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Mesostigmata is an extremely diverse group of mites with more than 11,000 described species in 109 families. The complete mitochondrial (mt) genomes of five species of mesostigmatid mites from three families (Varroidae, Ologamasidae, Phytoseiidae) have been reported previously; all of them are rearranged or highly rearranged in gene order. However, it is unclear when mt genome reorganization occurred and how common it is in mesostigmatid mites. We sequenced the mt genomes of ten species of mesostigmatid mites from five more families (Blattisociidae, Diplogyniidae, Laelapidae, Macrochelidae, Parasitidae). We found that species in the families Diplogyniidae and Parasitidae have retained the ancestral mt genome organization of arthropods, which is in stark contrast to the highly rearranged mt genomes in the Phytoseiidae species. As in the Varroidae and Ologamasidae species, the mt genomes of the Blattisociidae, Macrochelidae and Laelapidae species are also rearranged but are less rearranged than in the Phytoseiidae species. Each of the six mesostigmatid families that have rearranged mt genomes is characterized by unique gene order not seen in other mesostigmatid families. Furthermore, the mt genome organization also differs among three genera of the Phytoseiidae, between two genera of the Laelapidae, and among three Macrocheles species of the Macrochelidae. Our results indicate that: (a) the most recent common ancestor of mesostigmatid mites likely retained the ancestral mt genome organization of arthropods; and (b) mt genome organization characterizes various lineages of mesostigmatid mites and provides a valuable source of information for understanding their phylogeny and evolution. [ABSTRACT FROM AUTHOR]

We used entire mitochondrial (mt) genome sequences (14.5–15 kbp) to resolve the phylogeny of the four main lineages of the Haematobothrion ticks: Alloceraea, Archaeocroton, Bothriocroton and Haemaphysalis. In our phylogenetic trees, Alloceraea was the sister to Archaeocroton sphenodonti, a tick of an archetypal reptile, the tuatara, from New Zealand, to the exclusion of the rest of the species of Haemaphysalis. The mt genomes of all four of the Alloceraea species that have been sequenced so far had a substantial insert, 132–312 bp, between the tRNA‐Glu (E) gene and the nad1 gene in their mt genomes. This insert was not found in any of the other eight subgenera of Haemaphysalis. The mt genomes of 13 species of Haemaphysalis from NCBI GenBank were added to the most recent data set on Haemaphysalis and its close relatives to help resolve the phylogeny of Haemaphysalis, including five new subgenera of Haemaphysalis not previously considered by other authors: Allophysalis (structurally primitive), Aboimisalis (structurally primitive), Herpetobia (structurally intermediate), Ornithophysalis (structurally advanced) and Segalia (structurally advanced). We elevated Alloceraea Schulze, 1919 to the status of genus because Alloceraea Schulze, 1919 is phylogenetically distinct from the other subgenera of Haemaphysalis. Moreover, we propose that the subgenus Allophysalis is the sister to the rest of the Haemaphysalis (14 subgenera) and that the 'structurally primitive' subgenera Hoogstraal and Kim comprise early diverging lineages. Our matrices of the pairwise genetic difference (percent) of mt genomes and partial 16S rRNA sequences indicated that the mt genome sequence of Al. kitaokai (gb# OM368280) may not be Al. kitaokai Hoogstraal, 1969 but rather another species of Alloceraea. In a similar way, the mt genome sequence of H. (Herpetobia) nepalensis Hoogstraal, 1962 (gb# NC_064124) was only 2% genetically different to that of H. (Allophysalis) tibetensis Hoogstraal, 1965 (gb# OM368293): this indicates to us that they are the same species. Alloceraea cretacea may be better placed in a genus other than Alloceraea Schulze, 1919. Reptiles may have been the host to the most recent common ancestor of Archaeocroton and Alloceraea. [ABSTRACT FROM AUTHOR]

Background: Debilitating skin infestations caused by the mite, Sarcoptes scabiei, have a profound impact on human and animal health globally. In Australia, this impact is evident across different segments of Australian society, with a growing recognition that it can contribute to rapid declines of native Australian marsupials. Cross-host transmission has been suggested to play a significant role in the epidemiology and origin of mite infestations in different species but a chronic lack of genetic resources has made further inferences difficult. To investigate the origins and molecular epidemiology of S. scabiei in Australian wildlife, we sequenced the mitochondrial genomes of S. scabiei from diseased wombats (Vombatus ursinus) and koalas (Phascolarctos cinereus) spanning New South Wales, Victoria and Tasmania and compared them with the recently sequenced mitochondrial genome sequences of S. scabiei from humans. Results: We found unique S. scabiei haplotypes among individual wombat and koala hosts with high sequence similarity (99.1% - 100%). Phylogenetic analysis of near full-length mitochondrial genomes revealed three clades of S. scabiei (one human and two marsupial), with no apparent geographic or host species pattern, suggestive of multiple introductions. The availability of additional mitochondrial gene sequences also enabled a re-evaluation of a range of putative molecular markers of S. scabiei, revealing that cox1 is the most informative gene for molecular epidemiological investigations. Utilising this gene target, we provide additional evidence to support cross-host transmission between different animal hosts. Conclusions: Our results suggest a history of parasite invasion through colonisation of Australia from hosts across the globe and the potential for cross-host transmission being a common feature of the epidemiology of this neglected pathogen. If this is the case, comparable patterns may exist elsewhere in the 'New World'. This work provides a basis for expanded molecular studies into mange epidemiology in humans and animals in Australia and other geographic regions. [ABSTRACT FROM AUTHOR]

Fragmented mitochondrial (mt) genomes have been reported in 11 species of sucking lice (suborder Anoplura) that infest humans, chimpanzees, pigs, horses, and rodents. There is substantial variation among these lice in mt karyotype: the number of minichromosomes of a species ranges from 9 to 20; the number of genes in a minichromosome ranges from 1 to 8; gene arrangement in a minichromosome differs between species, even in the same genus. We sequenced the mt genome of the guanaco louse, Microthoracius praelongiceps, to help establish the ancestral mt karyotype for sucking lice and understand how fragmented mt genomes evolved. The guanaco louse has 12 mt minichromosomes; each minichromosome has 2-5 genes and a non-coding region. The guanaco louse shares many features with rodent lice in mt karyotype, more than with other sucking lice. The guanaco louse, however, is more closely related phylogenetically to human lice, chimpanzee lice, pig lice, and horse lice than to rodent lice. By parsimony analysis of shared features in mt karyotype, we infer that the most recent common ancestor of sucking lice, which lived ~75 Ma, had 11 minichromosomes; each minichromosome had 1-6 genes and a non-coding region. As sucking lice diverged, split of mt minichromosomes occurred many times in the lineages leading to the lice of humans, chimpanzees, and rodents whereas merger of minichromosomes occurred in the lineage leading to the lice of pigs and horses. Together, splits and mergers of minichromosomes created a very complex and dynamic mt genome organization in the sucking lice. [ABSTRACT FROM AUTHOR]

Colon cancer is one of the most common cancers worldwide with high mortality. A major issue in colon cancer treatment is drug-resistance and metastasis that have been ascribed to the cancer stem cells. In this study, colon cancer stem cells were isolated through sphere culture and verified with the cancer stem cell markers CD133, CD44, and CD24. It was demonstrated that the PI3K/Akt/mTOR signalling pathway was highly activated in the colon cancer stem cells and that inhibition of the PI3K/Akt/mTOR pathway by the inhibitor BEZ235 suppressed the colon cancer stem cell proliferation with reduced stemness indicated by CD133 and Lgr5 expressions. Treatment with insulin as a known activator of the PI3K/Akt pathway increased CD133 expression and decreased the effects of BEZ235 on colon cancer proliferation and survival. The data presented here collectively suggest that the PI3K/Akt/ mTOR pathway underpins the stemness of colon cancer stem cells and BEZ235 is potentially a good drug candidate for treatment of colon cancer drug resistance and metastasis. [ABSTRACT FROM AUTHOR]

Highlights: [•] We sequenced the entire or partial mitochondrial genomes of five species of Rhipicephlus (Boophilus). [•] We also sequenced the entire mitochondrial genomes of three specimens of R. microplus from Brazil, Cambodia, and China. [•] Our analyses suggest that R. microplus from China and India are a cryptic species. [•] Aditionally, we assessed the phylogenetic resolution within the R. microplus complex of: cox1, ITS2, 12S and 16S rRNA. [•] Of these four common markers, cox1 and 16S rRNA have the best phylogenetic resolution within the R. microplus complex. [ABSTRACT FROM AUTHOR]

