specific or muscle-specific promoter are
located upstream of the fluorescent gene and the another fluorescent gene
respectively so as to have the directional property which permits
transcription of the genes. Host cells, transgenic fish harboring the
plasmid of the invention and methods of producing a transgenic fish can
be made with the plasmids of the invention.