Section Immunostaining for Protein Expression and Cell Proliferation Studies of Regenerating Fins

Adult zebrafishZebrafish finsFins fully regenerate after resection, providing a highly accessible and remarkable vertebrate model of organ regeneration. FinFins injury triggers wound epidermis formation and the dedifferentiation of injury-adjacent mature cells to establish an organized blastema of progenitor cells. Balanced cell proliferationCell proliferation and redifferentiation along with cell movements then progressively reestablish patterned tissues and restore the finFins to its original size and shape. A mechanistic understanding of these coordinated cell behaviorsBehaviors and transitions requires direct knowledge of proteins in their physiological context, including expression, subcellular localization, and activity. Antibody-based staining of sectioned finsFins facilitates such high-resolution analyses of specific, native proteins. Therefore, such methods are mainstays of comprehensive, hypothesis-driven fin regenerationFin regeneration studies. However, section immunostaining requires labor-intensive, empirical optimization. Here, we present detailed, multistep procedures for antibodyAntibodies staining and co-detecting proliferating cells using paraffin and frozen finFins sections. We include suggestions to avoid common pitfalls and to streamline the development of optimized, validated protocols for new and challenging antibodiesAntibodies.