Standard Restriction Fragment Length Analysis of the Mitochondrial Genome Is Not Sensitive Enough for Phylogenetic Analysis or Identification of 17-Year Periodical Cicada Broods (Hemiptera: Cicadidae): the Potential for a New Technique

Abstract

Restriction fragment length polymorphisms (RFLP) in mitochondrial DNA (mtDNA) were examined using 12 different restriction enzymes for three populations (average 12 individuals per population) of brood IV of Magicicada septendecim (L.), one of three 17-year periodical cicada species. The goal of this research was to determine whether mtDNA variation among broods (year classes) exists and is phylogenetically useful. Brood IV was chosen for investigation because allozyme analysis of geographic variation within and among 10 periodical cicada year classes identified western 17-year broods III and IV as divergent from all the eastern 17-year broods. RFLP patterns scored for western brood IV were compared with those previously surveyed for eastern brood X populations. Our data showed brood IV restriction fragments to be identical in all three populations and identical to those of brood X with the exception of one (polymorphic) site which was present in most members of brood IV and had not been detected in brood X. Current research explores the potential for a new technique—restriction enzyme digests of a small section of the mitochondrial molecule amplified via the polymerase chain reaction (PCR—RFLP). Preliminary data reinforce earlier findings that 17-year cicada mitochondrial genomes are remarkably homogeneous.