Comparative somatic genomics reveals divergent development of cell lineages across scleractinian corals

Abstract

Somatic mutations may drive adaptation and aging across diverse life forms, yet their role remains poorly understood in many early-branching animals. Here, we compare somatic mutation accumulation in the robust coral Orbicella faveolata with previous findings in the complex coral Acropora palmata. Whole-genome sequencing revealed high fixation of somatic genetic variants in O. faveolata, particularly in older, interior regions of colonies--contrasting with A. palmata. These patterns suggest distinct cell population dynamics between clades, indicating a segregated, mammal-like germline in O. faveolata, whereas such a germline remains undetected in A. palmata. This underscores the diversity of somatic evolutionary mechanisms across scleractinian corals.