Target gene expression studies on Platynereis dumerilii and Platynereis cfr massiliensis at the shallow CO2 vents off Ischia, Italy

Many studies predict negative effects of ocean acidification on marine organisms, potentially leading to loss of biodiversity and ecosystem function. Research on species inhabiting naturally high pCO(2) environments, such as volcanic CO2 vents, offers an opportunity to understand the molecular mechanisms involved in high pCO(2) regulation. Here we investigate the relative expression of NADH dehydrogenase, sodium-hydrogen antiporter (NHE), carbonic anhydrase (CA) and paramyosin genes from two non-calcifying sibling Nereididae polychaetes species, Platynereis cfr massiliensis, collected in the shallow CO2 vents off Ischia (Italy; 40 degrees 43'52.0 '' N 13'57'46.2 '' E and 40 '' 43'55.5 '' N 13'57'48.4 '' E), and P. dumerilii collected in an area nearby (4043'34.51 '' N: 13'57'35.7 '' E). The origin of the worms was confirmed using restriction enzyme digest. NHE and paramyosin expressions were both significantly increased in P. dumerilii relative to the P. cfr massiliensis vent populations. Furthermore, a seven day laboratory transfer experiment to lower/higher pCO(2) conditions was conducted to investigate the effects on the short term gene expression. The transfer experiment of the non-vent worms to high pCO(2) conditions showed no significant effect on any of the genes analysed, however, two genes (NADH dehydrogenase and NHE) from worms of the vent population were significantly down-regulated under low pCO(2). These findings will help to gain further insights into the cellular mechanisms affected by pCO(2) changes in two polychaete species. (C) 2017 Elsevier Ltd. All rights reserved.