Fig. 1. Generation and characterization of PITPα-deficient mice.

A, targeted replacement of the wild-type PITPα locus with PITPαΔ::neo*. Organization of the targeting vector is shown. Probe 1 represents a 500-bp DNA fragment that resides outside the bounds of the targeting vector and is employed for diagnosis of targeting events. Exons 7–10 of the PITPα structural gene are indicated as closed bars and are numbered accordingly. Restriction enzyme sites: E, EcoRI; X, XbaI; K, KpnI; S, SacI. B, OmniBank^™ gene trap library at the PITPα locus. Retroviral construct VICTR20 is depicted (20). The PITPα::neo/puro mutation represents integration of VICTR20 between PITPα exons 7 and 8 and truncates PITPα after residue 162. The abbreviations used are as follows: LTR, long terminal repeat; PGK, phosphoglycerate kinase-1 promoter; puro, puromycin N-acetyltransferase gene; SD, spice donor sequence; SA, splice acceptor sequence; IRES, internal ribosome entry site; geo, galactosidase/neomycin phosphotransferase fusion gene; pA, polyadenylation sequence. C, distribution of PITPα genotypes in the F1. The number of live births obtained for each PITPα genotype (indicated at top), from a dedicated set of 408 F1 progeny of PITPα^−/+ intercrosses, is given above the corresponding bar. D, confirmation of viable PITPα^−/− progeny. Upper left panel, diagnostic PCR profiles of PITPα^+/+, PITPα^−/+, and PITPα^−/− progeny derived from a PITPα+/− intercross. Upper right panel, total brain lysates (20 μg) harvested from each of five sibling pups (genotypes indicated) derived from a PITPα+/− intercross were resolved by SDS-PAGE and developed by immunoblotting with PITPα-specific antibodies. Lower panel, immunoblot of PITPβ in brain lysates (20 μg) from neonates of indicated genotype.