title: Internal pigment cells respond to external UV radiation in frogs.
abstract: Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation.
authors.affiliation: Department of Biology, São Paulo State University (UNESP), São José do Rio Preto, São Paulo 15054-000, Brazil Sven Lovén Centre for Marine Sciences - Kristineberg, University of Gothenburg, SE-451 78 Fiskebäckskil, Sweden lilian.belussi@gmail.com.
authors.forename: Lilian
authors.initials: L
authors.lastname: Franco-Belussi
authors.affiliation: Sven Lovén Centre for Marine Sciences - Kristineberg, University of Gothenburg, SE-451 78 Fiskebäckskil, Sweden.
authors.forename: Helen
authors.initials: H
authors.lastname: Nilsson Sköld
authors.affiliation: Department of Biology, São Paulo State University (UNESP), São José do Rio Preto, São Paulo 15054-000, Brazil.
authors.forename: Classius
authors.initials: C
authors.lastname: de Oliveira
mesh_terms: D000818:Animals; D001001:Anura / Q000235:genetics / Q000502:physiology*; D004249:DNA Damage / Q000528:radiation effects*; D006321:Heart / Q000502:physiology / Q000528:radiation effects; D008099:Liver / Q000502:physiology / Q000528:radiation effects; D008297:Male; D008407:Mast Cells / Q000378:metabolism / Q000528:radiation effects; D008543:Melanins / Q000032:analysis / Q000378:metabolism*; D008544:Melanocytes / Q000378:metabolism / Q000528:radiation effects; D010858:Pigmentation / Q000528:radiation effects*; D013737:Testis / Q000502:physiology / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D008543:Melanins
keywords: Anuran; DNA damage; Melanocytes; Melanomacrophages; Physalaemus nattereri; Solar radiation