Host-specifity of monogeneans ectoparasites on fish skin and gills assessed by a metabarcoding approach
Description
Monogeneans are highly diverse fish ectoparasites with a direct life cycle widely distributed and are known to generally display a strict host specificity. However, monogeneans have also been observed to colonize fish species not in their natural host range under experimental conditions. The aim of this study is therefore to investigate how monogenean host-specificity establishes during the infection in nature using a new molecular approach. We developed a specific metabarcoding protocol based on restriction enzymes and specific primers and applied it on the Sparidae-Lamellodiscus host parasite system, to assess parasite diversity on skin and gills of several sparid host species. Here, we provided i) the metadata file, 2) the ASV table with sequences assigned with the SILVA 138 database, 3) the ASV table rarefied, 4) the ASV table rarefied with assignments of all monogenean sequences by BLAST and 5) the final ASV table which summarizes all Lamellodiscus sequences identified in each sample. We identified a high diversity of both expected and unexpected (never observed on this host species) Lamellodiscus species on each host species and on skin and gills. These results suggest that the establishment of the observed host specificity in monogeneans relies on multiple levels of regulation and is more complex than initially described.
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Steps to reproduce
The analysis of the raw sequences was done using the QIIME2 software and the standard pipeline of DADA2. Briefly, raw reads were demultiplexed, quality-checked and trimmed to remove primer regions, paired ends were assembled, chimeric sequences were discarded, and reads were denoised. Sequences were aligned against the SILVA 138 reference database (using qiime feature-classifier classify-sklearn) distributed by the Silva project. Samples 87 to 97 need to be removed, they were sequenced for another sequencing project. In order to achieve a finer taxonomical resolution, especially for monogeneans species, we performed additional BLAST search (95 % minimum similarity). Based on the classification, all unassigned sequences were removed. By analyzing the rarefaction plot, the data were reduced to 2011 sequences. Three samples were discarded (one from skin mucus (B. boops) and two from gill mucus (B. boops and P. acarne) samples). The remaining sequences were used to assess the diversity of monogeneans among fish species and tissues.
Institutions
- Biologie Integrative des Organismes Marins
- Sorbonne Universite
- Observatoire Oceanologique de Banyuls-sur-Mer