Rapid and pervasive mitochondrial heteroplasmy with recombination in the bed bug, Cimex lectularius

Homoplasmy, the occurrence of a single mitochondrial DNA haplotype within an individual, has been the accepted condition across most organisms in the animal kingdom. In recent years, a number of exceptions to this rule have been reported, largely due to the ease with which single nucleotide polymorphisms can be detected. Evidence of heteroplasmy – two or more mitochondrial variants within a single individual – has now been documented in a number of invertebrates; however when present, heteroplasmy usually occurs at low frequencies both within individuals and within populations. The implications of heteroplasmy may be far reaching, both to the individual in relation to its health and fitness, and when considering the evolutionary dynamics of populations. Here, we present evidence for frequent mtDNA heteroplasmy in U.S. and European populations of the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae). Based upon laboratory crosses of differentially homoplasmic lineages we propose that this heteroplasmy is driven by frequent paternal leakage in concert with rapid and pervasive mtDNA recombination. The ecological and evolutionary significance of mtDNA heteroplasmy will be discussed along with its implications for inferring infestation dynamics in this resurging species.