The superorder Psocodea has ∼10,000 described species in two orders: Psocoptera (barklice and booklice) and Phthiraptera (parasitic lice). One booklouse, Liposcelis bostrychophila and six species of parasitic lice have been sequenced for complete mitochondrial (mt) genomes; these seven species have the most rearranged mt genomes seen in insects. The mt genome of a barklouse, lepidopsocid sp., has also been sequenced and is much less rearranged than those of the booklouse and the parasitic lice. To further understand mt gene rearrangements in the Psocodea, we sequenced the mt genomes of two barklice, Psococerastis albimaculata and Longivalvus hyalospilus, the first representatives from the suborder Psocomorpha, which is the most species-rich suborder of the Psocodea. We found that these two barklice have the least rearranged mt genomes seen in the Psocodea to date: a protein-coding gene (nad3) and five tRNAs (trnN, trnS1, trnE, trnM and trnC) have translocated. Rearrangements of mt genes in these two barklice can be accounted for by two events of tandem duplication followed by random deletions. Phylogenetic analyses of the mt genome sequences support the view that Psocoptera is paraphyletic whereas Phthiraptera is monophyletic. The booklouse, L. bostrychophila (suborder Troctomorpha) is most closely related to the parasitic lice. The barklice (suborders Trogiomorpha and Psocomorpha) are closely related and form a monophyletic group. We conclude that mt gene rearrangement has been substantially faster in the lineage leading to the booklice and the parasitic lice than in the lineage leading to the barklice. Lifestyle change appears to be associated with the contrasting rates in mt gene rearrangements between the two lineages of the Psocodea. [ABSTRACT FROM AUTHOR]

Bilateral animals are featured by an extremely compact mitochondrial (mt) genome with 37 genes on a single circular chromosome. The human body louse, Pediculus humanus, however, has its mt genes on 20 minichromosomes. We sequenced the mt genomes of two other human lice: the head louse, P. capitis, and the pubic louse, Pthirus pubis. Comparison among the three human lice revealed the presence of fragmented mt genomes in their most recent common ancestor, which lived ∼7 Ma. The head louse has exactly the same set of mt minichromosomes as the body louse, indicating that the number of minichromosomes, and the gene content and gene arrangement in each minichromosome have remained unchanged since the body louse evolved from the head louse ∼107,000 years ago. The pubic louse has the same pattern of one protein-coding or rRNA gene per minichromosome (except one minichromosome with two protein-coding genes, atp6 and atp8) as the head louse and the body louse. This pattern is apparently ancestral to all human lice and has been stable for at least 7 Myr. Most tRNA genes of the pubic louse, however, are on different minichromosomes when compared with their counterparts in the head louse and the body louse. It is evident that rearrangement of four tRNA genes (for leucine, arginine and glycine) was due to gene-identity switch by point mutation at the third anticodon position or by homologous recombination, whereas rearrangement of other tRNA genes was by gene translocation between minichromosomes, likely caused by minichromosome split via gene degeneration and deletion. [ABSTRACT FROM AUTHOR]

Bilateral animals are featured by an extremely compact mitochondrial (mt) genome with 37 genes on a single circular chromosome. The human body louse, Pediculus humanus, however, has its mt genes on 20 minichromosomes. We sequenced the mt genomes of two other human lice: the head louse, P. capitis, and the pubic louse, Pthirus pubis. Comparison among the three human lice revealed the presence of fragmented mt genomes in their most recent common ancestor, which lived ∼7 Ma. The head louse has exactly the same set of mt minichromosomes as the body louse, indicating that the number of minichromosomes, and the gene content and gene arrangement in each minichromosome have remained unchanged since the body louse evolved from the head louse ∼107,000 years ago. The pubic louse has the same pattern of one protein-coding or rRNA gene per minichromosome (except one minichromosome with two protein-coding genes, atp6 and atp8) as the head louse and the body louse. This pattern is apparently ancestral to all human lice and has been stable for at least 7 Myr. Most tRNA genes of the pubic louse, however, are on different minichromosomes when compared with their counterparts in the head louse and the body louse. It is evident that rearrangement of four tRNA genes (for leucine, arginine and glycine) was due to gene-identity switch by point mutation at the third anticodon position or by homologous recombination, whereas rearrangement of other tRNA genes was by gene translocation between minichromosomes, likely caused by minichromosome split via gene degeneration and deletion. [ABSTRACT FROM AUTHOR]

Abstract: Our understanding of the phylogenetic relationships among tick lineages has been limited by the lack of resolution provided by the most commonly used phylogenetic markers. Mitochondrial genomes are increasingly used to address controversial phylogenetic relationships. To date, the complete mitochondrial genomes of eleven tick species have been sequenced; however, only three of these species are metastriate ticks, the most speciose lineage of ticks. In this study, we present the nucleotide sequences of the complete mitochondrial genomes of five more species of metastriate ticks: Amblyomma elaphense, Amblyomma fimbriatum, Amblyomma sphenodonti, Bothriocroton concolor and Bothriocroton undatum. We use complete mitochondrial genome sequences to address the phylogenetic placement of two morphologically ‘primitive’ species –Am. elaphense and Am. sphenodonti – with respect to the genus Amblyomma. Our analysis of these five mitochondrial genomes with the other eleven tick mitochondrial genomes, as well as analysis of nuclear rRNA genes, provides strong evidence that the genus Amblyomma is polyphyletic with the inclusion of Am. sphenodonti and Am. elaphense. A new genus or two new genera may be required to describe Am. sphenodonti and Am. elaphense. It is also possible that these two species are sisters to two established genera, Bothriocroton in the case of Am. sphenodonti, and Haemaphysalis in the case of Am. elaphense. However, other arrangements of these taxa cannot be excluded with the current data. Thus, while Am. sphenodonti and Am. elaphense do not belong in the genus Amblyomma, the phylogenetic placement of these two species cannot be resolved without more data from metastriate ticks, either greater sampling of mitochondrial genomes, or a large data set of nuclear genes. [Copyright &y& Elsevier]

Abstract: We inferred the phylogenetic and phylogeographic relationships in ticks, which were identified morphologically as Ixodes holocyclus and Ixodes cornuatus, from mitochondrial cytochrome oxidase subunit 1 (COX1) and nuclear internal transcribed spacer 2 (ITS2) sequences. We obtained COX1 (640bp) and ITS2 (527–568bp) sequences from 429 ticks from 49 localities in Tasmania, Victoria, New South Wales and Queensland, Australia. Our analyses show that there are two species of Ixodes in eastern Australia that cause paralysis in dogs and other mammals: I. holocyclus and I. cornuatus. Further, we conclude that the morphological criteria used to differentiate female I. holocyclus and I. cornuatus are equivocal but I. holocyclus can be distinguished from I. cornuatus using COX1 and/or ITS2 sequences. Intraspecific genetic variation in I. holocyclus and I. cornuatus was less than 0.86% and 0.19% for COX1 and ITS2, respectively. Ixodes holocyclus could be genetically distinguished between different geographic ranges. There were no significant genetic differences between I. cornuatus from Tasmania and mainland Australia, but there are some COX1 haplotypes of I. cornuatus from the mainland that were not detected in Tasmanian and vice versa. [Copyright &y& Elsevier]

Abstract: The mitochondrial (mt) genome of the human body louse, Pediculus humanus, consists of 18 minichromosomes. Each minichromosome is 3 to 4kb long and has 1 to 3 genes. There is unequivocal evidence for recombination between different mt minichromosomes in P. humanus. It is not known, however, how these minichromosomes recombine. Here, we report the discovery of eight chimeric mt minichromosomes in P. humanus. We classify these chimeric mt minichromosomes into two groups: Group I and Group II. Group I chimeric minichromosomes contain parts of two different protein-coding genes that are from different minichromosomes. The two parts of protein-coding genes in each Group I chimeric minichromosome are joined at a microhomologous nucleotide sequence; microhomologous nucleotide sequences are hallmarks of non-homologous recombination. Group II chimeric minichromosomes contain all of the genes and the non-coding regions of two different minichromosomes. The conserved sequence blocks in the non-coding regions of Group II chimeric minichromosomes resemble the “recombination repeats” in the non-coding regions of the mt genomes of higher plants. These repeats are essential to homologous recombination in higher plants. Our analyses of the nucleotide sequences of chimeric mt minichromosomes indicate both homologous and non-homologous recombination between minichromosomes in the mitochondria of the human body louse. [Copyright &y& Elsevier]

The gene content of a mitochondrial (mt) genome, i.e., 37 genes and a large noncoding region ( LNR), is usually conserved in Metazoa. The arrangement of these genes and the LNR is generally conserved at low taxonomic levels but varies substantially at high levels. We report here a variation in mt gene content and gene arrangement among chigger mites of the genus Leptotrombidium. We found previously that the mt genome of Leptotrombidium pallidum has an extra gene for large-subunit rRNA ( rrnL), a pseudo-gene for small-subunit rRNA ( PrrnS), and three extra LNRs, additional to the 37 genes and an LNR typical of Metazoa. Further, the arrangement of mt genes of L. pallidum differs drastically from that of the hypothetical ancestor of the arthropods. To find to what extent the novel gene content and gene arrangement occurred in Leptotrombidium, we sequenced the entire or partial mt genomes of three other species, L. akamushi, L. deliense, and L. fletcheri. These three species share the arrangement of all genes with L. pallidum, except trnQ (for tRNA-glutamine). Unlike L. pallidum, however, these three species do not have extra rrnL or PrrnS and have only one extra LNR. By comparison between Leptotrombidium species and the ancestor of the arthropods, we propose that (1) the type of mt genome present in L. pallidum evolved from the type present in the other three Leptotrombidium species, and (2) three molecular mechanisms were involved in the evolution of mt gene content and gene arrangement in Leptotrombidium species. [ABSTRACT FROM AUTHOR]

