Genomic signatures suggesting adaptation to ocean acidification in a coral holobiont from volcanic CO2 seeps

• Published in: Communications Biology
• Main Authors: Carlos Leiva, Rocío Pérez-Portela, Sarah Lemer
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2023
• Subjects: Biology (General); QH301-705.5; Ocean acidification
• Online Access: https://doi.org/10.1038/s42003-023-05103-7; https://doaj.org/article/b4ba7fed933e4179b2aa0f178b0ca2a3

Abstract Ocean acidification, caused by anthropogenic CO2 emissions, is predicted to have major consequences for reef-building corals, jeopardizing the scaffolding of the most biodiverse marine habitats. However, whether corals can adapt to ocean acidification and how remains unclear. We addressed these questions by re-examining transcriptome and genome data of Acropora millepora coral holobionts from volcanic CO2 seeps with end-of-century pH levels. We show that adaptation to ocean acidification is a wholistic process involving the three main compartments of the coral holobiont. We identified 441 coral host candidate adaptive genes involved in calcification, response to acidification, and symbiosis; population genetic differentiation in dinoflagellate photosymbionts; and consistent transcriptional microbiome activity despite microbial community shifts. Coral holobionts from natural analogues to future ocean conditions harbor beneficial genetic variants with far-reaching rapid adaptation potential. In the face of climate change, these populations require immediate conservation strategies as they could become key to coral reef survival.