Microsatellite Analysis Comparing the Genetic Variation of Culex tarsalis Populations across Montana

Abstract

West Nile Virus (WNV), first detected in Montana in 2002, is transmitted by the mosquito Culex tarsalis in Montana. The purpose of the WNV project at Carroll College is to produce an infection risk assessment map for the state of Montana, created by determining the factors that affect the prevalence of the virus across the state. The objective of this specific study is to add one layer to the risk assessment map by using microsatellite analysis to compare the variation of genetic structure of differing populations of Cx. tarsalis across Montana. I hypothesized that the genetic differences (as measured by values) between pairs of populations would be lower if the populations are connected by waterways and are near in distance to each other. By inference, populations separated by large distances or by geographic barriers should have higher values. PCR amplification of three microsatellite loci for 12 populations was followed by high-resolution gel electrophoresis using the QIAxcel Advanced System to determine alleles present for each individual. Number of alleles per locus, null allele frequencies, and values were calculated using FreeNA and FSTAT. The number of alleles per locus ranged from 8–12. Null allele frequencies ranged from 0–0.38. values ranged from 0.005–0.39. Presence of null alleles and missing data made analyses difficult. values do not allow for either rejection or support of the hypothesis.