Sequences at the somatic recombination sites of immunoglobulin light-chain genes

Abstract

The entire nucleotide sequence of a 1.7-kilobase embryonic DNA fragment containing five joining (J) DNA segments for mouse immunoglobulin kappa chain gene has been determined. Each J DNA segment can encode amino acid residues 96--108. Comparison of one of the five J DNA sequences with those of an embryonic variable (V) gene and a complete kappa chain gene permitted localisation of a precise recombination site. The 5'-flanking regions of J DNA segments could form an inverted stem structure with the 3'-non-coding region of embryonic V genes. This hypothetical structure and gel-blotting analysis of total embryo and myeloma DNA suggest that the somatic recombination may be accompanied by excision of an entire DNA segment between a V gene and a J DNA segment. Antibody diversity may in part be generated by modulation of the precise recombination sites.

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

“…It and K4878 and K4872 came from the State Serum Institute, Copenhagen, whereas K19, K20, K23 and K31 came from the Rockefeller University colony. Thus a portion of the data comes from families produced by matings of brother-sister and of other close Results and Discussion Table I presents the findings indicating independent assortment of FR and CDR segments and defining a possible J segment that contains two residues of CDR3 as established earlier in the mouse (19,20,24) and as proposed for the rabbit (31).…”

“…Sakano et al (19), Max et al (20), and Weigert et al (24) have proposed that some diversity in J could have been generated by intracodon recombination when the J nucleotides are joined to the rest of the V region. If one attempts such intracodon recombinations assuming CCC to be preserved at the beginning of the intervening sequence in the rabbit as in the mouse, the prototype set Ile Val would generate Leu or Pro at position 97E, neither of which has been found.…”

“…Rudikoff et al ~ also consider that in the fll ---* 6 galactans, the alternative amino acids at position 96 do not contribute to complementarity. Thus the intracodon recombination proposed (19,20,24) as a mechanism for V-J joining and for reducing the number ofJ minigenes might create sequence diversity without contributing significantly to those complementarity differences which would make for various antibody specificities. 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.…”

“…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. Thus, as defined, theJ segments are clearly minigenes (12,13).…”

Convenient plasmid vectors for construction of chimeric mouse/human antibodies

“…pSV2gpt [17] and pSV2neo [18] were provided by P. Berg (Stanford). Mouse J, gene-containing fragment (JX probe) was isolated from clone Ig146 [19]. Mouse JH probe was isolated from MEP203 [20].…”