Highly conserved sequences in Ntng1 loci and strategy for analyzing cis -regulatory elements in transgenic mice. (A) Comparative genomic analysis of the mouse Ntng1-BAC clone (mouse Dec. 2011 [GRCm38/mm10] assembly; chr3:110,101,082 -110,318,433) by the VISTA genome browser. Percent nucleotide identities between mouse and human DNA sequences were plotted as a function of the position along the mouse sequence. Peaks of evolutionary-conserved exons of Ntng1 and neighboring genes are shaded blue. Aligned regions with more than 70% identity over 100 bases are shaded pink. (B) Schematic diagrams of the Ntng1 deletion series. The Ntng1-BAC sequences are divided into 6 segments (I–VI indicated in colored boxes) along with ECR distribution. Genomic organizations of the mouse Ntng1 and neighbor gene loci are indicated. Short vertical lines indicate positions of exons and arrowheads indicate transcriptional directions. Broken and solid lines represent deleted and preserved regions in the BAC constructs, respectively. Blue boxes on the lines represent the reporter LacZ cassette inserted in each BAC construct. Note that the reporter LacZ cassette, ECRs, and minimal promoter sequences are not represented in accurate scales.