The immunoglobulin gene loci in the teleost Gasterosteus aculeatus

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.…”

“…Furthermore, the gene copy numbers were various among different IgL isotypes, among which IgLk occupied the overwhelming majority. For example, 50 IgLkF and 15 IgLkG clusters as well as 2 IgLs and 2 IgLl clusters were identified in catfish (Edholm et al, 2009;Lobb, 1993, 1997), 29 IgLk and 8 IgLs clusters occurred in stickleback (Bao et al, 2010). In the current study, we also found 21 IgLkG, 4 IgLkF, 2 IgLs and 1 IgLl clusters in trout genome database.…”

Three isotypes of immunoglobulin light chains in large yellow croaker, Pseudosciaena crocea: Molecular cloning, characterization, and expression analysis

“…All together, of the 21 LycIgL genes obtained, 13 were attributed to LycIgL1, 7 to LycIgL2, and only 1 to LycIgL3. In some teleost species, IgL1 could be divided into IgL1A and IgL1B [20,32]. We found that all 13 of the LycIgL1 sequences belonged to LycIgL1A and did not find any LycIgL1B.…”

Discovery and Characterization of Secretory IgD in Rainbow Trout: Secretory IgD Is Produced through a Novel Splicing Mechanism

“…The structure of the d-chain isotypes demonstrates considerable diversity in size, with as few as two constant domains observed in mice and as many as 16 constant domains in zebrafish (Danio rerio) (2). Teleosts demonstrate remarkable plasticity in their d genomic arrangement, with many species possessing repeated blocks of exons encoding Cd2-4 (up to four repeats have been described) as well as duplicated d loci (3)(4)(5). In Atlantic salmon (Salmo salar), a salmon-specific genome duplication event (IGH-A and IGH-B) resulted in parallel d loci that have diverged from each other, resulting in an additional d2-4 repeat in the IGH-B locus (6).…”