Sequences of mouse immunoglobulin light chain genes before and after somatic changes

Murine lambda gene rearrangements: the stochastic model prevails over the ordered model.

“…The VXx probe was the 0.3 kb HindI-BamHI fragment from the VXx region of a VXx CX2 cDNA clone (Sanchez et al, 1987b). The CX1 probe was the 1.8 kb BamHI-BgII fragment from the CX1 region (Bernard et al, 1978). The VXx CX2 probe was the 0.6 kb BamHI-BamHI fragment from the CX2 region of a VXx CX2 cDNA clone (Sanchez et al, 1987b).…”

“…Four different chains can be obtained from the X gene segments ordered on chromosome 16 as follows: VX2 VXx JX2 CX2 VX1 JX3 CX3 JX1 CX1 Carson et al, 1989) to identify and differentiate each X subtype rearrangement (see Figure 1). The VX1 probe hybridizes both with VXl and VX2 gene segments (>93% identity at the nucleotide level), the VXx probe hybridizes specifically with the VXx gene segment, the VXx CX2 probe hybridizes both with the CX2 and CX3 gene segments (96% identity at the nucleotide level) and with VXx gene segment, and the CX1 probe hybridizes specifically with the CXI gene segment (Bernard et al, 1978;Selsing et al, 1982;Sanchez et al, 1987b). To identify joins involving VX1 and VX2 segments, we hybridized the VX1 probe to electrophoresed Bgll digested BALB/c DNA ( Figure 2A, lanes Cl to 1E72 and 3E123), corresponding respectively to the VX1 JX1, VX2 JX2 and VX1 JX3 rearrangements (see Figure 1).…”

Evidence indicating independent assortment of framework and complementarity-determining segments of the variable regions of rabbit light chains. Delineation of a possible J minigene.

“…Although the clones from 12-d-old mouse embryo DNA indicate that nucleotides coding for amino acids 1-05 occur as a contiguous segment (14,17,18,26), the evidence for assortment, by recombination with or insertion into nucleotides coding for FR segments, of nucleotides coding for CDR segments suggests that this minigene mechanism in addition to diversity generated by the joining of residues 1-95 to the J minigene is fundamental to the generation of diversity. It is important to distinguish between the generation of diversity and the generation of complementarity differences responsible for antibody specificity, e.g., for noncovalent binding of an antigenic determinant in the antibody-combining site.…”

“…If the differences involved deletions or insertions or when a three base change was involved this is indicated by a dagger (t"). To define a potential J segment and because of length variations in CDR3, the last two residues of CDR3 in each sequence were renumbered as 97E and 97F and assorted with FR4 as a J segment (97E, 97F-107) comparable with what had been observed in the mouse by assortment (24) and by nucleic acid sequencing of clones (26). In rabbit 2717 residue 106A had been misaligned and was made residue 107.…”

“…They proposed that some diversity of antibodycombining sites could be generated by V-J joining because residue 96 is highly hypervariable (1, 2, 25). Because adult myeloma VL DNA clones code for a contiguous stretch of amino acids 1-107 (or 108) (26), the joining oftheJ minigene to the DNA of the region coding for amino acids 1-95 has taken place during embryogenesis.…”