02071nas a2200169   4500008004100000245018500041210006900226260001600295300001300311490000700324520142900331100002201760700002701782700002401809700001601833856005201849       2016                        eng d00aThe Mitochondrial Cytochrome Oxidase Subunit I Gene Occurs on a Minichromosome with Extensive Heteroplasmy in Two Species of Chewing Lice, Geomydoecus aurei and Thomomydoecus minor0 aMitochondrial Cytochrome Oxidase Subunit I Gene Occurs on a Mini  cFeb-09-2016  ae01622480 v113 a<p>In animals, mitochondrial DNA (mtDNA) typically occurs as a single circular chromosome with 13 protein-coding genes and 22 tRNA genes. The various species of lice examined previously, however, have shown mitochondrial genome rearrangements with a range</p>
<p>of chromosome sizes and numbers. Our research demonstrates that the mitochondrial genomes of two species of chewing lice found on pocket gophers, Geomydoecus aurei and Thomomydoecus minor, are fragmented with the 1,536 base-pair (bp) cytochrome-oxidase subunit I (cox1) gene occurring as the only protein-coding gene on a 1,916&ndash;1,964 bp mini- circular chromosome in the two species, respectively. The cox1 gene of T. minor begins with an atypical start codon, while that of G. aurei does not. Components of the non-protein coding sequence of G. aurei and T. minor include a tRNA (isoleucine) gene, inverted repeat sequences consistent with origins of replication, and an additional non-coding region that is smaller than the non-coding sequence of other lice with such fragmented mitochondrial genomes. Sequences of cox1 minichromosome clones for each species reveal extensive length and sequence heteroplasmy in both coding and noncoding regions. The highly vari- able non-gene regions of G. aurei and T. minor have little sequence similarity with one another except for a 19-bp region of phylogenetically conserved sequence with unknown function.</p>
1 aPietan, Lucas, L.1 aSpradling, Theresa, A.1 aDemastes, James, W.1 aShao, Renfu  uhttp://dx.plos.org/10.1371/journal.pone.0162248