To better understand the evolution of mitochondrial (mt) genomes in the Acari (mites and ticks), we sequenced the mt genome of the chigger mite, Leptotrombidium pallidum (Arthropoda: Acari: Acariformes). This genome is highly rearranged relative to that of the hypothetical ancestor of the arthropods and the other species of Acari studied. The mt genome of L. pallidum has two genes for large subunit rRNA, a pseudogene for small subunit rRNA, and four nearly identical large noncoding regions. Nineteen of the 22 tRNAs encoded by this genome apparently lack either a T-arm or a D-arm. Further, the mt genome of L. pallidum has two distantly separated sections with identical sequences but opposite orientations of transcription. This arrangement cannot be accounted for by homologous recombination or by previously known mechanisms of mt gene rearrangement. The most plausible explanation for the origin of this arrangement is illegitimate inter-mtDNA recombination, which has not been reported previously in animals. In light of the evidence from previous experiments on recombination in nuclear and mt genomes of animals, we propose a model of illegitimate inter-mtDNA recombination to account for the novel gene content and gene arrangement in the mt genome of L. pallidum. [ABSTRACT FROM AUTHOR]

The over 4,100 species of bird lice are classified into 214 genera in the parvorders Amblycera and Ischnocera. Congeneric species of bird lice usually share much similarity in morphology and in mitochondrial (mt) genome organization. Two recent studies, however, reported substantial intra-genus variation in mt genome organization in bird lice. Both the ancestral single-chromosome mt genome and a fragmented mt genome with two or three minichromosomes were observed in the genera Austromenopon and Laemobothrion. To better understand intra-genus variation in mt genome organization, we sequenced the complete mt genome of the white spoonbill louse Ibidoecus plataleae and compared it with that of the glossy ibis feather louse Ibidoecus bisignatus reported previously. We found that I. plataleae had a fragmented mt genome with 12 minichromosomes; each minichromosome was 2,798 to 3,628 bp in size and had 2 to 6 genes. This is in stark contrast to the mt genome of I. bisignatus, which has all genes on a single chromosome, 14,909 bp in size. This is the most drastic intra-genus variation in mt genome organization observed to date in animals, indicating an unprecedented rapid process of mt genome fragmentation in the genus Ibidoecus. The divergence time between I. plataleae and I. bisignatus is currently unknown but is estimated to be less than 23 million years. Either many minichromosal split events occurred after I. plataleae diverged from I. bisignatus, or one minichromosome splits into multiple minichromosomes in a single event. Sequencing and comparing more Ibidoecusi species will help understand the unusual mt genome fragmentation in this genus. [ABSTRACT FROM AUTHOR]

Birds can act as successful long‐distance vectors and reservoirs for numerous zoonotic bacterial, parasitic and viral pathogens, which can be a concern given the interconnectedness of animal, human and environmental health. Examples of such avian pathogens are members of the genus Chlamydia. Presently, there is a lack of research investigating chlamydial infections in Australian wild and captive birds and the subsequent risks to humans and other animals. In our current study, we investigated the prevalence and genetic diversity of chlamydial organisms infecting wild birds from Queensland and the rate of co‐infections with beak and feather disease virus (BFDV). We screened 1114 samples collected from 564 different birds from 16 orders admitted to the Australia Zoo Wildlife Hospital from May 2019 to February 2021 for Chlamydia and BFDV. Utilizing species‐specific quantitative polymerase chain reaction (qPCR) assays, we revealed an overall Chlamydiaceae prevalence of 29.26% (165/564; 95% confidence interval (CI) 25.65–33.14), including 3.19% (18/564; 95% CI 2.03–4.99%) prevalence of the zoonotic Chlamydia psittaci. Chlamydiaceae co‐infection with BFDV was detected in 9.75% (55/564; 95% CI 7.57–12.48%) of the birds. Molecular characterization of the chlamydial 16S rRNA and ompA genes identified C. psittaci, in addition to novel and other genetically diverse Chlamydia species: avian Chlamydia abortus, Ca. Chlamydia ibidis and Chlamydia pneumoniae, all detected for the first time in Australia within a novel avian host range (crows, figbirds, herons, kookaburras, lapwings and shearwaters). This study shows that C. psittaci and other emerging Chlamydia species are prevalent in a wider range of avian hosts than previously anticipated, potentially increasing the risk of spill‐over to Australian wildlife, livestock and humans. Going forward, we need to further characterize C. psittaci and other emerging Chlamydia species to determine their exact genetic identity, potential reservoirs, and factors influencing infection spill‐over. [ABSTRACT FROM AUTHOR]

Background: The mitochondrial (mt) genomes of 15 species of sucking lice from seven families have been studied to date. These louse species have highly dynamic, fragmented mt genomes that differ in the number of minichromosomes, the gene content, and gene order in a minichromosome between families and even between species of the same genus. Results: In the present study, we analyzed the publicly available data to understand mt genome fragmentation in seal lice (family Echinophthiriidae) and gorilla louse, Pthirus gorillae (family Pthiridae), in particular the role of minichromosome split and minichromosome merger in the evolution of fragmented mt genomes. We show that 1) at least three ancestral mt minichromosomes of sucking lice have split in the lineage leading to seal lice, 2) one minichromosome ancestral to primate lice has split in the lineage to the gorilla louse, and 3) two ancestral minichromosomes of seal lice have merged in the lineage to the northern fur seal louse. Minichromosome split occurred 15-16 times in total in the lineages leading to species in six families of sucking lice investigated. In contrast, minichromosome merger occurred only four times in the lineages leading to species in three families of sucking lice. Further, three ancestral mt minichromosomes of sucking lice have split multiple times independently in different lineages of sucking lice. Our analyses of mt karyotypes and gene sequences also indicate the possibility of a host switch of crabeater seal louse to Weddell seals. Conclusions: We conclude that: 1) minichromosome split contributes more than minichromosome merger in mt genome fragmentation of sucking lice, and 2) mt karyotype comparison helps understand the phylogenetic relationships between sucking louse species. [ABSTRACT FROM AUTHOR]

Background: Ixodes barkeri, a tick with a distinctive ventrolateral horn-like projection on palpal segment 1, was described in 2019 from two male ticks from the Wet Tropics of Far North Queensland, Australia. However, females lie at the core of the taxonomy and subgenus classification of Ixodes; hence, we sought specimens of female ticks, successfully recovering females, plus nymphs and larvae. Mitochondrial genomes are also desirable additions to the descriptions of species of ticks particularly regarding subgenus systematics. So, we sequenced the mt genomes of I. barkeri Barker, 2019, and the possible relatives of I. barkeri that were available to us (I. australiensis Neumann, 1904, I. fecialis Warburton & Nuttall, 1909, and I. woyliei Ash et al. 2017) with a view to discovering which if any of the subgenera of Ixodes would be most suitable for I. barkeri Barker, 2019. Results: The female, nymph, larva and mitochondrial genome of Ixodes barkeri Barker, 2019, are described for the first time and the male of I. barkeri is redescribed in greater detail than previously. So far, I. barkeri is known only from a monotreme, the short-beaked echidna, Tachyglossus aculeatus (Shaw, 1792), from the highland rainforests of the Wet Tropics of Far North Queensland, Australia. Conclusions: Our phylogeny from entire mitochondrial genomes indicated that I. barkeri and indeed I. woyliei Ash et al., 2017, another tick that was described recently, are best placed in the subgenus Endopalpiger Schulze, 1935. [ABSTRACT FROM AUTHOR]

