https://phaidra.vetmeduni.ac.at/o:2193 Rapid and biased evolution of canalization during adaptive divergence revealed by dominance in gene expression variability during Arctic charr early development Horta-Lacueva, Quentin Jean-Baptiste Quentin Jean-Baptiste Horta-Lacueva 0000-0001-9656-1731 University of Iceland / Lund University Kapralova, Kalina Hristova Kalina Hristova Kapralova 0000-0002-5571-0160 University of Iceland Hallgrímsson, Benedikt Benedikt Hallgrímsson 0000-0002-7192-9103 University of Calgary Jónsson, Zophonías Oddur Zophonías Oddur Jónsson 0000-0001-5798-9647 University of Iceland Thorholludottir, Dagny A. V. Dagny A. V. Thorholludottir University of Veterinary Medicine Vienna / University of Iceland Nature Portfolio text eng Adaptive evolution may be influenced by canalization, the buffering of developmental processes from environmental and genetic perturbations, but how this occurs is poorly understood. Here, we explore how gene expression variability evolves in diverging and hybridizing populations, by focusing on the Arctic charr (Salvelinus alpinus) of Thingvallavatn, a classic case of divergence between feeding habitats. We report distinct profiles of gene expression variance for both coding RNAs and microRNAs between the offspring of two contrasting morphs (benthic/limnetic) and their hybrids reared in common conditions and sampled at two key points of cranial development. Gene expression variance in the hybrids is substantially affected by maternal effects, and many genes show biased expression variance toward the limnetic morph. This suggests that canalization, as inferred by gene expression variance, can rapidly diverge in sympatry through multiple gene pathways, which are associated with dominance patterns possibly biasing evolutionary trajectories and mitigating the effects of hybridization on adaptive evolution. Salvelinus-Alpinus; Morphological Variation; Fluctuating Asymmetry; Phenotypic Plasticity; Directional Selection; Stability; Population; Thingvallavatn; Pleiotropy; Ontogeny http://creativecommons.org/licenses/by/4.0/ https://phaidra.vetmeduni.ac.at/api/object/o:2193/download 10.1038/s42003-023-05264-5 https://phaidra.vetmeduni.ac.at/o:605 application/pdf Communications Biology 6(1) (2023) Communications Biology 6 1 1.79 MB 2023