Conserved motifs of regulatory elements in the core promoter regions (about 500 bps) of cattle (GenBank No. EU148609), rat (GenBank No. AF087944), mouse (GenBank No. X13987), human (GenBank No. U00699) and pig (GenBank No. DQ079063). + indicates the presence of a motif and • its absence. ♣ indicates motifs that are conserved in all five species and * in four species including cattle. A maximum of three base pair mismatches was allowed.