Identificação de genes relacionados ao sistema imune do camarão marinho Litopenaeus vannamei

Abstract

Viruses are among the most harmful pathogens found in aquaculture and are the most numerous and diverse of the pathogenic agents described to crustaceans. The knowledge about genes associated to immunity viral response, as well as the relationships between pathogen and host still very incomplete. Moreover, shrimp cell lines are not available, thus limiting primary systems of cellular culture to assist searches in genomic expression. The Expressed Sequence Tags (ESTs) analyses have become a common tool used to identify genes involved in some specific biological functions, particularly in organisms in which genomic data are not available. The Laboratory of Applied Genetics (LAGA) of the Universidade Federal Rural de Pernambuco (UFRPE) is one of the members of the Shrimp EST Genome Project (ShEST), assisting on sequencing and search for genes related to shrimp immune response against the viral infections. Libraries of different tissues (muscle, hepatopancreas, ocular peduncle)and different larval stages of Litopenaeus vannamei were sequenced using BigDye Terminator Sequencing Kit (Applied Biosystems) or ET-Dye Terminator (Amersham/GE Healthcare) and M13 universal primer (5'-TGTAAAACGACGGCCAGT-3'). The sequences were analyzed in automated sequencers MegaBace1000 (Amersham/GE Healthcare) and Applied Biosystems 377 (ABI377). These sequences were analyzed using the Basic Local Alignment Search Tool (BLAST). The results presented homology with interferon system proteins, like 2’,5’-Oligoadenylate binding protein, Toll like receptors, JAK/STAT and Interferon like protein. The 2’,5’-Oligoadenylate binding protein would be the first protein related to interferon system described in shrimps. A lot of sequences are still need to be investigated to complete the whole genome of Litopenaeus vannamei, nevertheless there are indications that this animal has a complex antiviral defense system, similar to interferon.