Effects of low seawater pH on the marine polychaete Platynereis dumerilii

Mar Pollut Bull. 2015 Jun 15;95(1):166-72. doi: 10.1016/j.marpolbul.2015.04.027. Epub 2015 Apr 22.

Abstract

An important priority for any organism is to maintain internal cellular homeostasis including acid-base balance. Yet, the molecular level impacts of changing environmental conditions, such as low pH, remain uncharacterised. Herein, we isolate partial Na(+)/H(+)exchangers (NHE), carbonic anhydrase (CA), and calmodulin (CaM) genes from a polychaete, Platynereis dumerilii and investigate their relative expression in acidified seawater conditions. mRNA expression of NHE was significantly down-regulated after 1h and up-regulated after 7days under low pH treatment (pH 7.8), indicating changes in acid-base transport. Furthermore, the localisation of NHE expression was also altered. A trend of down regulation in CA after 1h was also observed, suggesting a shift in the CO2 and HCO3(-) balance. No change in CaM expression was detected after 7days exposure to acidified seawater. This study provides insight into the molecular level changes taking place following exposure to acidified seawater in a non-calcifying, ubiquitous, organism.

Keywords: Acid–base regulation; Gene expression; Low pH; P. dumerilii; Polychaeta.

MeSH terms

  • Animals
  • Calmodulin / genetics
  • Carbonic Anhydrases / genetics
  • Gene Expression Regulation
  • Hydrogen-Ion Concentration
  • Polychaeta / physiology*
  • RNA, Ribosomal, 18S
  • Seawater* / chemistry
  • Sodium-Hydrogen Exchangers / genetics

Substances

  • Calmodulin
  • RNA, Ribosomal, 18S
  • Sodium-Hydrogen Exchangers
  • Carbonic Anhydrases