Fragmented mitochondrial genomes in two suborders of parasitic lice of eutherian mammals (Anoplura and Rhynchophthirina, Insecta)

Abstract

Parasitic lice (order Phthiraptera) infest birds and mammals. The typical animal mitochondrial (mt) genome organization, which consists of a single chromosome with 37 genes, was found in chewing lice in the suborders Amblycera and Ischnocera. The sucking lice (suborder Anoplura) known, however, have fragmented mt genomes with 9–20 minichromosomes. We sequenced the mt genome of the elephant louse, Haematomyzus elephantis – the first species of chewing lice investigated from the suborder Rhynchophthirina. We identified 33 mt genes in the elephant louse, which were on 10 minichromosomes. Each minichromosome is 3.5–4.2 kb in size and has 2–6 genes. Phylogenetic analyses of mt genome sequences confirm that the elephant louse is more closely related to sucking lice than to the chewing lice in the Amblycera and Ischnocera. Our results indicate that mt genome fragmentation is shared by the suborders Anoplura and Rhynchophthirina. Nine of the 10 mt minichromosomes of the elephant louse differ from those of the sucking lice (Anoplura) known in gene content and gene arrangement, indicating that distinct mt karyotypes have evolved in Anoplura and Rhynchophthirina since they diverged ~92 million years ago.

The complete mitochondrial genomes of two vent squat lobsters, Munidopsis lauensis and M. verrilli: Novel gene arrangements and phylogenetic implications

“…The metazoan mitochondrial genome (mitogenome) is typically a circular double strand DNA molecule, encoding 13 protein‐coding (PCG) genes (seven subunits of the NADH dehydrogenase complex, the cytochrome b subunit of the cytochrome bc1 complex, three subunits of the cytochrome c oxidase, and two subunits of ATP synthase), 22 transfer RNAs (tRNA) genes, two ribosomal RNAs (rRNA, rrnS , and rrnL ) genes, and a control region (CR) including sites for the initiation of transcription and replication (Boore, ). Owing to its small genome size, higher evolutionary rates, limited recombination, and maternal inheritance, (Gissi, Iannelli, & Pesole, ; Simon, Buckley, Frati, Stewart, & Beckenbach, ), mitogenome has been widely used in species identification (Fu, Han, & Xiao, ; Kanmiya et al, ), molecular evolution (Cameron, ; Shao et al, ; Shao, Zhu, Barker, & Herd, ), phylogenetic relationship (Cameron, ; Cameron, Yoshizawa, Mizukoshi, Whiting, & Johnson, ; Chen, Wei, Shao, Dou, & Wang, ; Chen, Wei, Shao, Shi, et al, ), and population genetic (Wei et al, ; Zhang et al, ) studies. Although the gene content is relatively conservative, their rearrangements have been frequently reported, particularly in invertebrates at many taxonomic levels (Cameron, Johnson, & Whiting, ; Hassanin, Léger, & Deutsch, ).…”

Mitochondrial genomes ofColumbicolafeather lice are highly fragmented, indicating repeated evolution of minicircle-type genomes in parasitic lice

“…Highly fragmented mitochondrial genomes in lice were first identified in human lice (Pediculus humanus) (Shao et al 2009), and minicircle-type mitochondrial genomes have since been confirmed in several other genera of sucking lice (Anoplura; Jiang et al 2013, Dong et al 2014a,b, Herd et al 2015, Shao et al 2017, elephant and warthog lice (Rhyncophthirina; Shao et al 2015), and chewing lice in the family Trichodectidae (Cameron et al 2011, Song et al 2019). Phylogenetic analyses have indicated that these three lineages of mammalian lice form a monophyletic group, which suggests highly fragmented mitochondrial genomes evolved once in the common ancestor of this group, as suggested by Song et al (2019).…”

The mitochondrial genome of Globodera ellingtonae is composed of two circles with segregated gene content and differential copy numbers

“…The most highly studied group of organisms with multipartite circles are the mammalian blood-sucking lice in the suborder Anoplura, which have from nine to 20 circles of relatively similar sizes ranging from ~2 to 5 kb [14–18]. Recently, a similar multipartite arrangement was found in the closely related chewing lice suborder Rhynchophthirina [9]. The first metazoan circular multipartite genome to be reported was in a potato cyst nematode (PCN), Globodera pallida , which was shown to have at least six mtDNA circles ranging in size from ~6 to 9 kb [19].…”