Cloning of penaeidin gene promoter in tiger shrimp ( Penaeus monodon)

Penaeidins belong to a family of antimicrobial peptides that are expressed in the hemocytes of penaeid shrimps. Using an extender PCR method and a nested PCR, we cloned two types of genomic fragment flanking the 5′ end of penaeidin gene in tiger shrimp ( Penaeus monodon): Type536 and Type411 sequences. Both fragments contained TATA box, GATA, dorsal and AP-1 motifs and were ligated to an expression vector with a luciferase reporter gene. The constructs were then delivered into Drosophila S2 cell line. The promoter functions of the two fragments were determined using a luciferase expression assay. The study demonstrated that Type411 sequence performed higher transcriptional activity than Type536. Alignment of the upstream sequences of penaeidin genes in P. monodon and Litopenaeus vannamei showed that the promoter regions were obviously more diverse than the 5′UTRs. Phylogenetic analysis indicated the presence of two types of promoters that are not species-specific in the two shrimps.