Figure 1.

Activity-dependent K⁺ channel gene expression in the VNO. a, Schematic diagram illustrating the experimental strategy used for pheromone exposure (left) and stimulus deprivation (right) of singly housed C57BL/6 mice. b, Differentially expressed K⁺ channel genes in the VNO. Analysis (see Materials and Methods) of seven microarrays (4 stimulated/3 deprived) reveals both consistent expression (7 of 7 arrays) and significant (p ≤ 0.029) regulation of the following genes: Kcnh2 (ERG1; up), Kcna5 (up), Kcne3 (MiRP2; down), Kcna2 (down), and Kcnj16 (down). For each gene, RefSeq accession numbers, Affymetrix identifications, and average fold changes (mean ± SEM; 12 independent comparisons) are specified. c, Vomeronasal transcripts of both ERG1 isoforms (ERG1a and ERG1b), ERG3, and MiRP2 are detected by RT-PCR and sequencing. Specificity is confirmed by positive [cerebellum; heart (ERG1a, ERG1b, MiRP2)] and negative [heart (ERG3); LNCaP cells] controls. No PCR product is amplified when reverse transcription is omitted (control). d, e, Representative immunoblotting experiments illustrating the regulation of ERG1 and MiRP2 protein expression. Individual blot panels (d or e) correspond to the same SDS-polyacrylamide gel, respectively. d, Western blot analysis demonstrating increased levels of vomeronasal ERG1a/1b expression in stimulated mice versus deprived mice. Blots (n = 4) were additionally probed for β-tubulin and GAPDH as loading controls. e, Western blots (n = 3) probed with MiRP2 antibody reveal downregulated protein expression in stimulated animals.