A post-embryonic specific and ecologically selective network underlies metamorphic remodelling in teleosts

A post-embryonic developmental gene network is conserved across five divergent teleost fish despite 200 million years of divergence, including thyroid hormone responsiveness.

• Why it matters: Post-embryonic transitions like metamorphosis drive much animal diversity, but whether they share conserved genetic architecture and how it evolves is unclear.
• What they did: Using a comparative framework with multiple data modalities, the study characterizes post-embryonic development in five teleost species and an outgroup spotted gar, integrating gene network conservation, expression/tissue specificity, thyroid hormone treatment responsiveness, and gene family copy number variation.
• The result: The network shows conserved core and post-embryonic remodelling modules, with gene family copy number turnover linked to macroevolutionary variation in ecological and morphological traits, supported by multi-species tissue expression and zebrafish perturbation phenotypes.