Intervening sequences divide the gene for the constant region of mouse immunoglobulin μ chains into segments, each encoding a domain

Abstract

To elucidate the structure of the gene for the constant region of immunuglobulin μ chains, we have cloned a 9.9-kilobase-pair fragment of mouse DNA bearing a gene for the constant region of the μ chain (Cμ gene) from an IgM-secreting mouse plasmacytoma. The sequence around this gene has apparently undergone somatic rearrangement; the gene occurs in an EcoRI restriction endonuclease fragment of a different size from that in embryo or liver DNA and no Cμ-bearing fragment of embryo size remains in the plasmacytoma. The cloned sequence lacks a variable region gene; hence, if this Cμ gene is active, its position within the clone indicates that the gene for the variable region of a heavy chain (V(..