Neotoma sp.WIKIMEDIA, USGS, KEN COLERats in the Mojave Desert chow down on the toxin-laced leaves of creosote bushes but suffer no ill effects. An analysis of the rodents’ gut microbes now shows that microbial genes help them digest the toxins, according to a study published this week (July 20) in Ecology Letters.
Creosote resin, which coats the surfaces of leaves, is mainly comprised of nordihydroguaiaretic acid, an aromatic compound that can cause liver damage and kidney cysts in lab animals. However, Mojave woodrats consume the resin daily, in amounts that would be lethal to other animals.
The desert rodents only began to consume creosote approximately 17,000 years ago, when climatic changes helped the plant take root in the region. However, creosote did not spread into the adjacent Great Basin desert, where the same species of rats continue to rely on an ancestral diet of juniper. Previous studies found that Mojave rats were able to safely eat approximately 25 percent more creosote than Great Basin rats.
Kevin Kohl of the University of Utah and his colleagues sequenced the ...
