“Contrasting thermal tolerance in corals emerges from temperature-induced gene network rewiring and isoform switching” (2026), by Federica Scucchia et al. Environmental Science research paper. Original abstract below, unchanged. A free PDF is available.

Contrasting thermal tolerance in corals emerges from temperature-induced gene network rewiring and isoform switching

Federica Scucchia, Pierrick Harnay, Hollie M. Putnam · November 1, 2026 · Environmental Science

Abstract

Organismal thermal tolerance will shape future coral reef function, as ocean warming drives extensive stress and mortality through increasingly frequent marine heatwaves. This is among the most apparent phenomena on reefs, where marine heatwaves can devastate reef-building corals, the ecosystem engineers, driving the breakdown of the coral-algae symbiosis, or coral bleaching. Coral resistance to bleaching varies markedly among species, reflecting differences in physiology underpinned by molecular regulatory mechanisms that are initiated early during heat stress and influence longer-term bleaching outcomes. Gene expression plasticity enables transcriptional adjustments to environmental stress, while alternative splicing and isoform switching further expand molecular adaptability by altering transcript diversity and abundance. Because genes function within combinatorial networks, changes in these network members and in the identity of highly influential hub genes can reveal higher-order biological reorganization under stress. Yet, the contribution of isoform switching to gene network dynamics remains unknown in corals. Here we integrate physiological performance, gene network topology, hub genes dynamics, and isoform switching across three Hawaiian corals, Porites compressa , Montipora capitata , and Pocillopora acuta, with known differences in thermal sensitivity to identify molecular processes shaping acute thermal responses. We show that the interplay between expression plasticity, hub gene rearrangement, and isoform switching drives species-specific thermal tolerance. Species-specific thermal tolerance was associated with differences in energetic status, with the most thermally tolerant species, P. compressa, exhibiting the highest energetic reserves. Network analysis uncovered extensive rewiring and temperature-responsive hub genes turnover regulated by switches in isoform usage. P. compressa shows stable constitutive gene expression and continuous isoform adjustments across temperatures, while fine-tuning thermal response through dedicated hub genes. In contrast, the most thermally sensitive species, P. acuta, shows broad transcriptomic shifts and isoform switching controlling the reorganization of network leadership at high temperatures. Together, these findings identify isoform switching as an under-explored regulatory mechanism linking early molecular responses to coral thermal resilience and species persistence in warming oceans.

Free PDF DOI: 10.1016/j.scitotenv.2026.182359