Comparison of Host Selection and Gene Expression of Adult Lepeophtheirus Salmonis and Salmo Salar During a Cohabitation of Initially Infected and Uninfected Fish
Date
2014-04
Authors
Wotton, Heather J.
Purcell, Sara L.
Covello, Jennifer M.
Koop, Ben F.
Fast, Mark D.
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Aquaculture Research & Development
Abstract
Lepeophtheirus salmonis is a common parasite of salmonid fish and has a significant economic impact on Atlantic salmon (Salmo salar) fish farms. Over time L. salmonis has developed resistance to a number of chemotherapeutants, making the discovery of new treatments important to maintain a profitable farming industry. Determining processes in both L. salmonis and Atlantic salmon important to host selection and colonization may provide new targets for treatment development. During a two week cohabitation of L. salmonis infected and uninfected Atlantic salmon, we were able to collect information on the ability of L. salmonis to switch hosts, and preference for infected or uninfected fish. Whole L. salmonis and Atlantic salmon tissues were collected at 2 and 14 days post cohabitation to determine if differential gene expression was occurring during this process. At 2 days post cohabitation there was no significant difference in the number of male lice on the initially infected and uninfected fish. Eight L. salmonis genes putatively associated with various facets of lice survival (CYP18 A1-like, cytochrome p450 Isoform 1-like protein, glycene receptor α-2-like, leukocyte receptor cluster member 9-like, nicotinic acetylcholine receptor subunit-like, tissue plasminogen activator precursor-like, peroxinectin-like, and Trypsin-1) were analysed in both adult male and female lice, as well as five genes indicating immune status in Atlantic salmon. Comparisons were made to look for differential gene regulation as well as correlation between expression of L. salmonis genes and Atlantic salmon genes. Only MMP9 expression in salmon spleen was differentially regulated during the study period, however, correlations between the expression of several louse and salmon genes were found. Notably, the expression of a peroxinectin-like gene in male and female L. salmonis was correlated with the expression of IL-1, IL-12, IgT and matrix metalloproteinase 9 intermittently in salmon. This paper provides new insight into the interactions between L. salmonis and S. salar during infection.
Description
The authors would like to thank Dr. Shona Whyte for her review of an earlier version of the manuscript and the Aquatics Facilities and Staff at the Atlantic Veterinary College for their role in maintaining the Atlantic salmon. Furthermore, the authors would like to thank funding agencies, Innovation PEI, EWOS Innovation and Novartis Animal Health for their financial support for this work.
Keywords
Atlantic salmon, Lepeophtheirus salmonis, Host-parasite interactions, Peroxinectin
Citation
Wotton, H.J., Purcell, S.L., Covello, J.M., Koop, B.F., & Fast, M.D. (2014). Comparison of host selection and gene expression of adult Lepeophtheirus salmonis and Salmo salar during a cohabitation of initially infected and uninfected fish. Journal of Aquaculture Research & Development, 5(3), 1-8.