Ordering of mouse immunoglobulin heavy chain genes by molecular cloning

Abstract

We have determined the order of the mouse immunoglobulin γ1 γ2b, γ2a and ɛ genes by molecular cloning of overlapping chromosomal segments. The results clearly demonstrate that the order is 5′–γ1–(21 kilobases)–γ2b–(15 kilobases)–γ2a–(15 kilobases)–ɛ–3′. There seem to be no J regions at the 5′ side of each constant region gene so far obtained except for the μ gene and these constant region genes seem to have repetitive sequences characteristic of switch (S) regions at their 5′ side.