Alignment of deduced amino acid sequences of opossum VpreB3 with mouse VpreB1, 2, and 3, human VpreB1 and 2, rabbit VpreB3, and chicken VpreB3. Leader peptide, and the regions that correspond to FR1 through 3 and CDR1 and 2 in Ig V domains are indicated above the alignment. Residues identical to the opossum sequence are indicated by dashes; dots indicate insertions necessary for generating the alignment. Conserved cysteines are shaded while the conserved HXAC motif is highlighted in black. The mouse VpreB1, VpreB2, and VpreB3 sequences that were used to perform an in silico search of the opossum whole genome using the BLAST algorithm were Genbank accession nos. NM_016982, BC141459, and NM_009514). To complete the partial opossum VpreB gene identified, primers were designed to flank a 329 bp gap at the 5’ end of the gene (5’-AGGAGGGCCTTCTCAGGA and 5’-GCTCCTGCTCCTCTTCATTG) and a product that covered the gap was cloned and sequenced.