Diet-dependent gene expression highlights the importance of Cytochrome P450 in detoxification of algal secondary metabolites in a marine isopod

Pierre De Wit,Marina Panova,Keith Yamada,Kerstin Johannesson,Carl André

doi:10.1038/s41598-018-34937-z

Pierre De Wit, Marina Panova + Show 3 more

Open Access

https://doi.org/10.1038/s41598-018-34937-z

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Journal: Scientific Reports	Publication Date: Nov 14, 2018
Citations: 8	License type: open-access

Affiliation: University of Gothenburg, University of Turku

Abstract

Isopods of the genus Idotea have an unusual ability to feed on algae containing high amounts of chemical defense molecules, such as species of the genera Fucus and Ulva. In this study, we compared gene expression patterns of Idotea balthica individuals fed with Fucus vesiculosus to individuals fed with Ulva lactuca. We generated the first-ever transcriptome assembly for this species, and found 3,233 differentially expressed genes across feeding regimes. However, only a handful of biological functions were enriched with regard to differentially expressed genes, the most notable being “alkaloid metabolic process”. Within this category, we found eight differentially expressed cytochrome P450 (CYP) unigenes, all of which had a higher expression in the U. lactuca diet treatment. A phylogenetic analysis showed that the differentially expressed CYP genes are closely related to a CYP gene described from the hepatopancreas of the spiny lobster Panulirus argus, and we hypothesize that these transcripts are involved in metabolite detoxification. This is a first step in the understanding of this algae-grazer interaction, and will form a basis for future work to characterize cytochrome P450 functioning in marine crustaceans.

Highlights

Isopod crustaceans of the globally distributed genus Idotea are common in coastal marine areas
If the latter was the case, we predicted a diversity of different Cytochrome P450 forms in the transcriptome sequence of I. balthica, of which many would be differentially expressed in different diet treatments, and that these would be similar in sequence to variants of Cytochrome P450 found in other marine algal grazers
The Cytochrome P450 family 2 is involved in detoxification of xenobiotic compounds by monooxygenation or hydroxylation, thereby inactivating potential bioactive compounds which have been ingested[35]

Summary

Introduction

Isopod crustaceans of the globally distributed genus Idotea are common in coastal marine areas. A highly efficient general detoxification mechanism for toxic compounds can be fine-tuned based on the diet This would allow them to be generalists while still feeding on algal species with high quantities of secondary metabolites such as F. vesiculosus and U. lactuca. While very few comparative studies have been conducted to date on crustacean CYP variants, it has been suggested that generalist algal grazers would benefit from the evolution of a high diversity of CYP genes[27,28], as has been observed in the genome sequence of the purple urchin (Strongylocentrotus purpuratus)[29] Each of these could evolve an ability to metabolize a specific group of compounds, generating a finely-tuned diet-based detoxification machinery. If the latter was the case, we predicted a diversity of different Cytochrome P450 forms in the transcriptome sequence of I. balthica, of which many would be differentially expressed in different diet treatments, and that these would be similar in sequence to variants of Cytochrome P450 found in other marine algal grazers

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