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ARS Home » Plains Area » Kerrville, Texas » Knipling-Bushland U.S. Livestock Insects Research Laboratory » Livestock Arthropod Pest Research Unit » Research » Publications at this Location » Publication #427625
Research Project: Biology, Management, and Surveillance of Ticks of Veterinary Importance

Location: Livestock Arthropod Pest Research Unit

Title: Contrasting epigenetics of Ixodes scapularis populations

Author
item GUZMAN-VALENCIA, STEPHANIE - University Of Wisconsin
item CASSENS, JACOB - University Of Minnesota
item Saelao, Perot
item LEAL, ABAGAIL - University Of Wisconsin
item LOHSTROH, ELIZABETH - University Of Wisconsin
item HARVEY, CRISTINA - University Of Wisconsin
item LEAL-GALVAN, BRENDA - Texas A&M University
item CHAMBERS, CROSS - Texas A&M University
item WRIGHT, CRYS - Texas A&M University
item Tietjen, Mackenzie
item CHAVEZ, ADELA - University Of Wisconsin

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2026
Publication Date: 5/6/2026
Citation: Guzman-Valencia, S., Cassens, J., Saelao, P., Leal, A., Lohstroh, E., Harvey, C., Leal-Galvan, B., Chambers, C., Wright, C., Tietjen, M., Chavez, A.O. 2026. Contrasting epigenetics of Ixodes scapularis populations. Scientific Reports. https://doi.org/10.1038/s41598-026-51703-8.
DOI: https://doi.org/10.1038/s41598-026-51703-8

Interpretive Summary: Blacklegged ticks, the main vector of Lyme disease in the US, live in both cold northern states and warm southern states. This study explored if epigenetics, specifically DNA methylation which is a process that affects gene activity, helps ticks adapt to these different climates. Researchers compared ticks from Minnesota and Texas and found significant differences in their DNA methylation patterns and related gene activity. Northern ticks showed lower methylation levels, especially in genes tied to metabolism and development. These findings suggest that epigenetic changes may help ticks survive in diverse environments, offering new insight into how they thrive across the country.

Technical Abstract: Hard ticks are a source of public health concern, in part due to their ability to inhabit different environmental regions, which increases human encounters. In the United States (U.S.), blacklegged ticks (Ixodes scapularis Say), the primary vector of Lyme disease, exhibit various phenotypes depending on their geographic region (i.e. northern and southern U.S. ticks). Although genetics may partially explain how blacklegged tick populations acclimate to two contrasting environmental conditions in the U.S., epigenetics may also contribute to their success. Epigenetic mechanisms, such as DNA methylation, might modulate gene expression that allows for rapid adaptation. To gain insight into the potential contribution of DNA methylation an Enzyme-Linked Immunosorbent Assay (ELISA) was utilized to test differences in DNA methylation levels between blacklegged ticks collected from Minnesota (northern region) and Texas (southern region). DNA methylation profiles from both populations were defined using bisulfite and Nanopore sequencing. Our results revealed significant variability in methylation levels between the southern and northern tick populations and a highly variable relative expression of DNA methyltransferases and demethylases. Overall, in the northern region, the ticks exhibited a reduction in DNA methylation with a greater number of hypomethylated sites harbored in genes compared to southern ticks. Basic proline-rich protein, sortilin-related receptor, and peptidase M20 domain-containing protein 2-like are among the genes that exhibit a reduction in DNA methylation. Our findings revealed that blacklegged tick populations possess distinctive DNA methylation profiles, which may contribute to their ability to readily adapt to diverse climatic conditions. Our findings aim to pave the way for future research into the potential molecular mechanisms that allow ticks to successfully acclimatize to their present habitat.