title: Adaptive downregulation of pheomelanin-related Slc7a11 gene expression by environmentally induced oxidative stress.
abstract: Pheomelanin is a sulphur-containing yellow-to-reddish pigment whose synthesis consumes the main intracellular antioxidant (glutathione; GSH) and its precursor cysteine. Cysteine used for pheomelanogenesis cannot be used for antioxidant protection. We tested whether the expression of Slc7a11, the gene regulating the transport of cysteine to melanocytes for pheomelanogenesis, is environmentally influenced when cysteine/GSH are most required for antioxidant protection. We found that zebra finches Taeniopygia guttata developing pheomelanin-pigmented feathers during a 12-day exposure to the pro-oxidant diquat dibromide downregulated the expression of Slc7a11 in feather melanocytes, but not the expression of other genes that affect pheomelanogenesis by mechanisms different from cysteine transport such as MC1R and Slc45a2. Accordingly, diquat-treated birds did not suffer increased oxidative stress. This indicates that some animals have evolved an adaptive epigenetic lability that avoids damage derived from pheomelanogenesis. This mechanism should be explored in human Slc7a11 to help combat some cancer types related to cysteine consumption.
authors.affiliation: cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
authors.forename: Ismael
authors.initials: I
authors.lastname: Galván
authors.affiliation: cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
authors.forename: Ângela
authors.initials: Â
authors.lastname: Inácio
authors.affiliation: Instituto de Investigación en Recursos Cinegéticos (IREC) - CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005, Ciudad Real, Spain.
authors.forename: Ana Angela
authors.initials: AA
authors.lastname: Romero-Haro
authors.affiliation: Instituto de Investigación en Recursos Cinegéticos (IREC) - CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005, Ciudad Real, Spain.|Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales - CSIC, C/José Gutiérrez Abascal 2, 28006, Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Alonso-Alvarez
mesh_terms: D027182:Amino Acid Transport System y+ / Q000235:genetics*; D000818:Animals; D003545:Cysteine / Q000378:metabolism; D004178:Diquat; D015536:Down-Regulation; D044127:Epigenesis, Genetic; D005241:Feathers; D046369:Finches / Q000235:genetics*; D008543:Melanins / Q000235:genetics*; D018384:Oxidative Stress; D010858:Pigmentation
chemical_list: D027182:Amino Acid Transport System y+; D008543:Melanins; C018362:pheomelanin; D004178:Diquat; D003545:Cysteine
keywords: 
  Slc7a11
  ; environmental epigenetics; oxidative stress; pheomelanin; pigmentation