Conservation Genetics and Epigenetics of Pronghorn, Antilocapra americana

Abstract

Genetic analyses of increasing power are now regularly incorporated into wildlife management assessments of threatened and endangered species. Genetic data provide valuable information regarding taxonomy, kinship, and population size and structure. Recently transformed by the advent of powerful technologies that expand our view from single genes to the entire genome, the field of conservation may be on the verge of another revolution with the emergence of epigenetics as a promising means of surveying environmental response in natural populations. In this dissertation, I present my doctoral research upon population genetics and epigenetics of pronghorn (Antilocapra americana). Considerable effort has been undertaken to conserve pronghorn, particularly in the periphery of its range in the southwestern United States and northwestern Mexico. Translocation is regularly used to supplement and re-establish populations of the wide-ranging A. a. americana subspecies while captive breeding has been established for two endangered pronghorn subspecies, A. a. sonoriensis found in Arizona and Sonora, Mexico and A. a. peninsularis of the Baja Peninsula. The primary goal of my doctoral work was to provide pronghorn managers with current estimates of genetic diversity, relatedness, and structure within and between pronghorn subspecies in the desert southwest. My work shows that conservation measures for A. a. sonoriensis have successfully maintained genetic diversity within this endangered subspecies. My estimates of population structure within A. a. americana in northern Arizona reveal the influence of translocation and habitat fragmentation and demonstrate the successful reestablishment of gene flow following the removal of highway fences. With the purpose of guiding future release of captive pronghorn, I explored the subspecies status of pronghorn extirpated from a portion of their range in southern California and northern Baja California. My analyses of museum specimens indicate that the historical range of A. a. peninsularis may have extended as far north as the international border while specimens collected just north of the border share more genetic identity with A. a. sonoriensis. To follow my interests in epigenetics, I also conducted the first ever conservation epigenetics study with Arizona pronghorn. I found that pronghorn are more epigenetically than genetically diverse and this is an indicator that further epigenetic study will reveal the signature of response to environmental factors, as it has with other species demonstrating this pattern.