Meeting the challenge of tick-borne disease control:

Abstract

At the ‘One Health’ 9th Tick and Tick-borne Pathogen Conference and 1st Asia Pacific Rickettsia Conference (TTP9-APRC1; http://www. ttp9-aprc1.com), 27 August–1 September 2017 in Cairns, Australia, members of the tick and tick-borne disease (TBD) research communities assembled to discuss a high priority research agenda. Diseases transmitted by hard ticks (subphylum Chelicerata; subclass Acari; family Ixodidae) have substantial impacts on public health and are on the rise globally due to human population growth and change in geographic ranges of tick vectors (de la Fuente et al., 2016). The genus Ixodes is a global menace. Members of the genus impact human and animal health directly via host parasitism, and indirectly via transmission of multiple viral, bacterial and protozoan diseases. The first tick genome assembly was completed in 2016 for Ixodes scapularis (blacklegged tick), the North American vector of Lyme disease (LD), human babesiosis, human anaplasmosis and Powassan virus (Gulia-Nuss et al., 2016). The assembly provided insight into the genome biology of hard (ixodid) ticks and supported molecular studies for many species of Acari (ticks and mites). Draft genome assemblies are available for Ixodes ricinus (castor bean tick; Cramaro et al., 2015; 2017) and Rhipicephalus (Boophilus) microplus (southern cattle tick; Barrero et al., 2017). However, high quality reference assemblies to rival those produced for the mosquito vectors Anopheles gambiae (Neafsey et al., 2015) and Aedes aegypti (Matthews et al., 2017), have not been produced for a tick vector. Conference attendees identified the need to expand genomic resources for tick research, beginning with the genus Ixodes – one of the most important phyletic groups affecting human and animal health worldwide. Inspired by the Anopheles gambiae 1000 genomes effort (Malaria Genomic Epidemiology Network, Ag1000G), an ambitious goal to sequence and assemble the genomes of 1000 Ixodes ticks was proposed. The Ixodes 1000 genomes project (Ix1000G) outlines a “hub and spoke” model to sequence both laboratory reference strains and natural populations of Ixodes. The project is aligned with other ambitious genome initiatives such as the i5K effort that proposes to sequence 5000 arthropod species (Evans et al., 2013) and the Earth BioGenomes project, a moonshot to sequence and catalogue all of Earth’s biodiversity (Lewin et al., 2018). The Ixodes 1000 Genomes Consortium (IGC) represents an international scientific collaboration formed to launch and guide the initiative. This Letter to the Editor defines the strategic vision of the Ix1000G and serves as a call to the broader scientific community for engagement.