Effects of chitin synthesis inhibitor treatment on Lepeophtheirus salmonis (Copepoda, Caligidae) larvae

Overview
TitleEffects of chitin synthesis inhibitor treatment on Lepeophtheirus salmonis (Copepoda, Caligidae) larvae
AuthorsHarðardóttir HM, Male R, Nilsen F, Dalvin S
TypeJournal Article
Journal NamePloS one
Volume14
Issue9
Year2019
Page(s)e0222520
CitationHarðardóttir HM, Male R, Nilsen F, Dalvin S. Effects of chitin synthesis inhibitor treatment on Lepeophtheirus salmonis (Copepoda, Caligidae) larvae. PloS one. 2019; 14(9):e0222520.

Abstract

The salmon louse (Lepeophtheirus salmonis) is an ectoparasite infecting Atlantic salmon (Salmo salar), which causes substantial problems to the salmon aquaculture and threatens wild salmon. Chitin synthesis inhibitors (CSIs) are used to control L. salmonis in aquaculture. CSIs act by interfering with chitin formation and molting. In the present study, we investigated the action of four CSIs: diflubenzuron (DFB), hexaflumuron (HX), lufenuron (LF), and teflubenzuron (TFB) on larval molt. As the mode of action of CSIs remains unknown, we selected key enzymes in chitin metabolism and investigated if CSI treatment influenced the transcriptional level of these genes. All four CSIs interfered with the nauplius II molt to copepodids in a dose-dependent manner. The EC50 values were 93.2 nM for diflubenzuron, 1.2 nM for hexaflumuron, 22.4 nM for lufenuron, and 11.7 nM for teflubenzuron. Of the investigated genes, only the transcriptional level of L. salmonis chitin synthase 1 decreased significantly in hexaflumuron and diflubenzuron-treated larvae. All the tested CSIs affected the molt of nauplius II L. salmonis larvae but at different concentrations. The larvae were most sensitive to hexaflumuron and less sensitive to diflubenzuron. None of the CSIs applied had a strong impact on the transcriptional level of chitin synthesis or chitinases genes in L. salmonis. Further research is necessary to get more knowledge of the nature of the inhibition of CSI and may require methods such as studies of protein structure and enzymological studies.

Author Details
Additional information about authors:
Details
1Hulda María Harðardóttir
2Rune Male
3Frank Nilsen
4Sussie Dalvin
Properties
Additional details for this publication include:
Property NameValue
Journal CountryUnited States
Publication TypeJournal Article
Language Abbreng
LanguageEnglish
Elocation10.1371/journal.pone.0222520
DOI10.1371/journal.pone.0222520
Journal AbbreviationPLoS ONE
Publication Date2019
eISSN1932-6203
ISSN1932-6203
Publication ModelElectronic-eCollection
Cross References
This publication is also available in the following databases:
DatabaseAccession
PMID: PMID:31545833