Figure 1.

Schematic representation of plasmid DNA γ1NANP. This plasmid carries a chimeric H chain gene in which a productively rearranged murine variable region gene is joined to a human γ1 constant region gene. The variable region gene was modified in the CDR3 by introduction of the nucleotide sequence coding for three Asn-Ala-Asn-Pro repeats to serve as a specific molecular marker (32). In this plasmid, the promoter and enhancer elements are those constitutively existing in Ig H chain genes. Neo^r, neomycin resistance gene; Amp^r, ampicillin resistance gene; PR, promoter; EN, enhancer; C_H, heavy chain C region; V_H, heavy chain variable region; FR, framework region.