Generating first-ever transgenic ticks to fight Lyme disease.

Close up of a deer tick

Ticks are blood sucking parasites that live on the outside of animals and humans and are distributed worldwide from the Arctic to tropical regions. Ticks are second to mosquitoes as vectors of human diseases globally and are the most important vectors in the United States. The deer tick (Ixodes scapularis) is a vector of the bacteria Borrelia burgdorferi the causative agent of Lyme disease. Over 300,000 Lyme disease cases were reported in the US in 2013.

In addition, deer ticks also carry the infectious agents of human babesiosis, human granulocytic anaplasmosis, tick-borne relapsing fever, ehrlichiosis, and Powassan encephalitis. The increased incidence and distribution of Lyme disease and other tick-borne diseases necessitates new approaches for vector control.

Recent advances in genetic transformation techniques such as clustered, regularly interspaced, short, palindromic repeats (CRISPR/Cas9), have for the first time allowed the relationships between specific genes and their function to be elucidated in other arthropods such as mosquitoes. However, these techniques have not been applied to study tick molecular biology and tick-pathogen interactions.

To date, no transgenic technology exists for any tick species. The Gulia-Nuss team will provide new tools to determine the genetic basis of many tick phenotypes in order to develop novel approaches for tick control and for understanding tick-pathogen interactions that contribute to disease transmission. This work will impact the tick research community by facilitating genetic transformations that are required to overcome a current barrier in the field.

To meet this challenge, the lab of Gulia-Nuss is developing tools to genetically manipulate ticks by the CRISPR/Cas9 gene editing system and/or conventional transgenic approaches.