THE EFFECT OF AMBIENT TEMPERATURES OF TWO THREATENED CARIBBEAN CORAL SPECIES: A PROTEOMIC STUDY

Martha Ricaurte1, Nikolaos V Schizas2, Ernesto Weil2, Pawel Ciborowski3 and Nawal M Boukli4, (1)University of Puerto Rico Mayaguez, Mayaguez, PR, United States, (2)University of Puerto Rico, Department of Marine Sciences, Mayaguez, PR, United States, (3)Director, Mass Spectrometry and Proteomics Core Facility, Omaha, NE, United States, (4)Professor, Microbiology and Immunology, Bayamon, PR, United States
Abstract:
Coral reefs are among the most valuable ecosystems on the earth. Increasing water temperatures as a consequence of global warming have been identified, as an overriding cause of coral decline (e.g. increased incidence of diseases, bleaching), and one of the regions that has been identified vulnerable to climatic changes, is the Caribbean. Laboratory experiments have shown negative effects of different temperatures in coral growth, larval and adult survival, and gene expression. In order to understand the molecular and cellular basis in the protein regulation during changes in temperature in the field, a comparative proteomic analysis associated with thermal fluctuations was made from wet and dry season of 2014. In the study, we investigated alterations in proteins of Acropora palmata and Orbicella faveolata by two-dimensional gel electrophoresis (2D-GE) followed by liquid chromatography-tandem mass spectrometry, protein identification, and confirmation at the gene expression level by qRT-PCR.

Proteomes of related samples demonstrated 195 differentially expressed proteins (DEP) in A. palmata during dry season and 108 (DEP) during wet season of 2014. O. faveolata overexpressed 62 (DEP) in dry season and 190 (DEP) during wet season of 2014. All proteins had a two-fold or greater change in expression due to temperature, altering several components of the cellular stress response that include chaperones, stress proteins, antioxidant enzymes, proteases, cytoskeletal and apoptosis regulating proteins. Our results suggest that A. palmata and O. faveolata display a distinct response by expressing these key protein signatures in dry and wet season. This proteomic approach may open new avenues of research to detect potential early biomarkers involved in response to these stressors, during seasonal changes in water temperatures. The results provide insight into targets and mechanistic strategies to detect potential markers involved in response to temperature change for A. palmata and O. faveolata during seasonal changes in water temperatures.