Characterization of immunoglobulin light chain isotypes in the common carp

Abstract

Two or three isotypes of immunoglobulin (Ig) light (L) chain have been demonstrated in several teleost species thus far. A reverse transcription-polymerase chain reaction (RT-PCR) strategy was used with the aim of isolating cDNA clones encoding IgL chain from the common carp ( Cyprinus carpio. L.) different from the previously isolated isotype, designated L1A. cDNA clones representing two novel isotypes, designated L1B and L3, were obtained in this study. For CL segments, L1B sequences were similar to type L1/G in various teleost species, as well as L1A, while L3 sequences were closely related with type L3/F in catfish and zebrafish. For VL segments, however, L1A sequences demonstrated higher similarity to L3 rather than L1B. These results were also supported by the phylogenetic study. The similarity found between L1A and L3 VL sequences was based on the very high degree of nucleotide identity in FR1, and/or FR2 to FR3, strongly suggesting the involvement of interlocus recombination between them. Southern blot analyses suggested that the locus of L1B has a cluster-like organization, but that those of L3 and L1A are currently unknown due to cross-hybridization between those VL probes. Northern blot analyses showed that CL mRNA of each isotype was expressed in lymphoid tissues examined, particularly strongly in pronephros, and was predominantly composed of approximately 1-kb and 0.6-kb transcripts, possibly corresponding to fully spliced (LVJC) and truncated (JC/J-C) forms, respectively.

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.…”

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

“…The four IgL isotypes were expressed abundantly in the lymphoid tissues of trout, which was similar with that obtained from carp L1a and L1b (Tomana et al, 2002), salmon L1, L2 and L3 (Solem and Jorgensen, 2002), catfish IgLl and IgLs (Edholm et al, 2009), orange-spotted grouper CL-I to CL-IV (Wu et al, 2013), large yellow croaker (Pseudosciaena crocea) IgL1 to IgL3 (Tian et al, 2011). Besides, the transcripts of trout IgLs were also detected in the non-lymphoid tissues, such as heart and liver, which might be due to the remain of peripheral blood lymphocytes in these tissues.…”

“…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.…”

“…Based on this nomenclature, the originally reported teleost IgL1 and IgL3 can be classified into IgLkG and IgLkF, respectively, and IgL2 into IgLs. All of these three IgL isotypes have been identified in rainbow trout (Oncorhynchus mykiss) (Daggfeldt et al, 1993;Partula et al, 1996;Timmusk et al, 2000), zebrafish (Danio rario) (Haire et al, 2000;Zimmerman et al, 2008), common carp (Cyprinus carpio L.) (Ishikawa et al, 2004;Tomana et al, 1999Tomana et al, , 2002, and channel catfish (Ictalurus punctatus) Lobb, 1993, 1997). Recently, another IgL isotype, phylogenetically homologous to mammalian l, was found in channel catfish and Atlantic cod (Gadus morhua) (Edholm et al, 2009).…”

Marine Organism Cell Biology and Regulatory Sequence Discoveryin Comparative Functional Genomics

“…Large-scale genetic screens produced more than 500 zebrafish mutants, many with phenotypes similar to human disorders (Dooley and Zon 2000). Immunogenetic studies in carp, salmonids and other species are contributing to the growing database of marine vertebrate genomics Fujiki et al 2001Fujiki et al , 2003Tomana et al 2002;Ishikawa et al 2004).…”