The distribution and spread of naturally occurring Medea selfish genetic elements in the United States

摘要

Selfish genetic elements (SGEs) are DNA sequences that are transmitted to viable offspring in greater than Mendelian frequencies. SGEs occur naturally in some populations of red flour beetle ( ) and are expected to increase in frequency within populations and spread among populations. The large‐scale U.S. distributions of (M ) had been mapped based on samples from 1993 to 1995. We sampled beetles in 2011–2014 and show that the distribution of M in the United States is dynamic and has shifted southward. By using a genetic marker of (M ), we found five unique geographic clusters with high and low M frequencies in a pattern not predicted by microsatellite‐based analysis of population structure. Our results indicate the absence of rigid barriers to spread in the United States, so assessment of what factors have limited its current distribution requires further investigation. There is great interest in using synthetic SGEs, including synthetic , to alter or suppress pest populations, but there is concern about unpredicted spread of these SGEs and potential for populations to become resistant to them. The finding of patchy distributions of elements suggests that released synthetic SGEs cannot always be expected to spread uniformly, especially in target species with limited dispersal.