Microsatellite Analysis of Gene Flow between Culex tarsalis Populations Connected by Irrigation in Yellowstone County, Montana

Abstract

The purpose of this study was to determine whether population connectivity by irrigation enhances gene flow between Culex tarsalis populations in the state of Montana. Four populations of Cx. tarsalis were collected along the Yellowstone and Bighorn rivers and allele frequencies obtained from PCR amplification of four microsatellite loci, visualized using the QIAxcel Advanced System, were used to assess the genetic structure of the populations. Results of the four loci indicate lower pairwise FST values between only two of three populations connected through waterway, which suggests a disparity in the data. If the genetic similarity between these populations reflects rates of gene flow, these results suggest that higher degrees of gene flow may not be due to irrigation but rather to connectivity by any waterway. Further analysis of additional polymorphic microsatellite loci needs to be performed to determine if a higher degree of gene flow does indeed occur between populations connected by irrigation.