Localization and transcription patterns of LsVasa, a molecular marker of germ cells in Lepeophtheirus salmonis (Krøyer)

Abstract

Lepeophtheirus salmonis (salmon louse) is an ectoparasitic copepod. The salmon louse is an economically important pathogen in aquaculture and poses a serious threat to wild populations of salmonids. Whereas the ecology and biology of the salmon louse has been described to some extent, information on the molecular level is limited. A key step in the struggle to limit the number of salmon lice in farmed fish includes methods to limit reproduction in adult female lice. Here we describe a salmon louse homologue of the germ cell marker Vasa named Lepeophtheirus salmonis Vasa (LsVasa). Vasa, an RNA helicase, is a highly conserved gene found in germ cells in many organisms. The structure and sequence of LsVasa is described and localization and quantification of LsVasa transcripts is presented.

Keywords:

• crustacean
• parasite
• development
• sea lice

Acknowledgements

We are indebted to Heidi Kongshaug, Caterina Sunde, Eva Lina Ljungfeldt and Ingrid Fiksdal for technical assistance in the laboratory and to Sindre Grotmol for revising the manuscript. We would also like to thank the anonymous reviewers. The work has been supported by the FUGE programme in the Norwegian Research Council.