title: A hypomorphic allele of aryl hydrocarbon receptor-associated protein-9 produces a phenocopy of the AHR-null mouse.
abstract: The aryl hydrocarbon receptor-associated protein-9 (ARA9) is a chaperone of the aryl hydrocarbon receptor (AHR). The AHR has been shown to play a late developmental role in the normal closure of a fetal hepatovascular shunt known as the ductus venosus (DV). Given that Ara9-null mice display early embryonic lethality, we generated a hypomorphic Ara9 allele (designated Ara9(fxneo)) that displays reduced ARA9 protein expression. In an effort to demonstrate the role of ARA9 protein in AHR-mediated DV closure, we used combinations of Ara9 wild-type [Ara9(+/+)], null [Ara9(-/-)], and hypomorphic [Ara9(fxneo/fxneo)] alleles to produce mice with a graded expression of the ARA9 protein. Liver perfusion studies demonstrated that although none of the Ara9(+/+) mice displayed a patent DV, the shunt was observed in 10% of the Ara9(+/fxneo) mice, 55% of the Ara9(+/-) mice, and 83% of the Ara9(fxneo/fxneo) mice. That expression level of ARA9 correlates with the frequency of a phenocopy of the Ahr-null allele supports the conclusion that the ARA9 protein is essential for AHR signaling during development.
authors.affiliation: McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI 53706, USA.
authors.forename: Bernice C
authors.initials: BC
authors.lastname: Lin
authors.forename: Linh P
authors.initials: LP
authors.lastname: Nguyen
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Walisser
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Bradfield
mesh_terms: D000483:Alleles; D000818:Animals; D015139:Blotting, Southern; D015153:Blotting, Western; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D009929:Organ Size; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics*; D014680:Veins / Q000002:abnormalities
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D018336:Receptors, Aryl Hydrocarbon; C103265:aryl hydrocarbon receptor-interacting protein