Background: Hemiptera is the fifth species-rich order of insects and the most species-rich order of hemimetabolous insects, including numerous insect species that are of agricultural or medical significance. Despite much effort and recent advance in inferring the Hemiptera phylogeny, some high-level relationships among superfamilies remain controversial. Results: We sequenced the genomes of 64 hemipteran species from 15 superfamilies and the transcriptomes of two additional scale insect species, integrating them with existing genomic and transcriptomic data to conduct a comprehensive phylogenetic analysis of Hemiptera. Our datasets comprise an average of 1625 nuclear loci of 315 species across 27 superfamilies of Hemiptera. Our analyses supported Cicadoidea and Cercopoidea as sister groups, with Membracoidea typically positioned as the sister to Cicadoidea + Cercopoidea. In most analyses, Aleyrodoidea was recovered as the sister group of all other Sternorrhyncha. A sister-group relationship was supported between Coccoidea and Aphidoidea + Phylloxeroidea. These relationships were further supported by four-cluster likelihood mapping analyses across diverse datasets. Our ancestral state reconstruction indicates phytophagy as the primary feeding strategy for Hemiptera as a whole. However, predation likely represents an ancestral state for Heteroptera, with several phytophagous lineages having evolved from predatory ancestors. Certain lineages, like Lygaeoidea, have undergone a reversal transition from phytophagy to predation. Our divergence time estimation placed the diversification of hemipterans to be between 60 and 150 million years ago. Conclusions: By expanding phylogenomic taxon sampling, we clarified the superfamily relationships within the infraorder Cicadomorpha. Our phylogenetic analyses supported the sister-group relationship between the superfamilies Cicadoidea and Cercopoidea, and the superfamily Membracoidea as the sister to Cicadoidea + Cercopoidea. Our divergence time estimation supported the close association of hemipteran diversification with the evolutionary success and adaptive radiation of angiosperms during the Cretaceous period. [ABSTRACT FROM AUTHOR]

Bovicola ovis, commonly known as the sheep-biting louse, is an ectoparasite that adversely affects the sheep industry. Sheep louse infestation lowers the quality of products, including wool and leather, causing a loss of approximately AUD 123M per annum in Australia alone. The lack of a high-quality genome assembly for the sheep-biting louse, as well as any closely related livestock lice, has hindered the development of louse research and management control tools. In this study, we present the assembly of B. ovis with a genome size of ~123 Mbp based on a nanopore long-read sequencing library and Illumina RNA sequencing, complemented with a chromosome-level scaffolding using the Pore-C multiway chromatin contact dataset. Combining multiple alignment and gene prediction tools, a comprehensive annotation on the assembled B. ovis genome was conducted and recalled 11,810 genes as well as other genomic features including orf, ssr, rRNA and tRNA. A manual curation using alignment with the available closely related louse species, Pediculus humanus, increased the number of annotated genes to 16,024. Overall, this study reported critical genetic resources and biological insights for the advancement of sheep louse research and the development of sustainable control strategies in the sheep industry. [ABSTRACT FROM AUTHOR]

Background: There is a high incidence of cervical cancer in Xinjiang. Genetic variation in human papillomavirus may increase its ability to invade, spread, and escape host immune response. Methods: HPV16 genome was sequenced for 90 positive samples of HPV16 infection. Sequences of the E4, E5 and L2 genes were analysed to reveal sequence variation of HPV16 in Xinjiang and the distribution of variation among the positive samples of HPV16 infection. Results: Eighty-one of the 90 samples of HPV16 infection showed variation in HPV16 E4 gene with 18 nucleotide variation sites, of which 8 sites were synonymous variations and 11 missense variations. 90 samples of HPV16 infection showed variation in HPV16 E5 and L2 genes with 16 nucleotide variation sites (6 synonymous, 11 missense variations) in the E5 gene and 100 nucleotide variation sites in L2 gene (37 synonymous, 67 missense variations). The frequency of HPV16 L2 gene missense variations G3377A, G3599A, G3703A, and G3757A was higher in the case groups than in the control groups. Conclusions: Phylogenetic tree analysis showed that 87 samples were European strains, 3 cases were Asian strains, there were no other variations, and G4181A was related to Asian strains. HPV16 L2 gene missense variations G3377A, G3599A, G3703A, and G3757A were significantly more frequent in the case groups than in the control groups. [ABSTRACT FROM AUTHOR]

Background: Historical European exploration and colonization resulted in the introduction of four species of rodents to the Australian continent from Eurasia: the brown rat, Rattus norvegicus, the black rat, R. rattus, the Pacific rat, R. exulans, and the house mouse, Mus musculus. The spread of these rodents created opportunities for their co-introduced sucking lice to parasitize and adapt to endemic rodents in Australia. Methods: We collected sucking lice from rodent specimens in seven museums across Australia. We identified the spiny rat louse, Polyplax spinulosa, based on morphology. We sequenced the mitochondrial cox1 and rrnL genes of P. spinulosa specimens and constructed a phylogenetic tree with rrnL sequences. Results: We examined 989 rodent specimens of 54 species and collected 2111 adult sucking lice and 1064 nymphal sucking lice. We found that P. spinulosa had nearly doubled its host range by parasitizing at least six endemic rodent species in Australia. The other two introduced lice, P. serrata and Hoplopleura pacifica, however, have apparently failed to expand to any endemic rodents in Australia. Our analysis of mitochondrial rrnL gene sequences divided P. spinulosa into two genotypes (European vs Southeast Asian), which differ by 7.5%; both genotypes were introduced into Australia and then expanded their host ranges to include endemic rodents. Conclusions: The earliest record of a European ship landing in Australia was in 1606, followed by British settlement in 1788. The expansion of P. spinulosa to at least six endemic rodent species in Australia has therefore occurred in the time frame of 200 to 400 years, which is extremely rapid relative to its host expansion to eight native rat species in Eurasia in ~ 16 million years since it diverged from P. serrata. The host expansion of P. spinulosa is remarkable for a blood-sucking louse and is in stark contrast to the absence of host expansion by P. serrata and H. pacifica. Comparison among these three introduced sucking lice indicated that both louse-specific factors and host-specific factors can contribute to the success or failure of host expansion. [ABSTRACT FROM AUTHOR]

Background: Eriophyoid mites (Eriophyoidea) are among the largest groups in the Acariformes; they are strictly phytophagous. The higher-level phylogeny of eriophyoid mites, however, remains unresolved due to the limited number of available morphological characters—some of them are homoplastic. Nevertheless, the eriophyoid mites sequenced to date showed highly variable mitochondrial (mt) gene orders, which could potentially be useful for resolving the higher-level phylogenetic relationships. Results: Here, we sequenced and compared the complete mt genomes of 153 eriophyoid mite species, which showed 54 patterns of rearranged mt gene orders relative to that of the hypothetical ancestor of arthropods. The shared derived mt gene clusters support the monophyly of eriophyoid mites (Eriophyoidea) as a whole and the monophylies of six clades within Eriophyoidea. These monophyletic groups and their relationships were largely supported in the phylogenetic trees inferred from mt genome sequences as well. Our molecular dating results showed that Eriophyoidea originated in the Triassic and diversified in the Cretaceous, coinciding with the diversification of angiosperms. Conclusions: This study reveals multiple molecular synapomorphies (i.e. shared derived mt gene clusters) at different levels (i.e. family, subfamily or tribe level) from the complete mt genomes of 153 eriophyoid mite species. We demonstrated the use of derived mt gene clusters in unveiling the higher-level phylogeny of eriophyoid mites, and underlines the origin of these mites and their co-diversification with angiosperms. [ABSTRACT FROM AUTHOR]

The parvorder Rhynchopthirina contains three currently recognised species of lice that parasitize elephants (both African savanna elephant Loxodonta africana and Asian elephant Elephas maximus), desert warthogs (Phacochoerus aethiopicus) and Red River hogs (Potamochoerus porcus), respectively. The Asian elephant lice and the African savanna elephant lice are currently treated as the same species, Haematomyzus elephantis (Piaget, 1869), based on morphology despite the fact that their hosts diverged 8.4 million years ago. In the current study, we sequenced 23 mitochondrial (mt) genes of African savanna elephant lice collected in South Africa and analysed the sequence divergence between African savanna elephant lice and previously sequenced Asian elephant lice. Sequence comparisons revealed >23% divergence for the 23 mt genes as a whole and ~17% divergence for cox1 gene between African savanna and Asian elephant lice, which were far higher than the divergence expected within a species. Furthermore, the mt gene sequence divergences between these lice are 3.76–4.6 times higher than that between their hosts, the African savanna and Asian elephants, which are expected for the co‐divergence and co‐evolution between lice and their elephant hosts. We conclude that (1) H. elephantis (Piaget, 1869) contains cryptic species and (2) African savanna and Asian elephant lice are different species genetically that may have co‐diverged and co‐evolved with their hosts. [ABSTRACT FROM AUTHOR]

Human gnathostomiasis is an emerging food-borne parasitic disease caused by nematodes in the genus Gnathostoma. In spite of their significance as pathogens, these parasites remain poorly understood at the molecular level. In the present study, we sequenced the mitochondrial (mt) genome of G. spinigerum, which infects a range of definitive hosts including dogs, cats, tigers, leopards and humans. The mt genome of G. spinigerum is 14,079 bp in size and shows substantial changes in gene order compared to other nematodes studied to date. Phylogenetic analyses of mt genome sequences by Bayesian inference (BI) revealed that the infraorder Gnathostomatomorpha (represented by G. spinigerum) is closely related to the infraorder Ascaridomorpha. G. spinigerum is the first species from the infraorder Gnathostomatomorpha for which a complete mt genome has been sequenced. The new data will help understand the evolution, population genetics and systematics of this medically important group of parasites. [ABSTRACT FROM AUTHOR]

