title: Molecular cloning and expression of a Toll receptor in the giant tiger shrimp, Penaeus monodon.
abstract: Invertebrates rely completely for their protection against pathogens on the innate immune system. This non-self-recognition is activated by microbial cell wall components with unique conserved molecular patterns. Pathogen-associated molecular patterns (PAMPs) are recognised by pattern recognition receptors (PRRs). Toll and its mammalian homologs Toll-like receptors are cell-surface receptors acting as PRRs and involved in the signalling pathway implicated in their immune response. Here we describe a novel partial Toll receptor gene cloned from a gill library of the giant tiger shrimp, Penaeus monodon, using primers based on the highly conserved Toll/IL-1R (TIR) domain. The deduced amino acid sequence of the P. monodon Toll (PmToll) shows 59% similarity to a Toll-related protein of Apis mellifera. Analysis of the LRRs of shrimp Toll contained no obvious PAMP-binding insertions. Phylogenetic analysis with the insect Toll family shows clustering with Toll1 and Toll5 gene products, and it is less related to Toll3 and Toll4. Furthermore, RT-qPCR shows that PmToll is constitutively expressed in gut, gill and hepatopancreas. Challenge with white spot syndrome virus (WSSV) shows equal levels of expression in these organs. A role in the defence mechanism is discussed. In conclusion, shrimp possess at least one Toll receptor that might be involved in immune defence.
authors.affiliation: Cell Biology and Immunology Group, Wageningen University, Marijkeweg 40, 6709 PG Wageningen, The Netherlands. joop.arts@wur.nl
authors.forename: Joop A J
authors.initials: JA
authors.lastname: Arts
authors.forename: Ferry H J
authors.initials: FH
authors.lastname: Cornelissen
authors.forename: Tony
authors.initials: T
authors.lastname: Cijsouw
authors.forename: Trudi
authors.initials: T
authors.lastname: Hermsen
authors.forename: Huub F J
authors.initials: HF
authors.lastname: Savelkoul
authors.forename: René J M
authors.initials: RJ
authors.lastname: Stet
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D005786:Gene Expression Regulation; D033561:Penaeidae / Q000235:genetics* / Q000378:metabolism* / Q000821:virology; D010802:Phylogeny; D016415:Sequence Alignment; D051193:Toll-Like Receptors / Q000737:chemistry / Q000235:genetics*; D046848:White spot syndrome virus 1 / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D051193:Toll-Like Receptors