title: Carbon dioxide induced plasticity of branchial acid-base pathways in an estuarine teleost.
abstract: Anthropogenic CO2is expected to drive ocean pCO2above 1,000 μatm by 2100 - inducing respiratory acidosis in fish that must be corrected through branchial ion transport. This study examined the time course and plasticity of branchial metabolic compensation in response to varying levels of CO2in an estuarine fish, the red drum, which regularly encounters elevated CO2and may therefore have intrinsic resilience. Under control conditions fish exhibited net base excretion; however, CO2exposure resulted in a dose dependent increase in acid excretion during the initial 2 h. This returned to baseline levels during the second 2 h interval for exposures up to 5,000 μatm, but remained elevated for exposures above 15,000 μatm. Plasticity was assessed via gene expression in three CO2treatments: environmentally realistic 1,000 and 6,000 μatm exposures, and a proof-of-principle 30,000 μatm exposure. Few differences were observed at 1,000 or 6,000 μatm; however, 30,000 μatm stimulated widespread up-regulation. Translocation of V-type ATPase after 1 h of exposure to 30,000 μatm was also assessed; however, no evidence of translocation was found. These results indicate that red drum can quickly compensate to environmentally relevant acid-base disturbances using baseline cellular machinery, yet are capable of plasticity in response to extreme acid-base challenges.
authors.affiliation: University of Texas at Austin, University of Texas Marine Science Institute, Port Aransas, TX 78373, USA.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Allmon
authors.affiliation: University of Texas at Austin, University of Texas Marine Science Institute, Port Aransas, TX 78373, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Esbaugh
mesh_terms: D000143:Acids / Q000378:metabolism*; D000222:Adaptation, Physiological; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism*; D005399:Fishes / Q000502:physiology*; D020869:Gene Expression Profiling; D026901:Membrane Transport Proteins / Q000378:metabolism*
chemical_list: D000143:Acids; D026901:Membrane Transport Proteins; D002245:Carbon Dioxide