title: Generation of 'humanized' hCYP1A1_1A2_Cyp1a1/1a2(-/-) mouse line.
abstract: Human/rodent CYP1A1 and CYP1A2 orthologs are well known to exhibit species-specific differences in substrate preferences and rates of metabolism. This lab previously characterized a BAC-transgenic mouse carrying the human CYP1A1_CYP1A2 locus; in this line, human dioxin-inducible CYP1A1 and basal vs dioxin-inducible CYP1A2 have been shown to be expressed normally (with regard to mRNAs, proteins and three enzyme activities) in every one of nine mouse tissues studied. The mouse Cyp1a1 and Cyp1a2 genes are oriented head-to-head and share a bidirectional promoter region of 13,954 bp. Using Cre recombinase and loxP sites inserted 3' of the stop codons of both genes, we show here a successful interchromosomal excision of 26,173 bp that ablated both genes on the same allele. The Cyp1a1/1a2(-) double-knockout allele was bred with the "humanized" line; the final product is the hCYP1A1_1A2_Cyp1a1/1a2(-/-) line on a theoretically >99.8% C57BL/6J genetic background-having both human genes replacing the mouse orthologs. This line will be valuable for human risk assessment studies involving any environmental toxicant or drug that is a substrate for CYP1A1 or CYP1A2.
authors.affiliation: Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, PO Box 670056, Cincinnati, OH 45267-0056, USA.
authors.forename: Nadine
authors.initials: N
authors.lastname: Dragin
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Uno
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Dalton
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Nebert
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000494:pharmacology; D018929:Cell Culture Techniques; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured; D019363:Cytochrome P-450 CYP1A1 / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D019388:Cytochrome P-450 CYP1A2 / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D005838:Genotype; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D001564:Benzo(a)pyrene; D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2