FIGURE 1.
Generation and characterization of CerS2 null mice. A, CerS2 null mice were created by crossing CerS2GT/+ mice generated from a gene trap embryonic stem cell line (stock number 013236-UCD, Mutant Mouse Regional Resource Center). The upper panel shows the Rosafary gene trap retroviral vector used to generate CerS2 gene trap embryonic stem cells (35). A splice acceptor (SA) is located upstream to a β-geo gene (neo resistance + lacZ genes), which is followed by a polyadenylation sequence (pA). A selectable marker for hygromycin (hyg) resistance is expressed under the phosphoglycerate kinase (PGK) promoter, followed by a splice donor (SD) sequence, which is within two frt sites that are recognized by Flp recombinase. Elements of this vector are marked as gray boxes. The vector was inserted between exons 1 and 2 of the CerS2 gene (dashed lines). Exons are marked as black boxes, and translational start and stop sites are shown as arrows. A spliced transcript of the WT locus is also shown. The lower panel shows the integration of the retroviral vector into the CerS2 gene, leading to generation of two transcripts. Transcript 1 is generated by splicing exon 1 of CerS2 (5′-untranslated region) into the Rosafary splice acceptor, resulting in expression of lacZ under the CerS2 promoter. The second transcript is driven by the PGK promoter of the hygromycin gene, which is spliced into the second exon of CerS2. B, CerS2 null mice do not express full-length transcript 2, demonstrated using primers that amplify the full-length CerS2 transcript. C, weight of CerS2 null mice. *, p < 0.01; n = 5.