Mitochondrial (mt) genome data have been proven to be informative for animal phylogenetic studies but may also suffer from systematic errors, due to the effects of accelerated substitution rate and compositional heterogeneity. We analyzed the mt genomes of 25 insect species from the four paraneopteran orders, aiming to better understand how accelerated substitution rate and compositional heterogeneity affect the inferences of the higher-level phylogeny of this diverse group of hemimetabolous insects. We found substantial heterogeneity in base composition and contrasting rates in nucleotide substitution among these paraneopteran insects, which complicate the inference of higher-level phylogeny. The phylogenies inferred with concatenated sequences of mt genes using maximum likelihood and Bayesian methods and homogeneous models failed to recover Psocodea and Hemiptera as monophyletic groups but grouped, instead, the taxa that had accelerated substitution rates together, including Sternorrhyncha (a suborder of Hemiptera), Thysanoptera, Phthiraptera and Liposcelididae (a family of Psocoptera). Bayesian inference with nucleotide sequences and heterogeneous models (CAT and CAT + GTR), however, recovered Psocodea, Thysanoptera and Hemiptera each as a monophyletic group. Within Psocodea, Liposcelididae is more closely related to Phthiraptera than to other species of Psocoptera. Furthermore, Thysanoptera was recovered as the sister group to Hemiptera. [ABSTRACT FROM AUTHOR]

Background: Cervical cancer is a common gynecological malignancy. Gene microarray found that TCP11 gene was highly expressed in cervical cancer. However, the effect of TCP11 gene on the proliferation, apoptosis and migration of cervical cancer cells and its underlying molecular mechanisms are unclear. Methods: GEPIA database, tissue microarray, western blot and qRT-PCR were used to analyze the expression of TCP11 gene in cervical cancer tissues and cells and its relationship with patients’ survival rate. The cell cycle and apoptosis were detected by flow cytometry, and the expressions of cell cycle and apoptosis related molecules and EMT-related molecules were detected by Western blot and qRT-PCR. Results: The results showed that TCP11 gene was highly expressed in cervical cancer tissues and cells compared with normal cervical tissues and cells, and its expression was positively correlated with patients’ survival rate. The results of proliferation and migration assays showed that TCP11 overexpression inhibited the proliferation and migration of HeLa and SiHa cells. The results showed that TCP11 overexpression blocked the cell cycle of HeLa and SiHa cells, decreased the expression of CDK1 and Cyclin B1, and increased the apoptosis and the expression of caspase-3, cleaved-caspase-3 and cleaved-PARP. TCP11 overexpression increased the protein and mRNA expression of EMT-related molecules ZO-1 and E-cadherin. Conversely, TCP11 knockdown promoted the proliferation of HeLa and SiHa cells and the migration of HeLa cells. Conclusions: TCP11 overexpression significantly inhibited the occurrence and development of cervical cancer cells, it may be a potentially beneficial biomarker for cervical cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: To understand mitochondrial genome fragmentation in bird lice, we sequenced the mitochondrial genomes of 17 species of bird lice in the families Menoponidae and Laemobothriidae. Of the 17 species, four species of Menoponidae have fragmented mitochondrial genomes, whereas the other 13 species of both Menoponidae and Laemobothriidae retain the typical single-chromosome mitochondrial genomes. Our phylogenetic analyses showed that mitochondrial genome fragmentation occurred multiple times independently in these two families. We also found derived mitochondrial minichromosomal characters shared between bird lice in the same genus and among different genera. We conclude that while mitochondrial genome fragmentation as a general feature does not unite all the parasitic lice that have this feature, each independent mitochondrial genome fragmentation event may produce shared derived mitochondrial minichromosomal characters that can be useful for resolving the phylogeny of parasitic lice at different taxonomic levels. Mitochondrial (mt) genome fragmentation has been discovered in all five parvorders of parasitic lice (Phthiraptera). To explore whether minichromosomal characters derived from mt genome fragmentation are informative for phylogenetic studies, we sequenced the mt genomes of 17 species of bird lice in Menoponidae and Laemobothriidae (Amblycera). Four species of Menoponidae (Actornithophilus sp. 1 ex [pied oystercatcher], Act. sp. 2 ex [masked lapwing], Austromenopon sp. 2 ex [sooty tern and crested tern], Myr. sp. 1 ex [satin bowerbird]) have fragmented mt genomes, whereas the other 13 species retain the single-chromosome mt genomes. The two Actornithophilus species have five and six mt minichromosomes, respectively. Aus. sp. 2 ex [sooty tern and crested tern] has two mt minichromosomes, in contrast to Aus. sp. 1 ex [sooty shearwater], which has a single mt chromosome. Myr. sp. 1 ex [satin bowerbird] has four mt minichromosomes. When mapped on the phylogeny of Menoponidae and Laemobothriidae, it is evident that mt genome fragmentation has occurred multiple times independently among Menoponidae and Laemobothriidae species. We found derived mt minichromosomal characters shared between Myrsidea species, between Actornithophilus species, and between and among different ischnoceran genera, respectively. We conclude that while mt genome fragmentation as a general feature does not unite all the parasitic lice that have this feature, each independent mt genome fragmentation event does produce minichromosomal characters that can be informative for phylogenetic studies of parasitic lice at different taxonomic levels. [ABSTRACT FROM AUTHOR]

Background: Cervical cancer is currently estimated to be the fourth most common cancer among women worldwide and the leading cause of cancer-related deaths in some of the world's poorest countries. C/EBPβ has tumor suppressor effects because it is necessary for oncogene-induced senescence. However, C/EBPβ also has an oncogenic role. The specific role of C/EBPβ in cervical cancer as a tumor suppressor or oncoprotein is unclear. Objective: To explore the role of the C/EBPβ protein in cervical tumorigenesis and progression. Methods: Quantitative RT-PCR was used to analyze C/EBPβ (15 cervical cancer tissue samples and 15 corresponding normal cervical tissue samples), miR-661, and MTA1 mRNA expression in clinical samples (10 cervical cancer tissue samples and 10 corresponding normal cervical tissue samples). Immunohistochemistry was used to analyze C/EBPβ (381 clinical samples), Ki67 (80 clinical samples) and PCNA (60 clinical samples) protein expression. MALDI-TOF MassARRAY was used to analyze C/EBPβ gene methylation (13 cervical cancer tissues and 13 corresponding normal cervical tissues). Cell proliferation was analyzed by CCK-8 in cervical cancer cell lines. Western blotting and immunohistochemistry were performed to detect C/EBPβ protein expression levels, and mRNA expression was analyzed by quantitative RT-PCR analysis. Flow cytometry was performed to measure cell cycle distribution and cell apoptosis. Colony formation, Transwell, cell invasion, and wound healing assays were performed to detect cell migration and invasion. Results: C/EBPβ protein expression was significantly reduced in cervical cancer tissues compared with cervicitis tissues (P < 0.01). Ki67 protein and PCNA protein expression levels were significantly higher in cervical cancer tissues compared with cervicitis tissues. The rate of C/EBPβ gene promoter methylation of CpG12, 13, 14 and CpG19 in cervical cancer tissues was significantly increased compared with normal cervical tissue (P < 0.05). In addition, C/EBPβ was overexpressed in cervical cancer cells and this overexpression inhibited cell proliferation, migration, invasion, arrested cells in S phase, and promoted apoptosis. Conclusions: We have demonstrated that C/EBPβ decreased in cervical cancer tissues and overexpression of the C/EBPβ gene in cervical cancer cells could inhibit proliferation, invasion and migration. [ABSTRACT FROM AUTHOR]

Birds may act as hosts for numerous pathogens, including members of the family Chlamydiaceae, beak and feather disease virus (BFDV), avipoxviruses, Columbid alphaherpesvirus 1 (CoAHV1) and Psittacid alphaherpesvirus 1 (PsAHV1), all of which are a significant biosecurity concern in Australia. While Chlamydiaceae and BFDV have previously been detected in Australian avian taxa, the prevalence and host range of avipoxviruses, CoAHV1 and PsAHV1 in Australian birds remain undetermined. To better understand the occurrence of these pathogens, we screened 486 wild birds (kingfisher, parrot, pigeon and raptor species) presented to two wildlife hospitals between May 2019 and December 2021. Utilising various qPCR assays, we detected PsAHV1 for the first time in wild Australian birds (37/486; 7.61%), in addition to BFDV (163/468; 33.54%), Chlamydiaceae (98/468; 20.16%), avipoxviruses (46/486; 9.47%) and CoAHV1 (43/486; 8.85%). Phylogenetic analysis revealed that BFDV sequences detected from birds in this study cluster within two predominant superclades, infecting both psittacine and non-psittacine species. However, BFDV disease manifestation was only observed in psittacine species. All Avipoxvirus sequences clustered together and were identical to other global reference strains. Similarly, PsAHV1 sequences from this study were detected from a series of novel hosts (apart from psittacine species) and identical to sequences detected from Brazilian psittacine species, raising significant biosecurity concerns, particularly for endangered parrot recovery programs. Overall, these results highlight the high pathogen diversity in wild Australian birds, the ecology of these pathogens in potential natural reservoirs, and the spillover potential of these pathogens into novel host species in which these agents cause disease. [ABSTRACT FROM AUTHOR]

