Immunoglobulin heavy chain gene organization in mice: analysis of a myeloma genomic clone containing variable and alpha constant regions.

Abstract

(V and C) and the a heavy chain has four (V, CHi, CH2, and CH3) (2). The variable and constant regions of light chains are encoded by three distinct gene segments, V (approximately residues 1-99), J or joining (approximately residues 100-112), and C (approximately residues 113-219) (3, 4). The V and J segments encode the classical V region. Each of these DNA segments is separated by intervening nucleotide sequences in embryo or undifferentiated DNA (4). Studies of myeloma DNA suggest that these gene segments are rearranged during the differentiation of antibody-producing cells. However, in myeloma DNA, intervening sequences still separate the V and C segments (4). These intervening sequences must be removed from nuclear RNA transcripts of light chain genes by RNA splicing (5). Thus, DNA rearrangements and RNA splicing appear to be important events in the differentiation of antibody-producing cells (6).We are interested in analyzing the genes coding for heavy chains in embryo and myeloma DNA to determine whether sequence rearrangements occur during differentiation that are comparable to those seen for light chain gene segments (4). Our initial approach has been to isolate genomic clones from a library of recombinant Charon 4A bacteriophage containing long fragments of M603 myeloma DNA. In this paper we report the characterization of one clone containing both VH and Ca regions. DP50SupF (19,21). Duplicate nitrocellulose filters from each plate were prehybridized in 1 M NaCl/0.045 M trisodium citrate/0.2% bovine serum albumin/0.2% Ficoll/0.2% polyvinylpyrrolidone/0.1% sodium Abbreviations: V, variable; C, constant; NaDodSO4, sodium dodecyl sulfate; kb, kilobase(s); IVS, intervening sequence(s). f To whom reprint requests should be addressed. 857The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

Genetic engineering in the Precambrian: structure of the chicken triosephosphate isomerase gene.

“…Gilbert (24,25) proposed that exons are the descendants of ancient genes encoding small polypeptides with simple functions that were duplicated and reassorted to create genes for more complex proteins. This hypothesis was supported by the fact that the exons of the immunoglobulin genes corresponded to the functional and structural domains of antibody proteins (10,20,42,49). The correlation is also apparent for collagen (50, 52), ovomucoid (46), a-fetoprotein (21), and -y-crystallin (37), which are divided in a way that reflects the repeating nature of the proteins that they encode.…”

Restricted reassociation of heavy and light chains from hapten-specific monoclonal antibodies.

“…One approach has involved amino acid sequence analyses of myeloma proteins (1,2) and, more recently, hybridoma proteins (3). Another approach has been the cloning (4) and hybridization (5) of DNAs coding for these complex group ofproteins. Both approaches have contributed to current views of antibody diversity and genetics.…”

Comparison of mouse immunoglobulin gamma 2a and gamma 2b chain genes suggests that exons can be exchanged between genes in a multigenic family.

“…The nucleotide sequence shows that, as in the case of all heavy chain genes so far studied (11)(12)(13)(14) The sequences of the 'y2a and y2b chain genes have been aligned to maximize the homology. As previously shown, the DNA sequences corresponding to the CHi, CH2, and CH3 domains and the 3' untranslated region can be aligned without introducing deletions or insertions, although two deletions must be introduced in the hinge region.…”

“…Immunoglobulin heavy chain genes are interrupted by introns located at homologous positions (11)(12)(13)(14). It is likely that all of the CH genes are derived from a common ancestor having a similar structural organization consisting of exonic segments alternating with introns with the last exonic segment linked to the 3' untranslated region.…”