title: Molecular characterisation and functional analysis of LsChi2, a chitinase found in the salmon louse (Lepeophtheirus salmonis salmonis, Krøyer 1838).
abstract: The salmon louse (Lepeophtheirus salmonis spp.) is an economically important parasite on Atlantic salmon reared in aquaculture globally. Production and degradation of chitin, a major component of the exoskeleton, is the target of some pesticides (Di/Teflubenzuron) used in management of lice on farmed fish. These chemicals inhibit molting of the salmon louse leading to the death of the parasite. We found three chitinases (LsChi1, LsChi2 and LsChi4) in the salmon louse genome. Sequence analysis and phylogeny showed that they belong to the GH18 type of chitinase group and show high sequence similarity to chitinases found in other crustaceans and in insects. Expression patterns were different for all three chitinases suggesting different functions during louse development. Furthermore, the function of LsChi2 was further explored through the use of RNA interference and infection trials. Copepodids with knock down of LsChi2 transcripts were deformed and showed a highly reduced infection success.
authors: SLCR-Sea Lice Research Center, Department of Biology, University of Bergen, Thormøhlensgt. 55, Bergen 5008, Norway.
authors: Christiane
authors: C
authors: Eichner
authors: SLCR-Sea Lice Research Center, Institute of Marine Research, Bergen 5817, Norway.
authors: Ewa
authors: E
authors: Harasimczuk
authors: SLCR-Sea Lice Research Center, Department of Biology, University of Bergen, Thormøhlensgt. 55, Bergen 5008, Norway.
authors: Frank
authors: F
authors: Nilsen
authors: SLCR-Sea Lice Research Center, Department of Biology, University of Bergen, Thormøhlensgt. 55, Bergen 5008, Norway.
authors: Sindre
authors: S
authors: Grotmol
authors: SLCR-Sea Lice Research Center, Institute of Marine Research, Bergen 5817, Norway. Electronic address: sussie.dalvin@imr.no.
authors: Sussie
authors: S
authors: Dalvin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002688:Chitinases / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D033342:Copepoda / Q000033:anatomy & histology / Q000201:enzymology* / Q000235:genetics; D018076:DNA, Complementary / Q000096:biosynthesis; D004478:Ectoparasitic Infestations / Q000469:parasitology / Q000662:veterinary*; D005260:Female; D005393:Fish Diseases / Q000469:parasitology*; D008297:Male; D010802:Phylogeny; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020317:Salmo salar / Q000469:parasitology*; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D012330:RNA, Double-Stranded; D012313:RNA; D002688:Chitinases
keywords: Chitin; Copepod; Ecdysis; Molting; Nauplia; RNA interference