Genomic insights into the Lyme disease vector

Professor David Sattelle of the Division of Medicine at University College London, former member of The Laboratory for Molecular Signalling in The Zoology Department, was part of the international consortium of researchers, who sequenced and analysed the genome of the Lyme disease vector, the tick Ixodes scapularis.

Lyme disease is the most prominent vector–borne disease in Europe and the USA and is on the increase. I. scapularis also vectors human granulocytic anaplasmosis, babeosis and other diseases. Indeed, ticks transmit more diseases to humans and animals than any other arthropod, with important implications worldwide for human health and agriculture. The paper published in Nature Communications (2016) 7:10507, describes the assembly, annotation and analysis of the 2.1 Giga base-pair I. scapularis genome, one of the largest arthropod genomes sequenced to date and is the first for a tick and non-insect arthropod vector. Of particular interest are expansions in gene families associated with tick-host interactions. Insights have been gained into parasitic processes unique to ticks, including ‘questing’ (searching for host), prolonged feeding, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification and prolonged off–host survival.

David’s laboratory have begun to de-orphanise a family of tick cys-loop ligand-gated ion channels. These receptors mediate the fast actions of neurotransmitters such as acetylcholine, GABA and L-glutamate. Receptors of this class are known targets for chemicals used to control other arthropod pests such as insects and mites. Exploring these particular targets offers the prospect of finding new, safer acaricides with good host-tolerance and benefits for animal health and agricultural productivity. The genome has provided access to all members of an important family of candidate acaricide targets and will also expedite a wealth of new studies on the biology of ticks, important arthropod vectors of human and animal diseases.