title: Overview of the molecular defense systems used by sea urchin embryos to cope with UV radiation.
abstract: The sea urchin embryo is a well-recognized developmental biology model and its use in toxicological studies has been widely appreciated. Many studies have focused on the evaluation of the effects of chemical stressors and their mixture in marine ecosystems using sea urchin embryos. These are well equipped with defense genes used to cope with chemical stressors. Recently, ultraviolet radiation (UVR), particularly UVB (280-315 nm), received more attention as a physical stressor. Mainly in the Polar Regions, but also at temperate latitudes, the penetration of UVB into the oceans increases as a consequence of the reduction of the Earth's ozone layer. In general, UVR induces oxidative stress in marine organisms affecting molecular targets such as DNA, proteins, and lipids. Depending on the UVR dose, developing sea urchin embryos show morphological perturbations affecting mainly the skeleton formation and patterning. Nevertheless, embryos are able to protect themselves against excessive UVR, using mechanisms acting at different levels: transcriptional, translational and post-translational. In this review, we recommend the sea urchin embryo as a suitable model for testing physical stressors such as UVR and summarize the mechanisms adopted to deal with UVR. Moreover, we review UV-induced apoptotic events and the combined effects of UVR and other stressors.
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Biomedicina e Immunologia Molecolare "Alberto Monroy", Via Ugo La Malfa 153, 90146 Palermo, Italy. Electronic address: rosa.bonaventura@ibim.cnr.it.
authors.forename: Rosa
authors.initials: R
authors.lastname: Bonaventura
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Biomedicina e Immunologia Molecolare "Alberto Monroy", Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Matranga
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D004249:DNA Damage; D004625:Embryo, Nonmammalian / Q000502:physiology*; D018384:Oxidative Stress; D012617:Sea Urchins / Q000196:embryology* / Q000502:physiology; D013312:Stress, Physiological; D014466:Ultraviolet Rays
keywords: Developmental abnormalities; Echinoderm; Ionizing radiation; Sea urchin embryo; Signaling pathways; Stress response