A Transcriptomic Analysis of Phenotypic Plasticity in Crassostrea virginica Larvae under Experimental Acidification

• Published in: Genes
• Main Authors: Michelle Barbosa, Caroline Schwaner, Emmanuelle Pales Espinosa, Bassem Allam
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2022
• Subjects: oyster; ocean acidification; RNASeq; acclimation; Genetics; QH426-470; Ocean acidification
• Online Access: https://doi.org/10.3390/genes13091529; https://doaj.org/article/8e3fc20e23e042ac845ebff01990261e

Ocean acidification (OA) is a major threat to marine calcifiers, and little is known regarding acclimation to OA in bivalves. This study combined physiological assays with next-generation sequencing to assess the potential for recovery from and acclimation to OA in the eastern oyster ( Crassostrea virginica ) and identify molecular mechanisms associated with resilience. In a reciprocal transplant experiment, larvae transplanted from elevated p CO 2 (~1400 ppm) to ambient p CO 2 (~350 ppm) demonstrated significantly lower mortality and larger size post-transplant than oysters remaining under elevated p CO 2 and had similar mortality compared to those remaining in ambient conditions. The recovery after transplantation to ambient conditions demonstrates the ability for larvae to rebound and suggests phenotypic plasticity and acclimation. Transcriptomic analysis supported this hypothesis as genes were differentially regulated under OA stress. Transcriptomic profiles of transplanted and non-transplanted larvae terminating in the same final p CO 2 converged, further supporting the idea that acclimation underlies resilience. The functions of differentially expressed genes included cell differentiation, development, biomineralization, ion exchange, and immunity. Results suggest acclimation as a mode of resilience to OA. In addition, the identification of genes associated with resilience can serve as a valuable resource for the aquaculture industry, as these could enable marker-assisted selection of OA-resilient stocks.