Identification and Molecular Characterization of Two Acetylcholinesterases from the Salmon Louse, Lepeophtheirus salmonis.
Acetylcholinesterase (AChE) is an important enzyme in cholinergic synapses. Most arthropods have two genes (ace1 and ace2), but only one encodes the predominant synaptic AChE, the main target for organophosphates. Resistance towards organophosphates is widespread in the marine arthropod Lepeophtheirus salmonis. To understand this trait, it is essential to characterize the gene(s) coding for AChE(s). The full length cDNA sequences encoding two AChEs in L. salmonis were molecularly characterized in this study. The two ace genes were highly similar (83.5% similarity at protein level). Alignment to the L. salmonis genome revealed that both genes were located close to each other (separated by just 26.4 kbp on the L. salmonis genome), resulting from a recent gene duplication. Both proteins had all the typical features of functional AChE and clustered together with AChE-type 1 proteins in other species, an observation that has not been described in other arthropods. We therefore concluded the presence of two versions of ace1 gene in L. salmonis, named ace1a and ace1b. Ace1a was predominantly expressed in different developmental stages compared to ace1b and was possibly active in the cephalothorax, indicating that ace1a is more likely to play the major role in cholinergic synaptic transmission. The study is essential to understand the role of AChEs in resistance against organophosphates in L. salmonis.
NMBU School of Veterinary Science, Sea Lice Research Centre, PO Box 8146 Dep., NO-0033 Oslo, Norway.
Kiranpreet
K
Kaur
NMBU School of Veterinary Science, Sea Lice Research Centre, PO Box 8146 Dep., NO-0033 Oslo, Norway.
Marit Jørgensen
MJ
Bakke
University of Bergen, Department of Biology, Sea Lice Research Centre, NO-5020 Bergen, Norway.
Frank
F
Nilsen
NMBU School of Veterinary Science, Sea Lice Research Centre, PO Box 8146 Dep., NO-0033 Oslo, Norway.
Tor Einar
TE
Horsberg
D000110:Acetylcholinesterase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D033342:Copepoda / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D018076:DNA, Complementary; D005260:Female; D023061:Gene Order; D016678:Genome; D007527:Isoenzymes; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D014158:Transcription, Genetic
D018076:DNA, Complementary; D007527:Isoenzymes; D000110:Acetylcholinesterase