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

Shao R, Barker SC, Li H, Song S, Poudel S, Su Y - Sci Rep (2015)

Bottom Line: 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.Each minichromosome is 3.5-4.2 kb in size and has 2-6 genes.Our results indicate that mt genome fragmentation is shared by the suborders Anoplura and Rhynchophthirina.

View Article: PubMed Central - PubMed

Affiliation: GeneCology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4556, Australia.

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.

No MeSH data available.


Related in: MedlinePlus

Independent evolution of the two mitochondrial (mt) tRNA genes for leucine in mammals (A) and insects (B), and a mixture of both independent and concerted evolution of these two genes in parasitic lice (C).Trees were constructed using neighbor-joining method with MEGA 5.2.2 (Tamura et al. 2011). Bootstrap support values (%) are indicated on branches. All of the mammals and insects in (A) and (B) and the fly and the screamer louse in (C) have the typical, single-chromosome mt genomes of bilateral animals. The elephant louse and the sucking lice (Anoplura) in (C) have fragmented mt genomes with multiple minichromosomes. The human head louse, Pe. h. capitis, was not included in (C) because it has identical sequences with the human body louse, Pe. h. humanus, for trnL1 and trnL2 genes.
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f4: Independent evolution of the two mitochondrial (mt) tRNA genes for leucine in mammals (A) and insects (B), and a mixture of both independent and concerted evolution of these two genes in parasitic lice (C).Trees were constructed using neighbor-joining method with MEGA 5.2.2 (Tamura et al. 2011). Bootstrap support values (%) are indicated on branches. All of the mammals and insects in (A) and (B) and the fly and the screamer louse in (C) have the typical, single-chromosome mt genomes of bilateral animals. The elephant louse and the sucking lice (Anoplura) in (C) have fragmented mt genomes with multiple minichromosomes. The human head louse, Pe. h. capitis, was not included in (C) because it has identical sequences with the human body louse, Pe. h. humanus, for trnL1 and trnL2 genes.

Mentions: We used distance-based neighbor-joining (NJ) method to analyze the sequences of trnL1(tag) and trnL2(taa) genes. The NJ tree showed that these two genes evolved independently in a wide range of species of mammals and insects that have the typical single-chromosome mt genome organization. As would be expected for any pair of homologous genes, trnL1(tag) of a given species was more closely related to trnL1(tag) of other species than it is to trnL2(taa) of its own, and vice versa (Fig. 4A,B; Alignment S3 and S4). In the elephant lice and the sucking lice that have fragmented mt genomes, however, both independent evolution and concerted evolution were observed between the two tRNA genes for leucine (Fig. 4C; Alignment S5). In the two species of pig lice, Haematopinus suis and Haematopinus apri, both trnL genes evolved independently: trnL1(tag) genes of the two species are most closely related to each other whereas trnL2(tag) genes of the two species are most closely related. In the elephant louse, the human lice and the rat louse, Po. spinulosa, however, the two trnL genes evolved in concert: trnL1(tag) of each species is more closely related to trnL2(taa) of the same species than to trnL1(tag) of other species, and vice versa.


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

Shao R, Barker SC, Li H, Song S, Poudel S, Su Y - Sci Rep (2015)

Independent evolution of the two mitochondrial (mt) tRNA genes for leucine in mammals (A) and insects (B), and a mixture of both independent and concerted evolution of these two genes in parasitic lice (C).Trees were constructed using neighbor-joining method with MEGA 5.2.2 (Tamura et al. 2011). Bootstrap support values (%) are indicated on branches. All of the mammals and insects in (A) and (B) and the fly and the screamer louse in (C) have the typical, single-chromosome mt genomes of bilateral animals. The elephant louse and the sucking lice (Anoplura) in (C) have fragmented mt genomes with multiple minichromosomes. The human head louse, Pe. h. capitis, was not included in (C) because it has identical sequences with the human body louse, Pe. h. humanus, for trnL1 and trnL2 genes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663631&req=5

f4: Independent evolution of the two mitochondrial (mt) tRNA genes for leucine in mammals (A) and insects (B), and a mixture of both independent and concerted evolution of these two genes in parasitic lice (C).Trees were constructed using neighbor-joining method with MEGA 5.2.2 (Tamura et al. 2011). Bootstrap support values (%) are indicated on branches. All of the mammals and insects in (A) and (B) and the fly and the screamer louse in (C) have the typical, single-chromosome mt genomes of bilateral animals. The elephant louse and the sucking lice (Anoplura) in (C) have fragmented mt genomes with multiple minichromosomes. The human head louse, Pe. h. capitis, was not included in (C) because it has identical sequences with the human body louse, Pe. h. humanus, for trnL1 and trnL2 genes.
Mentions: We used distance-based neighbor-joining (NJ) method to analyze the sequences of trnL1(tag) and trnL2(taa) genes. The NJ tree showed that these two genes evolved independently in a wide range of species of mammals and insects that have the typical single-chromosome mt genome organization. As would be expected for any pair of homologous genes, trnL1(tag) of a given species was more closely related to trnL1(tag) of other species than it is to trnL2(taa) of its own, and vice versa (Fig. 4A,B; Alignment S3 and S4). In the elephant lice and the sucking lice that have fragmented mt genomes, however, both independent evolution and concerted evolution were observed between the two tRNA genes for leucine (Fig. 4C; Alignment S5). In the two species of pig lice, Haematopinus suis and Haematopinus apri, both trnL genes evolved independently: trnL1(tag) genes of the two species are most closely related to each other whereas trnL2(tag) genes of the two species are most closely related. In the elephant louse, the human lice and the rat louse, Po. spinulosa, however, the two trnL genes evolved in concert: trnL1(tag) of each species is more closely related to trnL2(taa) of the same species than to trnL1(tag) of other species, and vice versa.

Bottom Line: 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.Each minichromosome is 3.5-4.2 kb in size and has 2-6 genes.Our results indicate that mt genome fragmentation is shared by the suborders Anoplura and Rhynchophthirina.

View Article: PubMed Central - PubMed

Affiliation: GeneCology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4556, Australia.

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.

No MeSH data available.


Related in: MedlinePlus