Lyme Disease in the Ecosystem
Lyme Disease
by the Numbers
Lyme disease is the fastest-growing vector-borne illness in the U.S., with hundreds of thousands affected each year. Despite its scale, reliable testing and effective long-term treatment remain major challenges.
What causes
Lyme disease?
Lyme disease spreads through the bite of ticks, which feed on different hosts at each stage of their life cycle. Immature ticks (larvae and nymphs) typically feed on small animals like white-footed mice, which act as both a food source and a reservoir for the Lyme-causing bacteria. When nymphs bite humans, they can transmit the disease, caused by a bacteria called Borrelia burgdorferi. Adult ticks later feed on larger animals like deer, which help sustain the tick population but do not carry the disease.
By targeting the mice that infect young ticks, we can break the cycle of transmission at its source.
What makes engineering wild mice so hard?
The white-footed mouse (Peromyscus leucopus) is 25 million years removed from the common lab mouse (Mus musculus)
White-footed mice (Peromyscus leucopus) may look like lab mice, but they’re surprisingly distant relatives — separated by over 25 million years of evolution. In fact, they’re more genetically different from lab mice (Mus musculus) than lab mice are from rats. That evolutionary gap means none of the standard lab protocols for gene editing, embryo culture, or breeding applied. Every step — from handling embryos to delivering genes — had to be researched, adapted, and often completely redesigned for this species.
Peromyscus mice are found in nearly every terrestrial habitat across North America, thriving in forests, beaches, grasslands, and deserts. With over 50 recognized species, their remarkable adaptability makes them a powerful model for studying evolution, disease, and environmental resilience.
Their widespread presence also plays a key role in the ecology of tick-borne illnesses, making them especially important for understanding and interrupting disease transmission.
A Widespread Species with Big Impacts
(Top left) The forest-dwelling deer mouse, P. maniculatus nubiterrae (Top right) The beach mouse, P. polionotus phasma (Bottom left) The oldfield mouse, P. polionotus sumneri (Bottom Right) The cotton mouse, P. gossypinus
Benefits of Studying Peromyscus
for Human Health
Peromyscus mice offer a unique window into human biology. Unlike inbred lab strains, they display natural genetic diversity and long lifespans, making them powerful models for studying traits like aging, development, metabolism, and immune function.
A Future Without
Tick-Borne Disease
From Lyme to babesiosis and beyond, ticks transmit a growing number of illnesses across the U.S. Because Peromyscus mice are a key reservoir for several of these pathogens (specifically those that transmit Lyme disease, babesiosis, and anaplasmosis), studying them offers a unique opportunity to stop transmission at its source. By unlocking the biology of these resilient, widespread mice, we’re building a future where tick-borne disease can be prevented—not just treated.
