The Prx1 limb enhancers: targeted gene expression in developing zebrafish pectoral fins.

Limbs represent an excellent model to study the induction, growth, and patterning of several organs. A breakthrough to study gene function in various tissues has been the characterization of regulatory elements that allow tissue-specific interference of gene function. The mouse Prx1 promoter has been used to generate limb-specific mutants and overexpress genes in tetrapod limbs. Although zebrafish possess advantages that favor their use to study limb morphogenesis, there is no driver described suitable for specifically interfering with gene function in developing fins. We report the generation of zebrafish lines that express enhanced green fluorescent protein (EGFP) driven by the mouse Prx1 enhancer in developing pectoral fins. We also describe the expression pattern of the zebrafish prrx1 genes and identify three conserved non-coding elements (CNEs) that we use to generate fin-specific EGFP reporter lines. Finally, we show that the mouse and zebrafish regulatory elements may be used to modify gene function in pectoral fins.