title: Ig light chain variability in DNP(494)-KLH immunised sea bass (Dicentrarchus labrax L.): evidence for intra-molecular induced suppression.
abstract: The coding sequence of the sea bass light chain was obtained by sequential anchored PCR on a head kidney cDNA library of a DNP(494)-KLH immunised sea bass. The cDNA sequence obtained codes for a leader peptide of 21aa and a mature IgL chain of 223aa. Both the amino acid sequence comparisons and neighbour-joining trees showed that the IgL chain of sea bass obtained is of the L1/G type. To study the variability of the light chain, additional PCRs on the cDNA library and cDNA from pooled head kidneys were performed. Multiple alignment of unique sequences (N=17) could be performed without introducing gaps, and showed extremely low variability in CDR1, and no variability in CDR2 or CDR3. A possible explanation for this low variability of the IgL1 chain might be the enhanced expression of monospecific anti-DNP antibodies. The isolation and characterisation of partial genomic and cDNA IgL sequences, which showed normal variability, corroborate this explanation.
authors.affiliation: Institute for Molecular and Cell Biology-University of Porto, Rua do Campo Alegre, 823 4150, Porto, Portugal.
authors.forename: N M
authors.initials: NM
authors.lastname: dos Santos
authors.forename: T
authors.initials: T
authors.lastname: Hermsen
authors.forename: J H
authors.initials: JH
authors.lastname: Rombout
authors.forename: L
authors.initials: L
authors.lastname: Pilström
authors.forename: R J
authors.initials: RJ
authors.lastname: Stet
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000276:immunology*; D001483:Base Sequence; D001492:Bass / Q000235:genetics* / Q000276:immunology; D015139:Blotting, Southern; D018076:DNA, Complementary; D014644:Genetic Variation; D006241:Haptens / Q000276:immunology*; D006433:Hemocyanins / Q000276:immunology*; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000145:classification / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000145:classification / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000145:classification / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: C042158:2,4-dinitrophenyl keyhole limpet hemocyanin; D000941:Antigens; D018076:DNA, Complementary; D006241:Haptens; D007127:Immunoglobulin Constant Regions; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D006433:Hemocyanins