Simmons D L, Kasper C B
J Biol Chem. 1983 Aug 25;258(16):9585-8.
Southern blot analysis suggests that multiple sequences homologous to a phenobarbital-inducible cytochrome P-450 cDNA are present in the rat and mouse genomes. A cDNA (pP-450b-5) to a major phenobarbital-inducible cytochrome P-450 mRNA species in the rat detected 6 polymorphic DNA fragments when hybridized to DNA from C57BL/6J and DBA/2J mice restricted with endonucleases EcoRI, BamHI, and PvuII. Using the BXD recombinant inbred strains, five of these polymorphisms were mapped to the Coh (coumarin hydroxylase) locus on chromosome 7 of the mouse. The Coh locus has previously been shown to code for a phenobarbital-inducible enzyme, believed to be a cytochrome P-450, which catalyzes the conversion of coumarin to 7-hydroxycoumarin (umbelliferone). The DNA polymorphisms appear to reflect changes in either cytochrome P-450 genes or pseudogenes that are very closely linked to the gene responsible for differential coumarin hydroxylase in mice or it may represent a change(s) in the Coh gene itself. The region of the Coh locus on chromosome 7 may be the site of a cluster of cytochrome P-450 genes.
Southern印迹分析表明，大鼠和小鼠基因组中存在多个与苯巴比妥诱导型细胞色素P-450 cDNA同源的序列。用一种针对大鼠主要苯巴比妥诱导型细胞色素P-450 mRNA的cDNA（pP-450b-5）与经内切酶EcoRI、BamHI和PvuII酶切的C57BL/6J和DBA/2J小鼠的DNA杂交时，检测到6个多态性DNA片段。利用BXD重组近交系，其中5个多态性被定位到小鼠7号染色体上的Coh（香豆素羟化酶）位点。先前已证明Coh位点编码一种苯巴比妥诱导型酶，据信是一种细胞色素P-450，它催化香豆素转化为7-羟基香豆素（伞形酮）。DNA多态性似乎反映了细胞色素P-450基因或假基因的变化，这些基因与小鼠中负责香豆素羟化酶差异的基因紧密连锁，或者它可能代表Coh基因本身的变化。7号染色体上Coh位点的区域可能是细胞色素P-450基因簇的位点。
