AUTHOR=Ruggeri Maria , Zhang Yingqi , Aglyamova Galina V. , Kenkel Carly D. 

TITLE=Divergent transcriptional response to thermal stress among life stages could constrain coral adaptation to climate change

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1163552

DOI=10.3389/fmars.2023.1163552

ISSN=2296-7745

ABSTRACT=The ability for adaptation to track environmental change depends on how efficiently selection can act on heritable genetic variation. Complex life cycles may promote or constrain adaptation depending on the integration or independence of fitness-related traits over development. Reef-building corals exhibit life cycle complexity and are sensitive to increasing temperatures, highlighting the need to understand heritable potential of the thermal stress response and its developmental regulation. We used tag-based RNA-seq to profile holobiont gene expression of inshore and offshore P. astreoides adults and recruit offspring in response to a 16-day heat stress, and larvae in response to a 4-day heat stress. Developmental stage affected both host and symbiont expression and modulated the stress response, suggesting host life-stage influences the holobiont response to selection. Populations also exhibited origin-specific treatment responses, but response magnitude differed among life-stages. Inshore parents and recruit offspring exhibited a more robust stress response than offshore-origin corals, indicating expression plasticity may be heritable. However, larval populations exhibited the opposite response, possibly due to stage-specific effects or exposure duration. Overall, these results show that putatively adaptive regulatory variation can be heritable, but thermally responsive genes are stage-specific, which will complicate the evolutionary response of coral to climate change.