Background: Ticks (order Ixodida) are ectoparasites, vectors and reservoirs of many infectious agents affecting humans and domestic animals. However, the lack of information on tick genomic diversity leaves significant gaps in the understanding of the evolution of ticks and associated bacteria. Results: We collected > 20,000 contemporary and historical (up to 60 years of preservation) tick samples representing a wide range of tick biodiversity across diverse geographic regions in China. Metagenomic sequencing was performed on individual ticks to obtain the complete or near-complete mitochondrial (mt) genome sequences from 46 tick species, among which mitochondrial genomes of 23 species were recovered for the first time. These new mt genomes data greatly expanded the diversity of many tick groups and revealed five cryptic species. Utilizing the same metagenomic sequence data we identified divergent and abundant bacteria in Haemaphysalis, Ixodes, Dermacentor and Carios ticks, including nine species of pathogenetic bacteria and potentially new species within the genus Borrelia. We also used these data to explore the evolutionary relationship between ticks and their associated bacteria, revealing a pattern of long-term co-divergence relationship between ticks and Rickettsia and Coxiella bacteria. Conclusions: In sum, our study provides important new information on the genetic diversity of ticks based on an analysis of mitochondrial DNA as well as on the prevalence of tick-borne pathogens in China. It also sheds new light on the long-term evolutionary and ecological relationships between ticks and their associated bacteria. [ABSTRACT FROM AUTHOR]

Background: Blood-sucking lice in the genera Pediculus and Pthirus are obligate ectoparasites of great apes. Unlike most bilateral animals, which have 37 mitochondrial (mt) genes on a single circular chromosome, the sucking lice of humans have extensively fragmented mt genomes. The head louse, Pediculus capitis, and the body louse, Pe. humanus, have their 37 mt genes on 20 minichromosomes. The pubic louse, Pthirus pubis, has its 34 mt genes known on 14 minichromosomes. To understand the process of mt genome fragmentation in the sucking lice of great apes, we sequenced the mt genome of the chimpanzee louse, Pe. schaeffi, and compared it with the three human lice. Results: We identified all of the 37 mt genes typical of bilateral animals in the chimpanzee louse; these genes are on 18 types of minichromosomes. Seventeen of the 18 minichromosomes of the chimpanzee louse have the same gene content and gene arrangement as their counterparts in the human head louse and the human body louse. However, five genes, cob, trnS1, trnN, trnE and trnM, which are on three minichromosomes in the human head louse and the human body louse, are together on one minichromosome in the chimpanzee louse. Conclusions: Using the human pubic louse, Pt. pubis, as an outgroup for comparison, we infer that a single minichromosome has fragmented into three in the lineage leading to the human head louse and the human body louse since this lineage diverged from the chimpanzee louse ~6 million years ago. Our results provide insights into the process of mt genome fragmentation in the sucking lice in a relatively fine evolutionary scale. [ABSTRACT FROM AUTHOR]

Background: Blood-sucking lice in the genera Pediculus and Pthirus are obligate ectoparasites of great apes. Unlike most bilateral animals, which have 37 mitochondrial (mt) genes on a single circular chromosome, the sucking lice of humans have extensively fragmented mt genomes. The head louse, Pediculus capitis, and the body louse, Pe. humanus, have their 37 mt genes on 20 minichromosomes. The pubic louse, Pthirus pubis, has its 34 mt genes known on 14 minichromosomes. To understand the process of mt genome fragmentation in the sucking lice of great apes, we sequenced the mt genome of the chimpanzee louse, Pe. schaeffi, and compared it with the three human lice. Results: We identified all of the 37 mt genes typical of bilateral animals in the chimpanzee louse; these genes are on 18 types of minichromosomes. Seventeen of the 18 minichromosomes of the chimpanzee louse have the same gene content and gene arrangement as their counterparts in the human head louse and the human body louse. However, five genes, cob, trnS1, trnN, trnE and trnM, which are on three minichromosomes in the human head louse and the human body louse, are together on one minichromosome in the chimpanzee louse. Conclusions: Using the human pubic louse, Pt. pubis, as an outgroup for comparison, we infer that a single minichromosome has fragmented into three in the lineage leading to the human head louse and the human body louse since this lineage diverged from the chimpanzee louse ~6 million years ago. Our results provide insights into the process of mt genome fragmentation in the sucking lice in a relatively fine evolutionary scale. [ABSTRACT FROM AUTHOR]

Background: The genus Haematopinus contains 21 species of blood-sucking lice, parasitizing both even-toed ungulates (pigs, cattle, buffalo, antelopes, camels and deer) and odd-toed ungulates (horses, donkeys and zebras). The mitochondrial genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, Haematopinus apri, have been sequenced recently; both lice have fragmented mitochondrial genomes with 37 genes on nine minichromosomes. To understand whether the composition of mitochondrial minichromosomes and the gene content and gene arrangement of each minichromosome are stable within the genus, we sequenced the mitochondrial genome of the horse louse, Haematopinus asini. Methods: We used a PCR-based strategy to amplify four mitochondrial minichromosomes in near full-length, and then amplify the entire coding regions of all of the nine mitochondrial minichromosomes of the horse louse. These amplicons were sequenced with an Illumina Hiseq platform. Results: We identified all of the 37 mitochondrial genes typical of bilateral animals in the horse louse, Haematopinus asini; these genes are on nine circular minichromosomes. Each minichromosome is 3.5–5.0 kb in size and consists of a coding region and a non-coding region except R-nad4L-rrnS-C minichromosome, which contains two coding regions and two non-coding regions. Six of the nine minichromosomes of the horse louse have their counterparts in the pig lice with the same gene content and gene arrangement. However, the gene content and arrangement of the other three minichromosomes of the horse louse, including R-nad4L-rrnS-C, are different from that of the other three minichromosomes of the pig lice. Conclusions: Comparison between the horse louse and the pig lice revealed variation in the composition of mitochondrial minichromosomes within the genus Haematopinus, which can be accounted for by gene translocation events between minichromosomes. The current study indicates that inter-minichromosome recombination plays a major role in generating the variation in the composition of mitochondrial minichromosomes and provides novel insights into the evolution of fragmented mitochondrial genomes in the blood-sucking lice. [ABSTRACT FROM AUTHOR]

Booklice in the genus Liposcelis are pests of stored grain products. They pose a considerable economic threat to global food security and safety. To date, the complete mitochondrial genome has only been determined for a single booklouse species Liposcelis bostrychophila. Unlike most bilateral animals, which have their 37 mt genes on one circular chromosome, ≈15 kb in size, the mt genome of L. bostrychophila has two circular chromosomes, 8 and 8.5 kb in size. Here, we report the mt genome of another booklouse, Liposcelis decolor. The mt genome of L. decolor has the typical mt chromosome of bilateral animals, 14,405 bp long with 37 genes (13 PCGs, 22 tRNAs and 2 rRNAs). However, the arrangement of these genes in L. decolor differs substantially from that observed in L. bostrychophila and other insects. With the exception of atp8-atp6, L. decolor differs from L. bostrychophila in the arrangement of all of the other 35 genes. The variation in the mt genome organization and mt gene arrangement between the two Liposcelis species is unprecedented for closely related animals in the same genus. Furthermore, our results indicate that the two-chromosome mt genome organization observed in L. bostrychophila likely evolved recently after L. bostrychophila and L. decolor split from their most recent common ancestor. [ABSTRACT FROM AUTHOR]

Background: Human pediculosis is caused by hematophagous lice, which are transmitted between individuals via direct and/or indirect contact. Despite the public health importance of louse infestation, information concerning the global burden of pediculosis and the epidemiological landscape of louse-borne diseases is limited. The aim of this review was to summarize the biology, epidemiology, diagnosis, and control of lice infestation in humans. We also discussed the latest advances in molecular taxonomy and molecular genetics of lice. Methods: We searched five electronic bibliographic databases (PubMed, ScienceDirect, CNKI, VIP Chinese Journal Database, and Wanfang Data) and followed a standard approach for conducting scoping reviews to identify studies on various aspects of human lice. Relevant information reported in the identified studies were collated, categorized, and summarized. Results: A total of 282 studies were eligible for the final review. Human pediculosis remains a public health issue affecting millions of people worldwide. Emerging evidence suggests that head lice and body lice should be considered conspecific, with different genotypes and ecotypes. Phylogenetic analysis based on mitochondrial (mt) cytb gene sequences identified six distinct clades of lice worldwide. In addition to the direct effect on human health, lice can serve as vectors of disease-causing pathogens. The use of insecticides plays a crucial role in the treatment and prevention of louse infestation. Genome sequencing has advanced our knowledge of the genetic structure and evolutionary biology of human lice. Conclusions: Human pediculosis is a public health problem affecting millions of people worldwide, particularly in developing countries. More progress can be made if emphasis is placed on the use of emerging omics technologies to elucidate the mechanisms that underpin the physiological, ecological, and evolutionary aspects of lice. [ABSTRACT FROM AUTHOR]

