Immunoglobulin heavy chain exclusion in the shark.

ABSTRACT: The adaptive immune system depends on specific antigen receptors, immunoglobulins (Ig) in B lymphocytes and T cell receptors (TCR) in T lymphocytes. Adaptive responses to immune challenge are based on the expression of a single species of antigen receptor per cell; and in B cells, this is mediated in part by allelic exclusion at the Ig heavy (H) chain locus. How allelic exclusion is regulated is unclear; we considered that sharks, the oldest vertebrates possessing the Ig/TCR-based immune system, would yield insights not previously approachable and reveal the primordial basis of the regulation of allelic exclusion. Sharks have an IgH locus organization consisting of 15-200 independently rearranging miniloci (VH-D1-D2-JH-Cmu), a gene organization that is considered ancestral to the tetrapod

SUBMITTER: Malecek K 

PROVIDER: S-EPMC2435157 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature