section_path: Muscle fiber type evolution/Genetic conservation versus functional conservation
section_name: Genetic conservation versus functional conservation
paragraph_text: Genetic conservation versus functional conservation
  
  Across species, certain gene sequences have been preserved, but do not always have the same functional purpose. Within the zebrafish embryo, the Prdm1 gene down-regulates the formation of new slow twitch fibers through direct and indirect mechanisms such as Sox6 (indirect). In mice, the Prdm1 gene is present but does not control slow muscle genes in mice through Sox6.