A complete immunoglobulin gene is created by somatic recombination

Brack, Christine; Hirama, Minoru; Lenhard-Schuller, Rita; Tonegawa, Susumu

doi:10.1016/0092-8674(78)90078-8

Cited by 500 publications

(272 citation statements)

References 22 publications

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“…Indeed, even if antibody site complementarity were to be generated by position 96 as in McPC603 when an actual J sequence was assembled somatically by joining to the rest of the V region, it would not necessarily follow that the other amino acids if created at position 96 by intracodon recombination would necessarily function as CDR residues in CDR3 although conceivably they might influence other residues in CDR3 conformationally so that they become contacting. Indeed, although the discovery of the J minigene and of somatic assembly at the DNA level between the 12th d of embryonic life and the adult (12,15,17,18,26) is a seminal development in molecular genetics, it has tended to focus attention on position 96 and away from the other CDR residues that are crucial to the generation of antibody diversity, of idiotypic specificity, and of their interrelations.…”

Section: Methodsmentioning

confidence: 99%

“…Because we only assorted FR segments, the findings would be independent of whether one or two residues of a given CDR assorted with any FR segment. Studies by Tonegawa et al with cloned mouse Vx (14,15) and V~ (16) genes and by Seidman et al (17,18) with mouse V, genes showed that in 12-d-old embryo DNA, genes coding for residues 1-95 of the V region were followed by an intervening sequence.…”

mentioning

confidence: 99%

“…Other genes for the mouse h-region coded for residues 96-108, termed the J segment and were followed by an intervening sequence of about 1.2 Kb and then by the Cx coding segment (15). In mouse V, chains (19,20), a clone coding for C, contained five J segments, each separated by an intervening sequence that varied in length from 246 to 310 base pairs and with an intervening sequence of-2.5 Kb between the ol closest to C and the C region.…”

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confidence: 99%

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Evidence indicating independent assortment of framework and complementarity-determining segments of the variable regions of rabbit light chains. Delineation of a possible J minigene.

Kabat¹,

Wu²,

Bilofsky³

1980

The Journal of Experimental Medicine

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The variable (V) 1 regions of immunoglobulin light chains when aligned for maximum homology can be divided into four framework regions (FR) separated by three complementarity-determining (CDR) (hypervariable [1]) regions or segments (2, 3). The latter as predicted (1), together with the corresponding three CDR of the heavy chain (4), form the antibody-combining sites (3-11). Light chains FR1, FR2, FR3, and FR4 comprise residues 1-23, [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][98][99][100][101][102][103][104][105][106][107] CDR2,[50][51][52][53][54][55][56][89][90][91][92][93][94][95][96][97]. If the FR segments were grouped into sets of identical sequence and the members of each set were traced, it was shown (12) that members of a given FRI set could be associated with different FR2, FR3, and FR4 sets. This independent assortment suggested that the FR sets, and by implication the CDR sets, were under different genetic control, and the hypothesis was put forward that the individual FR and CDR sets were controlled by minigenes assembled somatically by recombination at the DNA level (12). A minigene is defined as a segment of DNA coding for a portion of a domain and which shows evidence of segregation as a functional unit independent of the rest of the DNA coding for the V region (13). Because we only assorted FR segments, the findings would be independent of whether one or two residues of a given CDR assorted with any FR segment. Studies by Tonegawa et al. with cloned mouse Vx (14, 15) and V~ (16) genes and by Seidman et al. (17,18) with mouse V, genes showed that in 12-d-old embryo DNA, genes

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Evidence indicating independent assortment of framework and complementarity-determining segments of the variable regions of rabbit light chains. Delineation of a possible J minigene.

Kabat¹,

Wu²,

Bilofsky³

1980

The Journal of Experimental Medicine

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“…Aside from the utility of cDNA's for defining the initiation, coding, and termination sequences of mRNA's, their use as hybridization probes makes it possible to search for, isolate, identify, and characterize the corresponding genes from chromosomal DNA. Indeed, it was comparisons between cloned cDNA's and their genomic counterparts that uncovered the existence of intervening sequences (4,5,9,19,38) and splicing (37) and the occurrence of genomic rearrangements in the formation of functional immunoglobulin genes (3). More recently, the cloning of cDNA copies of RNA virus genomes (e.g., vesicular stomatitis [32], polio [22], and influenza viruses [35]) has opened the way to a more refined understanding of these viruses' structure, replication, and expression, as well as providing a simpler route for the development of antiviral vaccines (17).…”

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confidence: 99%

High-efficiency cloning of full-length cDNA.

