A 979bp fragment containing the presumed promoter region and 5' UTR of the cul-3 testis isoform is fused upstream of the complete coding region of the cul-3 soma isoform (2336bp fragment from cDNA clone SD20020) followed by a 345bp fragment from the 3' UTR of the cul-3 testis isoform (from cDNA clone AT07783).