Generation and characterization of Tph2-/-mice. (A) Top: Schematic diagram of the genomic locus for the Tph2 gene. Middle: the gene-targeting construct. Bottom: targeted Tph2 allele. The black box denotes the coding exon. (B) Southern blot analysis of wild-type (Tph2+/+) and targeted ES clone (Tph2f/+). Predicted size of the genomic fragments was detected. (C) Growing curve of male and female Tph2+/+ and Tph2-/- mice from P1 to 8-week. (D) Anti-5-HT immunoreactivity in the dorsal raphe (left), spinal cord (middle) and intestine (right) of Tph2+/+ mice (upper row) and Tph2-/- mice (lower row). (E) Images (left) and quantified data (right) to show in situ hybridization of Tph2, Sert, AADC and VMAT2 in Tph2+/+ and Tph2-/- mice. Error bars represent SEM. n = 5. Scale bars, 100 μm.