Genome streamlining in a minute herbivore that manipulates its host plant

• Published in: eLife Vol. 9
• Main Authors: Greenhalgh, Robert, Dermauw, Wannes, Glas, Joris J, Rombauts, Stephane, Wybouw, Nicky, Thomas, Jainy, Alba, Juan M, Pritham, Ellen J, Legarrea, Saioa, Feyereisen, René, Van de Peer, Yves, Van Leeuwen, Thomas, Clark, Richard M, Kant, Merijn R
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 23.10.2020; eLife Sciences Publications, Ltd; eLife Sciences Publications Ltd
• Subjects: Acari; Animals; Evolution, Molecular; Evolutionary Biology; Genes; Genetics and Genomics; Genome; genome reduction; Genomes; Genomics; Herbivory; horizontal gene transfer; Host-Pathogen Interactions; Lycopersicon esculentum - parasitology; miniaturization; Mites - genetics; Phylogeny; Plants (Organisms); Potatoes; proboscipedia; Proteins; reverse transcriptase-mediated intron loss; Tomatoes; Transposons; Vegetable industry; proboscipedia; evolutionary biology; genetics; genome reduction; Acari; genomics; miniaturization; reverse transcriptase-mediated intron loss; horizontal gene transfer
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.56689

The tomato russet mite, is among the smallest animals on earth. It is a worldwide pest on tomato and can potently suppress the host's natural resistance. We sequenced its genome, the first of an eriophyoid, and explored whether there are genomic features associated with the mite's minute size and lifestyle. At only 32.5 Mb, the genome is the smallest yet reported for any arthropod and, reminiscent of microbial eukaryotes, exceptionally streamlined. It has few transposable elements, tiny intergenic regions, and is remarkably intron-poor, as more than 80% of coding genes are intronless. Furthermore, in accordance with ecological specialization theory, this defense-suppressing herbivore has extremely reduced environmental response gene families such as those involved in chemoreception and detoxification. Other losses associate with this species' highly derived body plan. Our findings accelerate the understanding of evolutionary forces underpinning metazoan life at the limits of small physical and genome size.