Identification of Ig sigma and Ig lambda in channel catfish, Ictalurus punctatus, and Ig lambda in Atlantic cod, Gadus morhua
2009 (English)In: Immunogenetics, ISSN 0093-7711, E-ISSN 1432-1211, Vol. 61, no 5, 353-370 p.Article in journal (Refereed) Published
Immunoglobulin light (IGL) chain genes encoding sigma and lambda from channel catfish, Ictalurus punctatus, and lambda from Atlantic cod, Gadus morhua, were identified by mining of expressed sequence tag databases, 5'-RACE and RT-PCR protocols. cDNAs for each of these IGL chains encode typical variable (V), joining (J), and constant (C) regions and Southern blot analyses and genomic sequencing show that genes encoding these isotypes, like other teleost IGL genes, are found in a cluster organization of one or two V gene segments, followed by single J and C gene segments, all in the same transcriptional orientation. However, unlike the teleost kappa genes, genes encoding catfish sigma and lambda are few in number and the two isotypes are each encoded by only two clusters. Similarly, Atlantic cod lambda genes are predicted to be encoded by two or three clusters. As expected, sequence and phylogenetic analyses comparisons demonstrate that catfish V sigma and C sigma genes are most similar to V sigma and C sigma genes of other ectothermic vertebrates. Although catfish and Atlantic cod V lambda genes cluster with other vertebrate V lambda genes, their C lambda sequences cluster in a distinct group separate from other vertebrate IGL C sequences. However, support for classifying these sequences as lambda, is their V and J recombination signal sequence (RSS) organization. The catfish and Atlantic cod genes have typical lambda-like RSS with the V lambda RSS consisting of heptamer-23 bp spacer-nonamer and the J lambda RSS consisting of heptamer-12 bp spacer-nonamer. This is the first report demonstrating the presence of Ig lambda in teleosts.
Place, publisher, year, edition, pages
2009. Vol. 61, no 5, 353-370 p.
Immunoglobulin light chains, Sigma, Lambda, Isotype, Channel catfish, Atlantic cod
IdentifiersURN: urn:nbn:se:uu:diva-129091DOI: 10.1007/s00251-009-0365-zISI: 000265685900003OAI: oai:DiVA.org:uu-129091DiVA: diva2:337565