Researchers at Baylor College of Medicine, in collaboration with Texas A&M AgriLife Research and the U.S. Department of Agriculture Agricultural Research Service, have successfully assembled the first genome for a soft tick species known as Ornithodoros turicata. This work, published in G3: Genes | Genomes | Genetics, is significant because these ticks are vectors for human relapsing fever and could potentially spread African swine fever virus.
The ticks inhabit regions from Florida to Mexico and live in animal burrows and other secluded areas. They can survive more than five years without feeding and can pass pathogens to their offspring, making them crucial disease vectors.
Dr. Job Lopez from Baylor highlighted that "the genome opens up a whole new avenue of research to study the tick, the life cycle, its biology and tick-pathogen interactions." The team began their research using a colony of ticks from Travis County, Texas. Dr. Pete Teel from Texas A&M noted that this colony has been instrumental in many studies over three decades.
Soft ticks differ significantly from hard ticks, particularly regarding gender determination during development stages. One project goal is identifying the chromosome responsible for sex determination.
Lopez emphasized that generating a high-quality genome was critical: "Our goal was to generate a high-quality, chromosome-level genome instead of a highly fragmented genome that is challenging to work with."
The completed genome will help researchers explore chromosomes related to specific biological functions and develop tools for pest control. Teel mentioned that this achievement is vital for population genetics studies across vast geographical ranges.
The emergence of African swine fever in domestic swine populations underscores the importance of understanding these ticks as vectors. Lopez pointed out that "Texas has all the puzzle pieces for the emergence of a natural cycle for the African swine fever virus."
The research aims to understand genetic diversity and adaptation while examining reproductive cycles and pathogen transmission mechanisms in these ticks.
This study involved contributions from several scientists including Mackenzie Tietjen, Amanda R. Stahlke, David Luecke, Perot Saelao, Sheina B. Sim, Scott M. Geib, Brian E. Scheffler, Anna K. Childers, and Alexander R. Kneubehl.
Funding was provided by USDA-ARS through projects such as SCINet and Ag100Pest Initiative.
