2026/01/17 by Yitian Bai, Yue Min, Shikai Liu +7 · 1 voice · 2 citations
Biochemistry, Genetics and Molecular Biology · Materials Science · Engineering · #Developmental Biology and Gene Regulation #Calcium Carbonate Crystallization and Inhibition #Marine Biology and Environmental Chemistry
paper · doi:10.1093/molbev/msag019
openalex publication_date 2026/01/17 · openalex created_date 2026/01/21 · openalex updated_date 2026/07/31
Biomineralized skeletons have evolved convergently across animals and exhibit remarkable diversity in structure and development. However, the evolutionary origins of gene regulatory networks underlying biomineralized skeletons remain elusive. Here, we report comprehensive developmental profiling of transcriptomic and chromatin dynamics in a bivalve mollusc, Crassostrea nippona. We provide evidence for a biphasic regulatory program orchestrating larval and adult shell formation, involving the coordinated activity of ancient transcription factors and dynamic chromatin remodeling. Comparative analyses suggest a conserved developmental toolkit was co-opted for larval exoskeleton formation in the common lophotrochozoan ancestor. In contrast, limited regulatory conservation was observed between lophotrochozoans and echinoderms with regard to the formation of biomineralized skeletons, despite both relying on a heterochronic activation of ancestral regulators. Together, our findings support a hierarchical model in which dynamic chromatin decouples rapidly evolving effectors from deeply conserved regulators, allowing modular innovations within conserved gene regulatory networks. This study highlights how epigenetic dynamics bridge evolutionary conservation and novelty, offering a framework for understanding the independent evolution of biomineralization across Bilateria through combinatorial regulatory evolution.