Comparative mapping and genomic annotation of the bovine oncosuppressor WWOX gene

WWOX (WW domain-containing oxidoreductase) is the gene mapping at FRA16D, HSA16q23.1, the second most active common fragile site in the human genome. In this study we characterized at a detailed molecular level WWOX in the bovine genome. First we sequenced the cDNA from various tissues and obtained evidence in support of a nine exons structure for the gene, as it is in man. Then, we recovered BACs using exon tags and annotated the gene to a >1 Mb genomic region of BTA18 using the Btau 4.0 genome assembly as a reference, thus resolving a issue related to exon 9, which is not included in the genomic annotation of the gene in the Entrez database. Finally, BACs spanning WWOX were used as FISH probes to obtain a comparative mapping of the gene in Bos taurus, Bubalus bubalis, Ovis aries and Capra hircus to BTA18q12.1, BBU18q13, OAR14q12.1 and CHI18q12.1, respectively. Our data show that the chromosomal localization of WWOX is conserved between man and four major domesticated species. Moreover, the annotation of the bovine gene suggests also a highly conserved genomic arrangement, including number and size of introns.