Jay Gogue, Interim President of the NMSU System | New Mexico State University
Jay Gogue, Interim President of the NMSU System | New Mexico State University
Woodrats, a species known for their ability to consume large amounts of the poisonous creosote shrub, have been the subject of a study led by biologists at the University of Utah. This research aims to understand how animals adapt to toxic diets over evolutionary time. The study identifies specific genes and enzymes that allow woodrats to ingest creosote without apparent harm.
Teri Orr, an assistant professor at New Mexico State University (NMSU), contributed as a co-author to this research. The findings suggest that natural selection has led to an increase in detoxification genes among woodrat populations exposed to creosote. These duplicated genes enable the production of more detoxifying enzymes rather than creating specialized ones.
Dylan Klure, a postdoctoral researcher at the University of Utah and lead author of the study, commented on this rapid adaptation: “These woodrats have only been exposed to creosote bush for about 15,000 years—in an evolutionary timescale, that’s very little time.” He added that gene duplication is what allows these animals to become toxin-resistant quickly.
Published in Science on January 10 under the title "Parallel gene expansions drive rapid dietary adaptation in herbivorous woodrats," this study contrasts two primary hypotheses regarding animal evolution toward toxin tolerance. One hypothesis suggests modification of existing enzymes; another proposes increased enzyme production through gene duplication—a theory supported by this research.
Denise Dearing from the University of Utah explained: “We discovered that creosote-feeding woodrats don’t have specialized enzymes...just more—many more.”
This investigation into detox DNA involved examining two species, N. lepida and N. bryanti. Michael Shapiro from the University of Utah noted significant genomic changes between tolerant and sensitive woodrats after feeding them low doses of creosote toxins.
The study also highlights potential implications for human biology due to similarities in detoxification pathways between humans and rodents. Teri Orr plans further exploration into diet-related reproduction challenges faced by female woodrats consuming toxic plants while lactating.
Funding was provided by several organizations including the National Science Foundation and National Institutes of Health.
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