The Lower Peninsula of Michigan is inhabited by the white-footed deer mouse Peromyscus leucopus, which has been identified as the reservoir host for the Lyme disease-causing bacterium, Borrelia burgdorferi, due to its ability to maintain the bacterial infection for long periods of time. The vector for B. burgdorferi transmission between hosts is the deer tick, Ixodes scapularis. Young ticks become infected by feeding on infected small vertebrate hosts, primarily P. leucopus, and older nymphs and adults can then pass along the infection when they feed on large mammals, including humans. The Lower Peninsula is not yet completely colonized by B. burgdorferi; currently, Manistee and Benzie Counties are at the northern limit of its spread from a hotspot in Wisconsin, with mouse and tick populations that include both infected and uninfected individuals. We are analyzing genetic and demographic data from mice in these counties to investigate whether the different rates of B. burgdorferi infection we’ve observed could be related to certain mice being genetically more susceptible to the bacteria. Our genetic analysis incorporates fluorescent microsatellite marking and Genemapper fragment analysis, while our demographic assessment encompasses variables such as sex, age, weight, ear size, and B. burgdorferi infection rates. We hypothesize that individual mice that are infected with B. burgdorferi are more closely related to each other than to uninfected mice.
Author(s): Noelle Wittwer, Adam Livingston, Allie Mangan, Ibrahim Barakat
Advisor(s): Susan Hoffman, Biology