The immunoglobulin heavy-chain locus in zebrafish: identification and expression of a previously unknown isotype, immunoglobulin Z

摘要: The only immunoglobulin heavy-chain classes known so far in teleosts have been mu and delta. We identify here a previously unknown class, zeta, expressed zebrafish other teleosts. In the locus, variable (V) gene segments lie upstream of two tandem diversity, joining constant (DJC) clusters, resembling mouse T cell receptor alpha (Tcra) delta (Tcrd) locus. V genes rearrange to (DJC)(zeta) or (DJC)(mu) without evidence switch rearrangement. zeta (ighz) Tcrd, which are proximal array, earlier development. adults, ighz was kidney thymus, primary lymphoid organs This additional class adds complexity repertoire raises questions concerning evolution immunoglobulins regulation differential expression ighm.