Heteroplasmic mitochondrial genome deletions. (A) Amplicons resulting from conventional PCRs with primers flanking the deletion area (primer positions shown in Figure 1) are shown for a subset of isolates analyzed (genomic DNAs were from bulk nematode extracts). Large bands represent intact mitochondrial genomes that contain the ψND5-2 element; small bands represent deletion-bearing genomes. Samples from the two Kenya clade isolates yielded only a single band of intermediate size due to the absence of ψND5-2 in their mitochondrial genomes. -C indicates the negative control (no genomic DNA) and M indicates the molecular marker (1 kb + DNA ladder from Invitrogen). (B) Estimated ND5 deletion frequencies (y axis) from 22 global superclade C. briggsae natural isolates based on qPCR data. TR indicates tropical-clade isolates and TE indicates temperate-clade isolates. Values shown in bar graph are means from four individual nematodes assayed per genotype – error bars show S. E. M.
Howe and Denver BMC Evolutionary Biology 2008 8:62 doi:10.1186/1471-2148-8-62