Characterization of the first non-mammalian T2 cytokine gene cluster: the cluster contains functional single-copy genes for IL-3, IL-4, IL-13 and GM-CSF, a gene for IL-5 which appears to be a pseudogene and a gene encoding another cytokine-like transcript, KK34.

S. Avery, Lisa Rothwell, W. G. J. Degen, Virgil E J C Schijns, J. Young, Pete Kaiser, J. Kaufman

Research output: Contribution to journalArticlepeer-review

Abstract

A genomics approach based on the conservation of synteny was used to develop a bacterial artificial chromosome (BAC) contig across the chicken T2 cytokine gene cluster. Sequencing of representative BACs showed that the chicken genome encodes genes for the homologs of mammalian interleukin-3 (IL-3), IL-4, IL-5, IL- 13, and granulocyte-macrophage colony-stimulating factor (GM-CSF). These sequences represent the first T2 cytokines found outside of mammals, and their location demonstrates that the T2 cluster is ancient (at least 300 million years old). Four of these genes (IL-3, IL-4, IL-13, and GM-CSF) are expressed at the mRNA level and can be expressed as recombinant protein. In contrast to the other four genes, the chicken IL-5 (ChIL-5) gene we sequenced lacks a recognizable promoter and regulatory sequences in the predicted 3'-untranslated region (3'-UTR). Further, there is no evidence for its expression at the mRNA level. We, therefore, hypothesize that it is a pseudogene. Genomic analysis revealed that a recently characterized cytokinelike transcript, KK34, not identified in our initial analysis of the BAC sequence, is also encoded in this cluster. This gene may represent a duplication of an ancestral IL-5 gene and may encode the functional homolog of IL-5 in the chicken.
Original languageEnglish
Pages (from-to)600-610
Number of pages11
JournalJournal of Interferon and Cytokine Research
Volume24
Issue number10
DOIs
Publication statusPublished - 2004

Fingerprint

Dive into the research topics of 'Characterization of the first non-mammalian T2 cytokine gene cluster: the cluster contains functional single-copy genes for IL-3, IL-4, IL-13 and GM-CSF, a gene for IL-5 which appears to be a pseudogene and a gene encoding another cytokine-like transcript, KK34.'. Together they form a unique fingerprint.

Cite this