Nitric oxide in chromatic body patterning elements of Sepia officinalis

The spectacular variety of body coloration patterns in Sepia officinalis reflects the concerted activity of the skin chromatic elements, chromatophores, leucophores and iridophores. Recent studies have revealed that nitric oxide is an important messenger in the long term maintenance of the body coloration, inducing chromatophore expansion downstream glutamate activation. Herein we describe the presence of nitric oxide synthase and nitric oxide synthesis in isolated juvenile iridophores in Sepia. The possible roles of nitric oxide in the complex mechanisms leading to body coloration patterns in cephalopods are an important focus for ongoing and future studies.