Rooting Out Genetic Structure of Invasive Wild Pigs in Texas

Abstract

Invasive wild pigs (Sus scrofa), also called feral swine or wild hogs, are recognized as among the most destructive invasive species in the world. Throughout the United States, invasive wild pigs have expanded rapidly over the past 40 years with populations now established in 38 states. Of the estimated 6.9 million wild pigs distributed throughout the United States, Texas supports approximately 40% of the population and similarly bears disproportionate ecological and economic costs. Genetic analyses are an effective tool for understanding invasion pathways and tracking dispersal of invasive species such as wild pigs and have been used recently in California and Florida, USA, which have similarly long-established populations and high densities of wild pigs. Our goals were to use molecular approaches to elucidate invasion and migration processes shaping wild pig populations throughout Texas, compare our results with patterns of genetic structure observed in California and Florida, and provide insights for effective management of this invasive species. We used a high-density single nucleotide polymorphism (SNP) array to evaluate population genetic structure. Genetic clusters of wild pigs throughout Texas demonstrate 2 distinct patterns: weakly resolved, spatially dispersed clusters and well-resolved, spatially localized clusters. The disparity in patterns of genetic structure suggests disparate processes are differentially shaping wild pig populations in various localities throughout the state. Our results differed from the patterns of genetic structure observed in California and Florida, which were characterized by localized genetic clusters. These differences suggest distinct biological and perhaps anthropogenic processes are shaping genetic structure in Texas. Further, these disparities demonstrate the need for location-specific management strategies for controlling wild pig populations and mitigating associated ecological and economic costs.

From chip to SNP: Rapid development and evaluation of a targeted capture genotyping-by-sequencing approach to support research and management of a plaguing rodent

“…However, such methods may often involve complex laboratory protocols, are constrained to sequencing markers that occur near restriction sites, and can suffer from lack of consistency between samples and studies due to variation in sample DNA degradation, sequencing batch artefacts, and null alleles due to polymorphisms at cut sites [ 11 , 12 ], thereby reducing the final number of useable markers in the final dataset. Still another option is commercial array-based genotyping platforms, which offer rapid and highly robust genotyping at 10,000s to 100,000s of SNPs with minimal lab preparation, and which has seen some recent applications in invasive wildlife research contexts [ 13 ]. However, due to the high costs of development, these arrays are typically restricted to laboratory model organisms or domesticated species, or closely related taxa [ 14 ].…”