A GFP tag is introduced at the ATG of the mud open reading frame in the CH322-147E14 BAC genomic clone. This BAC clone contains ~19.5 kb of X chromosome genomic region including ~3.3 kb upstream of the mud mRNA 5' and 5.4 kb downstream of the mud 3' mRNA and thus most of the coding regions of genes proximal and distal to mud locus. The region encoding the putative transmembrane domain (TM, amino acids 2,456-2,499) of mud is deleted.