Stress-induced changes in color expression mediated by iridophores in a polymorphic lizard

Abstract

Stress is an important potential factor mediating a broad range of cellular pathways, including those involved in condition-dependent (i.e., honest) color signal expression. However, the cellular mechanisms underlying the relationship between stress and color expression are largely unknown. We artificially elevated circulating corticosterone levels in male tawny dragon lizards, Ctenophorus decresii, to assess the effect of stress on the throat color signal. Corticosterone treatment increased luminance (paler throat coloration) and decreased the proportion of gray, thereby influencing the gray reticulations that produce unique patterning. The magnitude of change in luminance for corticosteron..