Protist.guru: A Comparative Transcriptomics Database for Protists

[Display omitted] •https://protist.guru/ is an online comparative gene co-expression database for 17 protists.•The database contains tools to compare gene expression profiles, coexpression networks, and find functionally enriched co-expression clusters.•We exemplify https://protist.guru/ by identifying a co-expression cluster involved the biosynthesis of secondary carotenoids in Haematococcus lacustris.•Thus, https://protist.guru/ provides easy to use tools to study gene expression and gene function in protists. During the last few decades, the study of microbial ecology has been enabled by molecular and genomic data. DNA sequencing has revealed the surprising extent of microbial diversity and how microbial processes run global ecosystems. However, significant gaps in our understanding of the microbial world remain, and one example is that microbial eukaryotes, or protists, are still largely neglected. To address this gap, we used gene expression data from 17 protist species to create protist.guru: an online database equipped with tools for identifying co-expressed genes, gene families, and co-expression clusters enriched for specific biological functions. Here, we show how our database can be used to reveal genes involved in essential pathways, such as the synthesis of secondary carotenoids in Haematococcus lacustris. We expect protist.guru to serve as a valuable resource for protistologists, as well as a catalyst for discoveries and new insights into the biological processes of microbial eukaryotes. The database and co-expression networks are freely available from http://protist.guru/. The expression matrices and sample annotations are found in the supplementary data.