Targeted disruption of the mouse apolipoprotein
A-II gene. (A) The mouse apo A-II gene locus. Exons 1–4 are
represented by black boxes. (B) The gene targeting
construction. The neomycin resistant gene (neo) cassette
replaced the entire mouse apo A-II gene, including the promoter region.
(C) The gene locus after DNA homologous recombination. The
12-kb EcoRI fragment of the endogenous locus
was modified to 3.8 kb in the targeted locus. RI, EcoRI;
B, BamHI; Sp, SpeI; Sph,
SphI; K, KpnI; Xb, XbaI;
S, SalI, Bg, BglII.