Okayama¹,

Berg²

1982

Mol. Cell. Biol.

1,134

498

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A widely recognized difficulty of presently used methods for cDNA cloning is obtaining cDNA segments that contain the entire nucleotide sequence of the corresponding mRNA. The cloning procedure described here mitigates this shortcoming. Of the 105 plasmid-cDNA recombinants obtained per ,ug of rabbit reticulocyte mRNA, about 10%o contained a complete a-or P-globin mRNA sequence, and at least 30 to 50%o, but very likely more, contained the entire globin coding regions. We attribute the high efficiency of cloning full-or nearly fulllength cDNA to (i) the fact that the plasmid DNA vector itself serves as the primer for first-and second-strand cDNA synthesis, (ii) the lack of any nuclease treatment of the products, and (iii) the fact that one of the steps in the procedure results in preferential cloning of recombinants with full-length cDNA's over those with truncated cDNA's.

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“…Studies by Tonegawa and coworkers (11)(12)(13) and by Seidman et al (14,15) have led to the isolation from 12-day mouse embryo of cloned DNA gene segments coding for V, and VA chains from FRI almost to the end of CDR3.…”

mentioning

confidence: 99%

Some sequence similarities among cloned mouse DNA segments that code for lambda and kappa light chains of immunoglobulins.

Kabat²,

Bilofsky³

1979

Proc. Natl. Acad. Sci. U.S.A.

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A comparison between the cloned mouse DNA segments that were found to code for the X and K light chains of immunoglobulins established that there were seven short nucleotide sequences, two of which matched 6 out of 7, two 7 out of 8, two 8 out of 9, and one 9 out of 10 bases; these sequences were located either at homologous amino acid positions or at positions displaced by four amino acids or less. They all occurred in the framework regions (FRs), five next to the complementarity-determining regions (CDRs). Three of these were unique and did not occur elsewhere in the immunoglobulin nucleotides sequenced thus far or in DNAs of phage 4X174, phage G4, or simian virus 40. Five could serve as sites of joining by recombination or insertion of CDR to FR segments, and the invariant tryptophan that is the first residue of the second FR might serve as a sixth. These sites are consistent with the minigene or insertional hypotheses for the generation of antibody diversity but could also serve as points of recognition for a mutator enzyme or could serve to limit somatic mutation to the CDRs.The vast amount of experimental data on amino acid sequences of immunoglobulin variable regions (V regions) (1) has provided a basis for trying to understand antibody diversity. From a statistical analysis of such sequences (2, 3) as they were being accumulated, the three complementarity-determining (hypervariable) regions or segments (CDRs) were recognized in the light (L) and in the heavy (H) chains and predicted to form the walls of the antibody combining site; this has been verified by x-ray crystallography in four different laboratories (refs. 4-7; see ref. 8). As a consequence of this analysis each immunoglobulin chain was divided into four framework regions (FRs) separated by the three CDRs as follows: FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4. It was recognized that a simple mechanism for assembling the chains could be the insertion of nucleotides coding for the CDRs into those coding for the FR segments to assemble a complete V-region gene (2, 3). When the various FR segments for each chain were arranged into sets (9), each set being made up of segments identical in sequence, it was noted that the members of a given FR1 set could be associated with different FR2 sets, FR3 sets, and FR4 sets. This independent assortment of FR sets led to the hypothesis (9) that the V-region gene is assembled from sets of germ line minigenes for the FR segments and inferentially from sets of minigenes for the CDRs. A minigene was defined as a DNA segment coding for a portion of the V region that shows some evidence of segregation as a functional unit independent of the rest of the DNA coding for the V region (10). It was further hypothesized that the minigenes were assembled somatically during differentiation. Because assortment was demonstrated only for FR segments, it would be independent of whether one or two CDR residues assorted with a given FR. The CDRs could not be examined for independent assortment because there were too few tha...

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A complete immunoglobulin gene is created by somatic recombination

Cited by 500 publications

References 22 publications

Evidence indicating independent assortment of framework and complementarity-determining segments of the variable regions of rabbit light chains. Delineation of a possible J minigene.

Evidence indicating independent assortment of framework and complementarity-determining segments of the variable regions of rabbit light chains. Delineation of a possible J minigene.

High-efficiency cloning of full-length cDNA.

Some sequence similarities among cloned mouse DNA segments that code for lambda and kappa light chains of immunoglobulins.

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