Discovery of J chain in African lungfish (Protopterus dolloi, Sarcopterygii) using high throughput transcriptome sequencing: implications in mucosal immunity.

ABSTRACT: J chain is a small polypeptide responsible for immunoglobulin (Ig) polymerization and transport of Igs across mucosal surfaces in higher vertebrates. We identified a J chain in dipnoid fish, the African lungfish (Protopterus dolloi) by high throughput sequencing of the transcriptome. P. dolloi J chain is 161 aa long and contains six of the eight Cys residues present in mammalian J chain. Phylogenetic studies place the lungfish J chain closer to tetrapod J chain than to the coelacanth or nurse shark sequences. J chain expression occurs in all P. dolloi immune tissues examined and it increases in the gut and kidney in response to an experimental bacterial infection. Double fluorescent in-situ hybridization shows that 88.5% of IgM⁺ cells in the gut co-express J chain, a significantly higher p

SUBMITTER: Tacchi L 

PROVIDER: S-EPMC3743840 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature