Ferret preproendothelin-2 (PPET2) cDNA was cloned from intestinal tissue by reverse transcription-polymerase chain reaction (RT-PCR) in conjunction with 5'- and 3'-rapid amplification of cDNA ends (RACE). The cDNA comprises 1230 bp, excluding the poly(A) tail, and has 534 bp of open reading frame encoding a putative polypeptide of 178 residues, in which a 21-amino acid mature endothelin-2 (ET2) peptide as well as a 24-amino acid putative signal peptide and a 16-amino acid ET2-like peptide were found. The homology of the full-length cDNA sequence of ferret with those of horse, human, mouse, or rat was 75.6, 71.6, 65.4 or 65.1%, respectively, and the homology of the coding region was 85.1, 81.6, 78.1 or 75.3%, respectively. Phylogenetic analysis among ferret, horse, human, mouse, rat and dog showed that ferret has a closer relationship to dog than to the other mammals.