Characterization of contractile vascular responses in Bbs2−/−, Bbs6−/−, and wild-type control mice. Contractions were induced in aortic rings from Bbs2−/− and Bbs6−/− mice and wild-type littermate controls using receptor-dependent agonists including serotonin (5-HT; A), endothelin-1 (ET-1; B), and prostaglandin F2α (PGF2α; D) or the receptor-independent constrictor potassium chloride (KCl; C). *P < 0.05 vs. wild-type mice, †P < 0.05 vs. wild-type and Bbs2−/− mice (n ≥ 8).