Population Genetic Study of the Chewing Louse Geomydoecus ewingi
Abstract
Geomydoecus ewingi is a relatively well-known chewing louse that parasitizes
the pocket gopher Geomys breviceps in the rodent family Geomyidae. Pocket gophers
have been documented to exhibit long-term associations with their parasites, specifically
lice. The flightless and obligate nature of the lice coupled with few opportunities to
colonize new hosts has helped to make them model organisms for cospeciation studies.
A main objective of my research was to determine the microevolutionary processes
driving macroevolutionary patterns, such as cospeciation, in gopher-louse assemblages.
Through the use microsatellite data, a series of population genetic analyses were
conducted on lice parasitizing G. breviceps to better understand the population structure
of lice among host individuals and across localities. With no previous microsatellite data
available, I report 17 novel microsatellite loci in the parasitic chewing louse G. ewingi.
Population genetic analyses infer significant structure among infrapopulations and
potential inbreeding occurring within and among infrapopulations, possibly contributing
to heterozygote deficiency and deviations from Hardy-Weinberg equilibrium. The
microsatellite markers characterized in this study will be useful in future studies
exploring the population dynamics in host-parasite systems, potentially yielding a better
understanding of the processes underlying symbiotic associations.
Citation
Nessner, Caitlin Elizabeth (2014). Population Genetic Study of the Chewing Louse Geomydoecus ewingi. Master's thesis, Texas A & M University. Available electronically from https : / /hdl .handle .net /1969 .1 /152670.