The regenerating caudal fin of an adult zebrafish is a great model system to study gene regulation and function. However, manipulation of essential genes in adult fins can be challenging. In this brief report, we suggest that a fibroblast cell line AB9, isolated from regenerating caudal fins of adult zebrafish, can be used to perform pilot studies for gene regulation. We also provide standardized protocols for morpholino and drug treatment of AB9 cells. Our findings suggest that the AB9 cell line is an easily manipulated system that expresses key regulators of the Cx43 dependent growth and patterning pathway, identified from studies in the regenerating fin. We also provide evidence that expression and function of proteins can be easily manipulated, either through targeted morpholino knockdown or by pharmacological inhibition.