Blood-sucking lice of humans have extensively fragmented mitochondrial (mt) genomes. Human head louse and body louse have their 37 mt genes on 20 minichromosomes. In human pubic louse, the 34 mt genes known are on 14 minichromosomes. To understand the process of mt genome fragmentation in the blood-sucking lice of mammals, we sequenced the mt genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, H. apri, which diverged from human lice approximately 65 Ma. The 37 mt genes of the pig lice are on nine circular minichromosomes; each minichromosome is 3–4 kb in size. The pig lice have four genes per minichromosome on average, in contrast to two genes per minichromosome in the human lice. One minichromosome of the pig lice has eight genes and is the most gene-rich minichromosome found in the sucking lice. Our results indicate substantial variation in the rate and extent of mt genome fragmentation among different lineages of the sucking lice. [ABSTRACT FROM PUBLISHER]

Background: To investigate the genotype distribution of human papillomavirus (HPV) in infected Uygur and Han women in Xinjiang, China; analyze the HPV16 E6 gene polymorphism site and relationship with the development of cervical cancer. Methods: The HPV16 E6 sequence was analyzed using the European standard prototype to perform an evolutionary tree. HPV16 E6-T295/T350, G295/G350, and T295/G350 GV230 vectors were stably transfected into cervical cancer C33A cells to analyze the cell proliferation, migration and invasion, apoptosis by CCK8 and clonogenic assays, transwell and cell scratch assays, FACS experiments. Results: The total HPV infection rate was 26.390% (760/2879), whereas the Uygur 22.87% (196/857) and the Han was 27.89% (564/2022) (P < 0.05). Among 110 mutations, 65 cases of E6 genes were mutated at nucleotide 350 (T350G) with the leucine changing to valine (L83V). Moreover, there were 7 cases of E6 gene mutated at nucleotide 295 (T295G) with aspartic changing to glutamic (D64E). When E6 vector(s) of mutations sites were transfected into C33A cells, they were found to promote cellular proliferation, migration, invasion, and inhibit apoptosis. T295/G350-E6 was significantly stronger than G295/G350 and T295/T350, G295/G350 was significantly stronger than T295/T350 (P < 0.05). The T295/G350 had the strongest effect on C33A cells and G295/G350 was significantly stronger than T295/T350 (P < 0.05). Conclusions: The positive HPV infection rates differed between the Uygur and Han in Xinjiang, China, and the genotype distribution of infection was different. After transfecting C33A cells with different eukaryotic expression vectors, the T295/G350 mutation site promoted the proliferation, migration, and invasion of C33A cells to a greater extent than G295/G350; however, G295/G350 had a stronger effect than T295/T350. [ABSTRACT FROM AUTHOR]

Background: A single circular mitochondrial (mt) genome is a common feature across most metazoans. The mt-genome includes protein-coding genes involved in oxidative phosphorylation, as well as RNAs necessary for translation of mt-RNAs, whose order and number are highly conserved across animal clades, with few known exceptions of alternative mt-gene order or mt-genome architectures. One such exception consists of the fragmented mitochondrial genome, a type of genome architecture where mt-genes are split across two or more mt-chromosomes. However, the origins of mt-genome fragmentation and its effects on mt-genome evolution are unknown. Here, we investigate these origin and potential mechanisms underlying mt-genome fragmentation, focusing on a genus of booklice, Liposcelis, which exhibits elevated sequence divergence, frequent rearrangement of mt-gene order, and fragmentation of the mt genome, and compare them to other Metazoan clades. Results: We found this genus Liposcelis exhibits very low conservation of mt-gene order across species, relative to other metazoans. Levels of gene order rearrangement were, however, unrelated to whether or not mt-genomes were fragmented or intact, suggesting mitochondrial genome fragmentation is not affecting mt-gene order directly. We further investigated possible mechanisms underpinning these patterns and revealed very high conservation of non-coding sequences at the edges of multiple recombination regions across populations of one particular Liposcelis species, supportive of a hypothesis that mt-fragmentation arises from recombination errors between mt-genome copies. We propose these errors may arise as a consequence of a heightened mutation rate in clades exhibiting mt-fragmentation. Consistent with this, we observed a striking pattern across three Metazoan phyla (Arthropoda, Nematoda, Cnidaria) characterised by members exhibiting high levels of mt-gene order rearrangement and cases of mt-fragmentation, whereby the mt-genomes of species more closely related to species with fragmented mt-genomes diverge more rapidly despite experiencing strong purifying selection. Conclusions: We showed that contrary to expectations, mt-genome fragmentation is not correlated with the increase in mt-genome rearrangements. Furthermore, we present evidence that fragmentation of the mt-genome may be part of a general relaxation of a natural selection on the mt-genome, thus providing new insights into the origins of mt-genome fragmentation and evolution. [ABSTRACT FROM AUTHOR]

Background: Xinjiang is one of the regions with a high incidence of cervical cancer, and the genetic variation of human papillomavirus may increase its ability to infect the human body and enhance virus-mediated immune escape ability. Methods: Sanger sequencing of the HPV16 genome from 165 samples positive for HPV16 infection and phylogenetic analysis of the E1 and E2 genes revealed the gene polymorphism of HPV16 in Xinjiang. Results: The results showed that there were 109 samples with variations in HPV16 E1, 48 sites with nucleotide variations (19 missense variations and 29 synonymous variations), and 91 samples with variations in HPV16 E2, 25 sites with nucleotide variations (20 missense variations and five synonymous variations). Conclusions: From the phylogenetic tree results, 149 samples were of the European variant and 16 samples were of the Asian variant. No African or North American/Asian variant types were found. [ABSTRACT FROM AUTHOR]

Background: The typical single-chromosome mitochondrial (mt) genome of animals has fragmented into multiple minichromosomes in the lineage Mitodivisia, which contains most of the parasitic lice of eutherian mammals. These parasitic lice differ from each other even among congeneric species in mt karyotype, i.e. the number of minichromosomes, and the gene content and gene order in each minichromosome, which is in stark contrast to the extremely conserved single-chromosome mt genomes across most animal lineages. How fragmented mt genomes evolved is still poorly understood. We use Polyplax sucking lice as a model to investigate how tRNA gene translocation shapes the dynamic mt karyotypes. Results: We sequenced the full mt genome of the Asian grey shrew louse, Polyplax reclinata. We then inferred the ancestral mt karyotype for Polyplax lice and compared it with the mt karyotypes of the three Polyplax species sequenced to date. We found that tRNA genes were entirely responsible for mt karyotype variation among these three species of Polyplax lice. Furthermore, tRNA gene translocation observed in Polyplax lice was only between different types of minichromosomes and towards the boundaries with the control region. A similar pattern of tRNA gene translocation can also been seen in other sucking lice with fragmented mt genomes. Conclusions: We conclude that inter-minichromosomal tRNA gene translocation orientated towards the boundaries with the control region is a major contributing factor to the highly dynamic mitochondrial genome organization in the parasitic lice of mammals. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to determine whether ZNF582 gene methylation and tissue protein expression can be used as a tool with high sensitivity and specificity for cervical cancer screening. We analyzed the correlation between promoter methylation of ZNF582 gene and cervical cancer and high risk HPV16/18 infection. Methods: Tissue samples of normal cervical or chronic cervicitis (n=51), CIN (cervical intraepithelial neoplasia) (n=35), and cervical carcinoma (n=68) were tested for HPV16/18 infection by polymerase chain reaction (PCR). We also detected the methylation status of the ZNF582 gene promoter in the same tissues by methylation-specific PCR (MSP), then analyzed the correlation between ZNF582 promoter methylation and HPV16/18 infection. Immunohistochemistry was used to analyze ZNF582 gene expression in 152 cervical tissues. We detected ZNF582 mRNA expression in cervical tissues (including cancer and non-cancer) by real-time fluorescence quantitative PCR (qPCR). Results: Among 93 high-grade cervical lesions (CINII and above) and cervical cancer samples, 57 cases were positive for HPV16/18 infection and 36 cases were negative. ZNF582 gene methylation occurred in 9 out of 51 cases in normal cervical tissues (17.6%), 16 of 35 cases in CIN tissues (45.7%), and 50 of 68 cases in cervical cancer (73.5%). The differences in methylation rate of the three groups were statistically significant (P< 0.05). The ZNF582 methylation rate in the positive HPV16/18 infection group was 73.7%, while the negative group was 63.9%. Compared with normal tissues, ZNF582 protein was highly expressed in cervical cancer tissues, but mRNA expression was low. Conclusion: While ZNF582 protein is highly expressed in cervical cancer tissues, it was not sufficient for use as a standard for cervical cancer staging. On the other hand, ZNF582 promoter methylation had high specificity and sensitivity in detecting CINII and highly diseased cervical lesions and could be used as a diagnostic marker for cervical cancer of women. [ABSTRACT FROM AUTHOR]

