Table 2 Newborn IgM VH regions predominantly use only the DH1 gene. The aligned IgM cDNA clones from Figure 2 were analyzed for DH gene usage by comparison to the horn shark genomic DH genes (Accession #X13447 [33]). The DH gene portion that exactly matches the horn shark is underlined and italicized nucleotides indicate non-templated GC nucleotide additions. Clones that could not be conclusively identified as either DH gene are indicated by (?). CDR3 identical in sequence to both DH genes are indicated by (D1/D2). Clones 22E and 36E excluded due their non-productive rearrangement.

GTGGGTAC TGGT

VGTG

AGCCACGGGGAGAGGAGCCAGAGCCACTGTGGCTATCTT (D1/D2)

SHGERSQSHCGYL

CAACTACA GGACTGGG ATGATCCA

QLQDWDDP

GACGACAGTGGG GGGTCTCCC

ATACTGGGT CCGACCTACTAT

DDSGGSP

ILGPTYY

GACGGAGTGATA CTGGG A

DGVILG

GACTACAGTG

CCTGGG ATACCATTGGT

DYS

AWDTIG

ACAACAAACTCTCTGGGT

TTNSLG

ACAATA TTCGGT

TIFG

ACTACTTTCGGT (?)

TTFG

AGGGGGGGGGA CTGGG GTAGGTTCGCT

RGGDWGRFA

AAGACCCACC TACAG TCTATA

CTGGG GTCCTTCGCT

KTHLQSI

LGSFA

GCCTC AGTGG AGCGGGAATTCGCT

ASVEREFA

GATGGTG GGGT AGGGGAATTCGCT (D1/D2)

DGGVGEFA

AGCAGTGGGT ACGAATTCGCT

SSGYEFA

GTCAGGGGGGAGGCGGTT (?)

VRGEAV

GACACAGT AGGGGGAGCG

DTVGGA

ACAGAAAGTGGG

GGGGG TGGG GCCGGT

TESG

GGGAG

ACAGATATCAGTGG CCGGGTAGCCGGT

TDISGRVAG

ACAAGACGCATG AGTGGG TATGAATACT

TGGG CGGCCACTCCGGT

TRRMSGYEY

LGGHSG

ACCCGATCTACGGCGCCCCTTTGT (?)

TRSTAPLC

ACAGGGGGGTAC TTGGGT (D1/D2)

TLG

ACAGTGGG CGGT

TVGG

ACTACAGTGGGT

TTVG

ACAGACAGTGGG

TDSG