Penguin acclimatization to polar environmental constraints : a transcriptomic and integrative study in King (Aptenodytes patagonicus) and Adélie penguins (Pygoscelis adeliae).

• Main Author: Dégletagne, Cyril
• Other Authors: Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard - Lyon I, Claude Duchamp, Mireille Raccurt
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2011
• Subjects: King penguin; Adélie penguin; Transcriptomic analysis; Microarray; Integrative physiology; Metabolism; Oxydative stress; Growth; Thermogenesis; Puces à ADN; Physiologie intégrative; Métabolisme énergétique; Stress oxydant; Croissance; Thermogenèse; Manchot Royal; Manchot Adélie; Analyse du transcriptome; [SDV.SA]Life Sciences [q-bio]/Agricultural sciences; Manchot; Manchots; King Penguins; Pygoscelis adeliae
• Online Access: https://tel.archives-ouvertes.fr/tel-00755130; https://tel.archives-ouvertes.fr/tel-00755130/document; https://tel.archives-ouvertes.fr/tel-00755130/file/TH2011_Degletagne_Cyril.pdf

King penguins have successfully colonized cold ecosystems of the southern hemisphere by developing physiological mechanisms that are not well understood. The aim of this study was to investigate, at different integrative levels from the gene to the whole animal, the functional responses developed by penguins to overcome polar constrains. We focused on acclimatization mechanisms enabling the first departure to sea of king penguin immatures and the rapid growth of Adélie penguin chicks.To explore differentially expressed genes in pectoralis muscle during penguin’s first sea acclimatization, we used Affymetrix microarrays design for chicken. We first set up and validated a new method to analyze heterologous hybridization transcriptomic profiles. We highlighted a selective shift in metabolic pathways favoring the use of lipids as fuel to sustain highly energetic needs imposed by marine life-style. Our results revealed a development of a global antioxidant response, potential consequences of penguin marine life-style that imposes repeated dives under apnea.Secondly, our integrative study on Adélie penguin’s chick revealed the development of molecular and cellular mechanisms which sustain an original strategy by first allocating most of the energy to growth and then promoting thermogenic processes.Our results showed that both king and Adélie penguins develop complex and coordinated physiological responses to energetic constraints highlighting their high phenotypic plasticity.