RT Journal Article
SR Electronic
T1 Energetics but not development is impacted in coral embryos exposed to ocean acidification
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.07.19.452948
DO 10.1101/2021.07.19.452948
A1 EE Chille
A1 EL Strand
A1 F Scucchia
A1 M Neder
A1 V Schmidt
A1 MO Sherman
A1 T Mass
A1 HM Putnam
YR 2021
UL http://biorxiv.org/content/early/2021/07/20/2021.07.19.452948.abstract
AB In light of the chronic stress and mass mortality reef-building corals face under climate change, it is critical to understand the processes essential to reef persistence and replenishment, including coral reproduction and development. Here we quantify gene expression and size sensitivity to ocean acidification across a set of developmental stages in the rice coral, Montipora capitata. Gametes and then embryos and swimming larvae were exposed to three pH treatments ranging from 7.8 (Ambient), 7.6 (Low) and 7.3 (Xlow) from fertilization to 9 days post-fertilization. Embryo development and size, planula volume, and stage-specific gene expression were compared between treatments at each stage to determine the effects of acidified seawater on early development. While there was no measurable size differentiation between fertilized eggs and embryos at the prawn chip stage exposed to ambient, low, and extreme low pH, early gastrula and planula raised in reduced pH treatments were significantly smaller than those raised in ambient seawater, suggesting an energetic cost to developing under low pH. However, no differentially expressed genes emerged between treatments at any time point, except swimming larvae. Larvae from pH 7.6 showed upregulation of genes involved in cell division, regulation of transcription, lipid metabolism, and oxidative stress in comparison to the other two treatments, and smallest sizes in this treatment. While low pH appears to increase energetic demands and trigger oxidative stress, the developmental process is robust to this at a molecular level, with swimming larval stage reached in all pH treatments.Summary statement This developmental time series tracks the physiological and transcriptomic outcomes of early coral development under ambient pH (pH 7.8), and two low pH conditions (pH 7.6 and 7.3).Competing Interest StatementThe authors have declared no competing interest.CO2carbon dioxideOAocean acidificationMZTmaternal-to-zygotic transitionUVultravioletROSreactive oxygen specieshpfhours post-fertilizationLPHliters per hourdpfdays post-fertilizationvstvariance stabilizing transformationPCAprincipal components analysisGOgene ontologyDEGdifferentially-expressed genePEpaired-end