Event Abstract Back to Event ONTOGENY OF LEPTIN SIGNALING IN HYPOTHALAMIC FEEDING CONTROL CENTERS IN THE FROG XENOPUS LAEVIS Melissa Cui1, Caroline Hu1, Chris Pelletier1 and Robert J. Denver1* 1 University of Michigan, Department of Molecular, Cellular, and Developmental Biology, United States The hormone leptin is well known to act on hypothalamic feeding control centers to reduce food intake in adults, but little is known about leptin’s anorectic action during postembryonic development in any species. Using tadpoles of the frog Xenopus laevis we investigated the ontogeny of leptin mRNA expression and leptin actions on feeding, and correlated this with the expression of leptin receptor (LepR) and key hypothalamic feeding control genes. Analysis of gut contents throughout metamorphosis showed that tadpoles ceased feeding at metamorphic climax. Leptin mRNA levels peaked at this stage in the body region containing the fat pads. Intracerebroventricular (i.c.v.) injection of recombinant frog leptin (rxLeptin; 20 ng/g body weight) potently inhibited feeding in late prometamorphic, but not premetamorphic, tadpoles. LepR mRNA was expressed at a low level in premetamorphic tadpole preoptic area/hypothalamus; expression increased throughout metamorphosis and peaked in the metamorphic frog. Similar ontogenetic increases were seen for feeding control genes: proopiomelanocortin, corticotropin-releasing factor, neuropeptide Y, adenosine monophosphate activated protein kinase, and suppressor of cytokine signaling 3 (SOCS3). The increase in LepR mRNA correlated with functional LepR signaling as analyzed by immunohistochemistry for phosphorylated signal transducer and activator of transcription 3 (pSTAT3) and RTqPCR for SOCS3, a leptin-induced STAT3 target gene. Injection of rxLeptin i.c.v. increased pSTAT3 immunoreactivity (ir) in the parvocellular anterior preoptic area, ventral hypothalamic area, and anterior pituitary, with maximal pSTAT3-ir induced at metamorphic climax. rxLeptin increased SOCS3 mRNA in prometamorphic, but not premetamorphic tadpoles. Our findings show that the anorectic action of leptin develops in the tadpole during metamorphosis, and this correlates with upregulation of LepR and key hypothalamic feeding control genes. Acknowledgements Supported by NSF grant IOS 0641587 to RJD Keywords: food intake, Leptin, metamorphosis, Ontogeny, Xenopus Conference: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology, Ann Arbor, United States, 13 Jul - 16 Jul, 2011. Presentation Type: Oral Presentation Topic: Metabolism and feeding Citation: Cui M, Hu C, Pelletier C and Denver RJ (2011). ONTOGENY OF LEPTIN SIGNALING IN HYPOTHALAMIC FEEDING CONTROL CENTERS IN THE FROG XENOPUS LAEVIS. Front. Endocrinol. Conference Abstract: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology. doi: 10.3389/conf.fendo.2011.04.00013 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 18 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Prof. Robert J Denver, University of Michigan, Department of Molecular, Cellular, and Developmental Biology, Ann Arbor, United States, rdenver@umich.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Melissa Cui Caroline Hu Chris Pelletier Robert J Denver Google Melissa Cui Caroline Hu Chris Pelletier Robert J Denver Google Scholar Melissa Cui Caroline Hu Chris Pelletier Robert J Denver PubMed Melissa Cui Caroline Hu Chris Pelletier Robert J Denver Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.