A novel 12- and 15-lipoxygenase related gene was isolated from a mouse strain 129 genomic phage library in a screen with a human 15-lipoxygenase cDNA probe. The complete genomic sequence revealed 14 exons and 13 introns covering 7.3 kb of DNA. The splice junctions were verified from the cDNA sequences of a series of overlapping RT-PCR products. This novel mouse lipoxygenase gene was found to contain an open reading frame encoding 662 amino acids. The cDNA sequence is 68% identical to the mouse leukocyte type 12-lipoxygenase and 65% identical to the mouse platelet type 12-lipoxygenase cDNA. Nucleotide identities to the human 15-lipoxygenase cDNA and the human platelet type 12-lipoxygenase cDNA are 70% and 67%, respectively. The deduced amino acid sequence is 60% identical to the mouse platelet and leukocyte type 12-lipoxygenase sequences and the human 15- and 12-lipoxygenase sequences. This novel mouse lipoxygenase gene was found to be transcribed predominantly in epidermal tissue and named Aloxe.