title: Metabolic plasticity for subcutaneous fat accumulation in a long-distance migratory bird traced by2H2O.
abstract: The migrant black-tailed godwit (Limosa limosa) traditionally used natural wetlands in the Iberian Peninsula to prepare for migratory flights by feeding mainly in estuaries. In recent decades, this species has become increasingly dependent on rice fields, thereby relying on a plant-based diet for fuelling. Dietary fatty acids (FA) seem to be determinant to the composition of accumulated subcutaneous fat in migratory birds. It is still unclear whether metabolic plasticity allows for modification and/or synthesis of FA, contributing to a lipid profile that enables a successful migratory performance. Deuterated water was administered to captive black-tailed godwits submitted to two diets (fly larvae versus rice) and the incorporation of deuterium (2H) into subcutaneous triglycerides was analyzed by NMR. A recently developed localized biopsy method for sampling subcutaneous fat was employed with later successful release of all birds into the wild. The average chemical structure reflected mostly a mixture of saturated and monounsaturated 16- and 18-carbon FA, a profile frequently found in migrant birds. Significantly higher levels of polyunsaturated FA, as well as detectable levels of n-3 FA, were observed in fly-larvae-fed birds. Excess2H-enrichments in FA revealed significantly higher rates of fractionalde novolipogenesis and FA desaturation capacity in rice-fed birds. This novel and non-lethal tracer method revealed the capacity of this species to alter its lipid metabolism to compensate for a poorer dietary lipid contribution. Because of its versatility, adapting this method to other scenarios and/or other migratory species is considered feasible and cost-effective.
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra 3004-517, Portugal iviegas@ci.uc.pt.|CFE - Center for Functional Ecology, Department Life Sciences, University of Coimbra, Coimbra 3000-456, Portugal.
authors.forename: Ivan
authors.identifier: 0000-0003-2589-2212
authors.initials: I
authors.lastname: Viegas
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Coimbra 3000-456, Portugal.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Araújo
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Coimbra 3000-456, Portugal.
authors.forename: Afonso D
authors.initials: AD
authors.lastname: Rocha
authors.affiliation: Conservation Biology Research Group, Área de Zoología, Universidad de Extremadura, Avenida de Elvas s/n, Badajoz 06071, Spain.
authors.forename: Auxiliadora
authors.initials: A
authors.lastname: Villegas
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra 3004-517, Portugal.
authors.forename: John G
authors.initials: JG
authors.lastname: Jones
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Coimbra 3000-456, Portugal.
authors.forename: Jaime A
authors.initials: JA
authors.lastname: Ramos
authors.affiliation: Conservation Biology Research Group, Área de Zoología, Universidad de Extremadura, Avenida de Elvas s/n, Badajoz 06071, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Masero
authors.affiliation: CESAM, Dep. Biologia, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro 3180-193, Portugal.|University of Iceland, South Iceland Research Centre, Fjölheimer, Bankavegur, Selfoss IS-800, Iceland.
authors.forename: José A
authors.initials: JA
authors.lastname: Alves
mesh_terms: D025041:Animal Migration; D000818:Animals; D046091:Charadriiformes / Q000502:physiology*; D003903:Deuterium / Q000378:metabolism; D004041:Dietary Fats / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D050356:Lipid Metabolism; D050155:Lipogenesis; D009682:Magnetic Resonance Spectroscopy; D050151:Subcutaneous Fat / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D014280:Triglycerides; D014867:Water; D003903:Deuterium
keywords: Deuterated water; Godwits; Lipid accumulation; Lipogenesis; Migration; NMR