Genomes of trombidid mites reveal novel predicted allergens and laterally-transferred genes associated with secondary metabolism

Dong, Xiaofeng, Chaisiri, Kittipong, Xia, Dong, Armstrong, Stuart D ORCID: 0000-0002-3862-1801, Fang, Yongxiang ORCID: 0000-0002-4514-5292, Donnelly, Martin J, Kadowaki, Tatsuhiko ORCID: 0000-0002-4622-1218, McGarry, John W, Darby, Alistair C ORCID: 0000-0002-3786-6209 and Makepeace, BL ORCID: 0000-0002-6100-6727 (2018) Genomes of trombidid mites reveal novel predicted allergens and laterally-transferred genes associated with secondary metabolism. GigaScience, 7 (12).

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Abstract

Background: Trombidid mites have a unique life cycle in which only the larval stage is ectoparasitic. In the superfamily Trombiculoidea (“chiggers”), the larvae feed preferentially on vertebrates, including humans. Species in the genus Leptotrombidium are vectors of a potentially fatal bacterial infection, scrub typhus, that affects 1 million people annually. Moreover, chiggers can cause pruritic dermatitis (trombiculiasis) in humans and domesticated animals. In the Trombidioidea (velvet mites), the larvae feed on other arthropods and are potential biological control agents for agricultural pests. Here, we present the first trombidid mites genomes, obtained both for a chigger, Leptotrombidium deliense, and for a velvet mite, Dinothrombium tinctorium. Results: Sequencing was performed using Illumina technology. A 180 Mb draft assembly for D. tinctorium was generated from two paired-end and one mate-pair library using a single adult specimen. For L. deliense, a lower-coverage draft assembly (117 Mb) was obtained using pooled, engorged larvae with a single paired-end library. Remarkably, both genomes exhibited evidence of ancient lateral gene transfer from soil-derived bacteria or fungi. The transferred genes confer functions that are rare in animals, including terpene and carotenoid synthesis. Thirty-seven allergenic protein families were predicted in the L. deliense genome, of which nine were unique. Preliminary proteomic analyses identified several of these putative allergens in larvae. Conclusions: Trombidid mite genomes appear to be more dynamic than those of other acariform mites. A priority for future research is to determine the biological function of terpene synthesis in this taxon and its potential for exploitation in disease control.

Item Type:	Article
Uncontrolled Keywords:	chigger, trombiculid, scrub typhus, terpenes, isoprenoids, horizontal transfer, Leptotrombidium, Dinothrombium, Tetranychus, Trombidiformes
Depositing User:	Symplectic Admin
Date Deposited:	20 Nov 2018 11:24
Last Modified:	19 Jan 2023 01:12
DOI:	10.1093/gigascience/giy127
Open Access URL:	https://doi.org/10.1093/gigascience/giy127
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3028947