Comparative Mapping and Genomic Annotation of the Bovine Oncosuppressor Gene <i>WWOX</i>

<i>WWOX</i> (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 <i>WWOX</i> in the bovine genome. First, we sequenced cDNA from various tissues and obtained evidence in support of a 9-exon structure for the gene, similar to the human gene. 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 an issue related to exon 9, which is not included in the genomic annotation of the gene in the Entrez database. Finally, BACs spanning <i>WWOX</i> were used as FISH probes to obtain comparative mapping of the gene in <i>Bos taurus</i>, <i>Bubalus bubalis</i>, <i>Ovis aries</i> and <i>Capra hircus</i> to BTA18q12.1, BBU18q13, OAR14q12.1 and CHI18q12.1, respectively. Our data show that the chromosomal location of <i>WWOX</i> is conserved between man and 4 major domesticated species. Moreover, the annotation of the bovine gene also suggests a highly conserved genomic arrangement, including number and size of introns.