0012-160628412005Aug01Dev BiolLoss of Gbx2 results in neural crest cell patterning and pharyngeal arch artery defects in the mouse embryo.233245233-45Several syndromes characterized by defects in cardiovascular and craniofacial development are associated with a hemizygous deletion of chromosome 22q11 in humans and involve defects in pharyngeal arch and neural crest cell development. Recent efforts have focused on identifying 22q11 deletion syndrome modifying loci. In this study, we show that mouse embryos deficient for Gbx2 display aberrant neural crest cell patterning and defects in pharyngeal arch-derived structures. Gbx2(-/-) embryos exhibit cardiovascular defects associated with aberrant development of the fourth pharyngeal arch arteries including interrupted aortic arch type B, right aortic arch, and retroesophageal right subclavian artery. Other developmental abnormalities include overriding aorta, ventricular septal defects, cranial nerve, and craniofacial skeletal patterning defects. Recently, Fgf8 has been proposed as a candidate modifier for 22q11 deletion syndromes. Here, we demonstrate that Fgf8 and Gbx2 expression overlaps in regions of the developing pharyngeal arches and that they interact genetically during pharyngeal arch and cardiovascular development.ByrdNoah ANADepartment of Pediatrics and Cell Biology, Neonatal Perinatal Research Institute, Genome Science Research Building II, Box 3471, Duke University Medical Center, Durham, NC 27710, USA.MeyersErik NENengHL77044-01HLNHLBI NIH HHSUnited StatesP01 HD39948HDNICHD NIH HHSUnited StatesR01 HD42803HDNICHD NIH HHSUnited StatesComparative StudyJournal ArticleResearch Support, N.I.H., ExtramuralResearch Support, U.S. Gov't, P.H.S.