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Since the larval and adult antibody responses are distinct and restricted in the clawed toad Xenopus, it offers a near ideal model for studying the ontogeny of antibody repertoires and the mechanisms involved. Immunoglobulin heavy chain (IgH) cDNA clones and B cell IgH DNA clones from various larval and adult libraries have been analysed in isogenic Xenopus. Some features are similar in adults and tadpoles, while others differ and explain the particularities observed previously at the protein level. Among the similarities we found are: (i) the mode of rearrangements (there are approximately 50% abortive events in B cells from both stages), (ii) VH family usage (10 of 11 known VH families are expressed proportionally to the number of VH elements per family), and (iii) JH usage (of the eight to nine Xenopus JH elements, two are used in approximately 70% of the VH regions in both stages of development). We found that there is relatively higher membrane exon expression in tadpoles compared with adults; and that most of the differences come from the diversification of CDR3 through DH usage and N diversification. Unlike in mammals, Xenopus DH elements are used with a remarkable flexibility with inversion, fusions and usage in different reading frames, but tadpoles show a strong bias for the usage of only a few DH elements and of a preferred reading frame. There is N diversification, which further increases CDR3 heterogeneity, in adult Xenopus but virtually none in tadpoles. These observations can account for the fact that larval antibody responses are less heterogeneous than those of adults.
Akira,
Two pairs of recombination signals are sufficient to cause immunoglobulin V-(D)-J joining.
1987, Pubmed
Akira,
Two pairs of recombination signals are sufficient to cause immunoglobulin V-(D)-J joining.
1987,
Pubmed Bleicher,
Monoclonal anti-IgM can separate T cell from B cell proliferative responses in the frog, Xenopus laevis.
1981,
Pubmed
,
Xenbase Brandt,
Antibody diversity in amphibians: evidence for the inheritance of idiotypic specificities in isogenic Xenopus.
1980,
Pubmed
,
Xenbase Carlsson,
Genetic basis of the neonatal antibody repertoire: germline V-gene expression and limited N-region diversity.
1990,
Pubmed Chirgwin,
Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease.
1979,
Pubmed Du Pasquier,
Immunoglobulin expression in diploid and polyploid interspecies hybrid of Xenopus: evidence for allelic exclusion.
1983,
Pubmed
,
Xenbase Du Pasquier,
Ontogeny of immunity in amphibians: changes in antibody repertoires and appearance of adult major histocompatibility antigens in Xenopus.
1979,
Pubmed
,
Xenbase Du Pasquier,
Antibody diversity in amphibians: inheritance of isoelectric focusing antibody patterns in isogenic frogs.
1978,
Pubmed
,
Xenbase Feeney,
Lack of N regions in fetal and neonatal mouse immunoglobulin V-D-J junctional sequences.
1990,
Pubmed Gregoire,
Ontogeny of terminal deoxynucleotidyl transferase-positive cells in lymphohemopoietic tissues of rat and mouse.
1979,
Pubmed Gu,
Sequence homologies, N sequence insertion and JH gene utilization in VHDJH joining: implications for the joining mechanism and the ontogenetic timing of Ly1 B cell and B-CLL progenitor generation.
1990,
Pubmed Haire,
Eleven distinct VH gene families and additional patterns of sequence variation suggest a high degree of immunoglobulin gene complexity in a lower vertebrate, Xenopus laevis.
1990,
Pubmed
,
Xenbase Hsu,
Evolution of immunoglobulin genes: VH families in the amphibian Xenopus.
1989,
Pubmed
,
Xenbase Kokubu,
Diverse organization of immunoglobulin VH gene loci in a primitive vertebrate.
1988,
Pubmed Lafaille,
Junctional sequences of T cell receptor gamma delta genes: implications for gamma delta T cell lineages and for a novel intermediate of V-(D)-J joining.
1989,
Pubmed Meek,
Analysis of junctional diversity during B lymphocyte development.
1990,
Pubmed Schwager,
Evolution of immunoglobulin light chain genes: analysis of Xenopus IgL isotypes and their contribution to antibody diversity.
1991,
Pubmed
,
Xenbase Schwager,
Anti-immunoglobulin M induces both B-lymphocyte proliferation and differentiation in Xenopus laevis.
1985,
Pubmed
,
Xenbase Schwager,
Genetic basis of the antibody repertoire in Xenopus: analysis of the Vh diversity.
1989,
Pubmed
,
Xenbase Schwager,
Organization and rearrangement of immunoglobulin M genes in the amphibian Xenopus.
1988,
Pubmed
,
Xenbase Schwager,
Amino acid sequence of heavy chain from Xenopus laevis IgM deduced from cDNA sequence: implications for evolution of immunoglobulin domains.
1988,
Pubmed
,
Xenbase Steinmetz,
A rearranged DNA sequence possibly related to the translocation of immunoglobulin gene segments.
1980,
Pubmed Tonegawa,
Somatic generation of antibody diversity.
1983,
Pubmed Yancopoulos,
Preferential utilization of the most JH-proximal VH gene segments in pre-B-cell lines.
,
Pubmed
