01760nas a2200157   4500008004100000245013800041210006900179260000900248300001400257490000700271520122100278100001601499700002301515700002401538856004001562       2009                        eng d00aThe single mitochondrial chromosome typical of animals has evolved into 18 minichromosomes in the human body louse, Pediculus humanus0 asingle mitochondrial chromosome typical of animals has evolved i  c2009  a904 - 9120 v193 aThe mitochondrial (mt) genomes of animals typically consist of a single circular chromosome that is ∼16-kb long and has 37 genes. Our analyses of the sequence reads from the Human Body Louse Genome Project and the patterns of gel electrophoresis and Southern hybridization revealed a novel type of mt genome in the sucking louse, Pediculus humanus. Instead of having all mt genes on a single chromosome, the 37 mt genes of this louse are on 18 minicircular chromosomes. Each minicircular chromosome is 3–4 kb long and has one to three genes. Minicircular mt chromosomes are also present in the four other species of sucking lice that we investigated, but not in chewing lice nor in the Psocoptera, to which sucking lice are most closely related. We also report unequivocal evidence for recombination between minicircular mt chromosomes in P. humanus and for sequence variation in mt genes generated by recombination. The advantages of a fragmented mt genome, if any, are currently unknown. Fragmentation of mt genome, however, has coevolved with blood feeding in the sucking lice. It will be of interest to explore whether or not life history features are associated with the evolution of fragmented chromosomes.1 aShao, Renfu1 aKirkness, Ewen, F.1 aBarker, Stephen, C.  uhttps://cats.myspecies.info/node/17