Figure 7.

Lbhd2-CreERT2 line achieves MC-specific labeling in the OB even in adulthood. A, Constructs for CRISPR/Cas9-mediated knock-in line. IRES-CreERT2 cassette was targeted to a region immediately following the stop codon of the Lbhd2 gene. B, Schematic of the tamoxifen injection protocol: tamoxifen was injected intraperitoneally at P21, and the recombination pattern in the OB was examined 3 weeks later. Cohorts of mice received injection for either 1 or 3 d at 80 mg/kg per day. C, Example recombination patterns. From left: Tbx21-Cre::Ai14, Ra13-Cre::Ai14, Lbhd2-CreERT2::Ai14 (one injection) and Lbhd2-CreERT2::Ai14 (three injections). Scale bar, 100 µm. D, Summary of labeled structures at P42 for the corresponding mouse lines, showing the proportion of cells in the MCL relative to all labeled cells (left), comparison of labeled dendrites in the superficial versus deep portions of the EPL (middle), and density of labeled somata in the MCL (right). E, Comparison of labeling patterns between Tbx21-Cre::Ai14, Ra13-Cre::Ai14, and Lbhd2-CreERT2::Ai14 lines. Left, Labeled cells in the MCL as a percentage of total number of labeled cells. Middle, tdTomato signal density in the upper half of EPL subtracted by the signal density in the lower half of EPL. Right, Number of labeled cells detected per mm of MCL. N = 3 mice per transgenic line for all plots. Data are mean ± SEM. Statistical significance: *p = 0.05; **p = 0.01. For details, see Experimental design and statistical analysis.