Tryptophan hydroxylase Is Required for Eye Melanogenesis in the Planarian Schmidtea mediterranea.

ABSTRACT: Melanins are ubiquitous and biologically important pigments, yet the molecular mechanisms that regulate their synthesis and biochemical composition are not fully understood. Here we present a study that supports a role for serotonin in melanin synthesis in the planarian Schmidtea mediterranea. We characterize the tryptophan hydroxylase (tph) gene, which encodes the rate-limiting enzyme in serotonin synthesis, and demonstrate by RNA interference that tph is essential for melanin production in the pigment cups of the planarian photoreceptors. We exploit this phenotype to investigate the biological function of pigment cups using a quantitative light-avoidance behavioral assay. Planarians lacking eye pigment remain phototactic, indicating that eye pigmentation is not essential for light avoida

SUBMITTER: Lambrus BG 

PROVIDER: S-EPMC4446096 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature