Identification of proteins from the secretory/excretory products (SEPs) of the branchiuran ectoparasite Argulus foliaceus (Linnaeus, 1758) reveals unique secreted proteins amongst haematophagous ecdysozoa

Abstract

Background: It is hypothesised that being a blood-feeding ectoparasite, Argulus foliaceus (Linnaeus, 1758), uses similar mechanisms for digestion and host immune evasion to those used by other haematophagous ecdysozoa, including caligid copepods (e.g. sea louse). We recently described and characterised glands associated with the feeding appendages of A. foliaceus using histological techniques. The work described in the present study is the first undertaken with the objective of identifying and partially characterising the components secreted from these glands using a proteomic approach.Methods: Argulus foliaceus parasites were sampled from the skin of rainbow trout (Oncorhynchus mykiss), from Loch Fad on the Isle of Bute, Scotland, UK. The proteins from A. foliaceus secretory/excretory products (SEPs) were collected from the supernatant of artificial freshwater conditioned with active adult parasites (n = 5-9 per ml; n = 560 total). Proteins within the SEPs were identified and characterised using LC-ESI-MS/MS analysis. Data are available via ProteomeXchange with identifier PXD016226.

Genetic Diversity of Serine Protease Inhibitors in Myxozoan (Cnidaria, Myxozoa) Fish Parasites

“…Intracellular serpins may have various functions, from the inhibition of anti-coagulatory proteases to enhancing lysosome stability [ 19 , 55 ]. Intracellular serpins were detected in the excretory product of blood-feeding parasites such as ticks [ 13 , 14 ], or in the saliva of the fish ectoparasite arthropod, Argulus foliaceus [ 56 ]. These studies concluded that intracellular serpins are supposed to be one of the major components involved in evasion of the host defense mechanisms for successful feeding.…”

Identification of Transcripts Relating to Host-parasite Interactions and Feeding-associated Activities Through De Novo Transcriptome Sequencing of Branchiuran Fish Lice, Argulus Foliaceus (Linnaeus, 1758) and Argulus Coregoni Thorell, 1865

“…Hydrolases have been identi ed from different parasite venoms which are known to include proteases, peptidases and glycosidase enzymes [34,35]. As we have not only identi ed hydrolase transcripts here in Argulus tissues, but also recently in Argulus SEPs through proteomic analysis [11], the presence of hydrolases might re ect their contribution to host-parasite interactions in Argulus species. The identi ed metalloproteases from different arthropods are assumed to be related to different biological processes such as digestion, cuticle degradation and host immune suppression [47].…”

“…As there is no reference genome for Argulus, the transcriptomes of both A. foliaceus and A. coregoni were assembled de novo using Trinity v2.1.1 software. The assembled transcriptomes are important for both genomic and proteomic studies [11], especially in terms of providing the complete ORF information for genes coding for proteins that may play important roles in biological processes and might therefore provide potentially suitable vaccine candidates [12] or targets for anti-parasiticides.…”

“…A general lack of knowledge in this area led von Reumont et al (2014) to call for studies looking into the composition of the expected active secretions originating from branchiuran exocrine glands associated with feeding [10]. Due to limited genomic resources, we recently identi ed only 27 proteins in the secretory / excretory products (SEPs) of Argulus foliaceus [11]. Some of the compounds identi ed have also been described from other host-associated Crustacea, particularly the parasitic copepod Lepeophtheirus salmonis (Krøyer, 1837) [12].…”

“…Although argulids affect aquaculture and sheries globally, causing major economic impacts for freshwater aquacultured sh species worldwide, few studies have examined the mechanisms underlying physiological and behavioural aspects of the parasite [11]. In the UK, Argulus spp.…”