| abstract |
A rodent whose genome comprises: (a) the human IgH VDJ region inserted upstream of the rodent host constant region; and (b) one or more human Ig κ light chain V regions and one or more human Ig κ light chain J regions upstream of the κ constant region of the rodent host; wherein the rodent is capable of producing a repertoire of chimeric antibodies having a rodent constant region and a human variable region; wherein the genome comprises the V, D (heavy chain only) and J genes at the heavy chain locus and at one light chain locus, but not at both light chain loci, and the genome of rodent is homozygous at both immunoglobulin loci; wherein the human DNA insertion is made between the rodent constant region and the rodent's last 3' J region, wherein the genome can be obtained by i. inserting DNA that forms an initiation cassette into the genome of a cell; ii. insertion of a first DNA fragment at the insertion site, wherein the first DNA fragment comprises a first portion of human VDJ region DNA and a first vector portion containing a first selection marker or generating a marker selection after insertion; iii. deletion of part of the vector DNA; IV. insertion of a second DNA fragment into the vector portion of the first DNA fragment, the second DNA fragment contains a second human VDJ region DNA portion and a second vector portion, the second vector portion contains a second selection marker, or generates a second selection marker upon insertion; v. deleting any vector DNA to allow the first and second human DNA fragments to form a contiguous sequence; and I saw. repeating the steps of inserting a portion of human VDJ DNA and deleting the vector DNA, as necessary, to produce a cell with the entire human VDJ region, in which one or more insertion events use recombination site specific. |