Immunoglobulin light chain isotypes in the teleost Trematomus bernacchii

Molecular characterization and expression analysis of four isotypes of immunoglobulin light chain genes in orange-spotted grouper, Epinephelus coioides

“…All four C L isotypes could be detected in multiple organs, but expression was most abundant in the lymphoid tissues, head-kidney and spleen. Similar results were previously obtained using Northern blotting or quantitative PCR for rainbow trout L1 and L2, common carp L1A, L1B and L3, Atlantic salmon IgL types 1 to 3, fugu IgL, emerald rockcod L1A, L1B, L2 and L3, channel catfish Igr and Igk, and large yellow croaker L1, L2 and L3 (Coscia et al, 2008;Edholm et al, 2009;Saha et al, 2004;Solem and Jørgensen, 2002;Tian et al, 2011;Timmusk et al, 2000;Tomana et al, 2002). Our analyses also indicated that OsgIgL is expressed in the gill, an important mucosal organ which contains a variety of leukocytes and produces secretory Igs (Salinas Fig.…”

“…The conserved characteristic FR4 (J L ) motif FGXGT exists in all V L types of OsgIgL in one of two forms, FGGGT (V L -I, II, III and IV) or FGQGT (V L -V); in OsgIgH, however, the consensus sequence is WGKGT. Moreover, the FR4 sequence Phe-Gly-Gln-Gly-Thr-LysLeu-Ile-Val (FGQGTKLIV) was observed in the V L -V type OsgIgL, and other r type IgLs in rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio), emerald rockcod (Trematomus bernacchii) and large yellow croaker (Pseudosciaena crocea) (Coscia et al, 2008;Ishikawa et al, 2004;Tian et al, 2011;Timmusk et al, 2000). The two V regions from IgH and IgL compose the antigen binding site surface of Ig molecules, to which three CDR loops from each V domain contribute.…”

“…A tandem Ser-repeat exists within the C L -I and C L -II types of OsgIgL, a feature that is also present in the emerald rockcod L1A and L1B, spotted wolffish L1 and L2, and mandarin fish (Siniperca chuatsi) IgL (Coscia et al, 2008;Espelid and Nygaard Grøntvedt, 2003;Zhang et al, 2003). In addition, the microsatellite sequences (AGC) 6-8 encoding the poly-Ser stretch are present in the IgL of spotted wolffish and mandarin fish, and the L1A of emerald rockcod.…”

Preferential combination between the light and heavy chain isotypes of fish immunoglobulins

“…In the current study, 8 IgL subisotypes were identified and verified in rainbow trout, 3 (including L1) were homologous with IgLkG, 2 (including L3) were related to IgLkF, 2 (including L2) were belonging to IgLs, and the rest one was a member of IgLl. This phenomenon of IgL subisotypes was also found in other teleost, such as IgL1a and IgL1b in carp (Ishikawa et al, 2004;Tomana et al, 1999Tomana et al, , 2002), L1A and L1B in rockcod (Coscia et al, 2008), L1A and L1B in stickleback (Bao et al, 2010), which might be generated due to the teleost-specific and the salmonid-specific whole genome duplication (Berthelot et al, 2014;Hoegg et al, 2004). From the alignment of trout IgLs, the first 4 cysteine residues involving intrachain disulfide bonds were found conserved within the VL and CL domains of all subisotypes, except IgLkG3, which lacks cysteine in its VL region.…”

Antarctic teleost immunoglobulins: More extreme, more interesting

“…Our data provide clear evidence for the presence of three distinct isotypes in T. bernacchii: TrbeL1, TrbeL2, and TrbeL3 were identified by immunoscreening a cDNA expression library, and using RT-PCR, and 5 0 RACE [45]. The constant domains shared high amino acid identity (91.7e95.2%) within the same isotype, but quite low identity between different isotypes (33.4e37.2%).…”