The dynamic TCR?: TCR? chains in the amphibian Xenopus tropicalis utilize antibody-like V genes.

ABSTRACT: The content and organization of the Xenopus tropicalis TCR?/? locus was determined. This locus is highly conserved among tetrapods, with the genes encoding the TCR? chains embedded with those encoding TCR?. However, the frog TCR?/? is unusual in that it contains V genes that appear indistinguishable from those in the IgH locus (VH). These V genes, termed VH?, make up 70% of the V genes at the TCR? locus and are expressed exclusively in TCR? chains. Finding TCR? chains that use antibody-like V domains in frogs is similar to the situation in shark TCR? variants and TCR? in marsupials. These results suggest that such unconventional TCR may be more widespread across vertebrate lineages than originally thought and raise the possibility of previously unrealized subsets of T cells. We also revealed close linkage of TCR?/?, IgH, and Ig? in Xenopus which, in combination with linkage analyses in other species, is consistent with the previous models for the emergence of these antigen receptor loci.

SUBMITTER: Parra ZE 

PROVIDER: S-EPMC3086071 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature