HUMAN RETINA-SPECIFIC AMINE OXIDASE - GENOMIC STRUCTURE OF THE GENE (AOC2), ALTERNATIVELY SPLICED VARIANT, AND MESSENGER-RNA EXPRESSION IN RETINA

Previously, we reported the isolation of cDNA for human retina-specifi c amine oxidase (RAO) and the expression of RAO exclusively in retina. Bacterial artificial chromosome clones containing the human RAO gene (AOC2) were mapped to human chromosome 1.7q21. (Imamura et al., 1997, Genomics 40: 277-283). Here, we report the complete genomic structure of the RAO gene, including 5' flanking sequence, and mRNA expression i n retina. The human RAO gene spans 6 kb and is composed of four exons corresponding to the amino acid sequence 1-530, 530-598, 598-641, and 642-729 separated by three introns of 3000, 310, and 351 bp. Screening of a human retina cDNA library revealed the existence of an alternati vely spliced cDNA variant with an additional 81 bp at the end of exon 2. The sizes of exons and the locations of exon/intron boundaries in t he human RAO gene showed remarkable similarity to those of the human k idney diamine oxidase gene (AOC1). In situ hybridization revealed that mRNA coding for RAO is expressed preferentially in the ganglion cell layer of the mouse retina. We designed four sets of PCR primers to amp lify four exons, which will be valuable for analyzing mutations in pat ients with ocular diseases affecting the retinal ganglion cell layer. (C) 1998 Academic Press.