Targeted manipulation of the GluN2A gene. (A) Top: the wild-type GluN2A gene locus, Middle: the targeting vector containing the WT and mutant exon 10, the artificial introns, and three loxP sequences. Bottom: the floxed GluN2A gene. The open horizontal bar represents the probe used for Southern blot analyses. Relevant restriction sites are indicated: B, Bam HI; H, Hin dIII; HII, Hin cII; Sm, Sma I. (B) The artificial exon–intron sequences are described. The loxP sequences are shown in red. WT exon 10 and mutant exon 10 are enclosed in orange and green boxes, respectively. The fruit fly tra gene intron 1 sequences (including Sxl-binding splicing acceptor) and the splice donor and acceptor sites of the mouse β-globin intron are shown in violet and blue, respectively. The adenosine enclosed by a blue box represents a branch site. (C) Schematic representation of the conditional amino acid substitution of the GluN2A gene.