Mapping of genes for cytochromes P-450b, P-450e, P-450g, and P-450h in the rat. Demonstration of two gene clusters with P450-b,e localized on chromosome 1.

Abstract

Inbred ACI, WF, and RCS rats having characteristic markers for albino (c), hemoglobin beta-chain (Hbb), and pink-eyed dilution (p) on chromosome 1 and expressing variants for hepatic cytochromes P-450b, P-450e, P-450g, and P-450h were used in genetic mapping studies for these hemoproteins. The results of WF X (ACI X WF)F1 and RCS X (WF X RCS)F1 backcrosses revealed the existence of two gene clusters designated the P450-b,e and P450-g,h loci. The linkage map P450-b,e-p-c-Hbb on rat chromosome 1 was demonstrated and found to be congruent with Coh(P450-b,e)-p-c-Hbb on mouse chromosome 7. P450-g,h is not linked with P450-b,e and the other markers tested on rat chromosome 1. It appears that close genetic linkage, rather than common functional/regulatory properties, typify members of cytochrome P-450 families/subfamilies.