We report for the first time the fragmented mitochondrial (mt) genomes of two Pedicinus species: Pedicinus obtusus and Pedicinus badii , and compared them with the lice of humans and chimpanzees. Despite being congeneric, the two monkey lice are distinct from each other in mt karyotype. The variation in mt karyotype between the two Pedicinus lice is the most pronounced among the congeneric species of sucking lice observed to date and is attributable to the opposite directions between them in mt karyotype evolution. Two of the inferred ancestral mt minichromosomes of the higher primate lice merged as one in the macaque louse whereas one of the ancestral minichromosomes split into two in the colobus louse after these two species diverged from their most recent common ancestor. Our results showed that mt genome fragmentation was a two-way process in the higher primate lice, and minichromosome merger was more common than previously thought. • We report the fragmented mitochondrial genomes of two Pedicinus species: Pedicinus obtusus and Pedicinus badii. • The two monkey lice are distinct from each other in mitochondrial karyotype. • Our results showed that mitochondrial genome fragmentation was a two-way process in the higher primate lice. [ABSTRACT FROM AUTHOR]

Organelle genome fragmentation has been found in a wide range of eukaryotic lineages; however, its use in phylogenetic reconstruction has not been demonstrated. We explored the use of mitochondrial (mt) genome fragmentation in resolving the controversial suborder-level phylogeny of parasitic lice (order Phthiraptera). There are approximately 5000 species of parasitic lice in four suborders (Amblycera, Ischnocera, Rhynchophthirina, and Anoplura), which infest mammals and birds. The phylogenetic relationships among these suborders are unresolved despite decades of studies. We sequenced the mt genomes of eight species of parasitic lice and compared them with 17 other species of parasitic lice sequenced previously. We found that the typical single-chromosome mt genome is retained in the lice of birds but fragmented into many minichromosomes in the lice of eutherian mammals. The shared derived feature of mt genome fragmentation unites the eutherian mammal lice of Ischnocera (family Trichodectidae) with Anoplura and Rhynchophthirina to the exclusion of the bird lice of Ischnocera (family Philopteridae). The novel clade, namely Mitodivisia, is also supported by phylogenetic analysis of mt genome and cox1 gene sequences. Our results demonstrate, for the first time, that organelle genome fragmentation is informative for resolving controversial high-level phylogenies. [ABSTRACT FROM AUTHOR]

Background: Mitochondrial (mt) genomes of animals typically contain 37 genes for 13 proteins, two ribosomal RNA (rRNA) genes and 22 transfer RNA (tRNA) genes. In sarcoptiform mites, the entire set of mt tRNA genes is present in Aleuroglyphus ovatus, Caloglyphus berlesei, Dermatophagoides farinae, D. pteronyssinus, Histiostoma blomquisti and Psoroptes cuniculi. Loss of 16 mt tRNA genes, however, was reported in Steganacarus magnus; loss of 2–3 tRNA genes was reported in Tyrophagus longior, T. putrescentiae and Sarcoptes scabiei. Nevertheless, convincing evidence for mt gene loss is lacking in these mites. Results: We sequenced the mitochondrial genomes of two sarcoptiform mites, Histiostoma feroniarum (13,896 bp) and Rhizoglyphus robini (14,244 bp). Using tRNAScan and ARWEN programs, we identified 16 and 17 tRNA genes in the mt genomes of H. feroniarum and R. robini, respectively. The other six mt tRNA genes in H. feroniarum and five mt tRNA genes in R. robini can only be identified manually by sequence comparison when alternative anticodons are considered. We applied this manual approach to other mites that were reported previously to have lost mt tRNA genes. We were able to identify all of the 16 mt tRNA genes that were reported as lost in St. magnus, two of the three mt tRNA genes that were reported as lost in T. longior and T. putrescentiae, and the two mt tRNA genes that were reported as lost in Sa. scabiei. All of the tRNA genes inferred from these manually identified genes have truncation in the arms and mismatches in the stems. Conclusions: Our results reveal very unconventional tRNA structures in sarcoptiform mites and do not support the loss of mt tRNA genes in these mites. The functional implication of the drastic structural changes in these tRNA genes remains to be investigated. [ABSTRACT FROM AUTHOR]

Eriophyoid mites (superfamily Eriophyoidea) comprise >4400 species worldwide. Despite over a century of study, the phylogenetic position of these mites within Acariformes is still poorly resolved. Currently, Eriophyoidea is placed in the order Trombidiformes. We inferred the high-level phylogeny of Acari with the mitochondrial (mt) genome sequences of 110 species including four eriophyoid species, and the nuclear small subunit ( 18S ) rRNA gene sequences of 226 species including 25 eriophyoid species. Maximum likelihood (ML), Bayesian inference (BI) and Maximum parsimony (MP) methods were used to analyze the sequence data. Divergence times were estimated for major lineages of Acari using Bayesian approaches. Our analyses consistently recovered the monophyly of Eriophyoidea but rejected the monophyly of Trombidiformes. The eriophyoid mites were grouped with the sarcoptiform mites, or were the sister group of sarcoptiform mites + non-eriophyoid trombidiform mites, depending on data partition strategies. Eriophyoid mites diverged from other mites in the Devonian (384 Mya, 95% HPD, 352–410 Mya). The origin of eriophyoid mites was dated to the Permian (262 Mya, 95% HPD 230–307 Mya), mostly prior to the radiation of gymnosperms (Triassic-Jurassic) and angiosperms (early Cretaceous). We propose that the placement of Eriophyoidea in the order Trombidiformes under the current classification system should be reviewed. [ABSTRACT FROM AUTHOR]

The Coleoptera (beetles) exhibits tremendous morphological, ecological, and behavioral diversity. To better understand the phylogenetics and evolution of beetles, we sequenced three complete mitogenomes from two families (Cleridae and Meloidae), which share conserved mitogenomic features with other completely sequenced beetles. We assessed the influence of six datasets and three inference methods on topology and nodal support within the Coleoptera. We found that both Bayesian inference and maximum likelihood with homogeneous-site models were greatly affected by nucleotide compositional heterogeneity, while the heterogeneous-site mixture model in PhyloBayes could provide better phylogenetic signals for the Coleoptera. The amino acid dataset generated more reliable tree topology at the higher taxonomic levels (i.e. suborders and series), where the inclusion of rRNA genes and the third positions of protein-coding genes improved phylogenetic inference at the superfamily level, especially under a heterogeneous-site model. We recovered the suborder relationships as (Archostemata + Adephaga) + (Myxophaga + Polyphaga). The series relationships within Polyphaga were recovered as (Scirtiformia + (Elateriformia + ((Bostrichiformia + Scarabaeiformia + Staphyliniformia) + Cucujiformia))). All superfamilies within Cucujiformia were recovered as monophyletic. We obtained a cucujiform phylogeny of (Cleroidea + (Coccinelloidea + ((Lymexyloidea + Tenebrionoidea) + (Cucujoidea + (Chrysomeloidea + Curculionoidea))))). This study showed that although tree topologies were sensitive to data types and inference methods, mitogenomic data could provide useful information for resolving the Coleoptera phylogeny at various taxonomic levels by using suitable datasets and heterogeneous-site models. [ABSTRACT FROM AUTHOR]

Mitochondrial functions are crucial for pancreatic β-cell survival and glucose-induced insulin secretion. Hexarelin (Hex) is a synthetic small peptide ghrelin analogue, which has been shown to protect cardiomyocytes from the ischemia-reperfusion process. In this study, we used in vitro and in vivo models of streptozotocin (STZ)-induced β-cell damage to study the protective effect of Hex and the associated mechanisms. We found that STZ produced a cytotoxic effect in a dose- and time-dependent manner in MIN6 cells (a mouse β-cell line). Hex (1.0 μM) decreased the STZ-induced damage in β-cells. Rhodamine 123 assay and superoxide DHE production assay revealed that Hex ameliorated STZ-induced mitochondrial damage and excessive superoxide activity in β-cells. In addition, Hex significantly reduced STZ-induced expression of cleaved Caspases-3, Caspases-9 and the ratio of pro-apoptotic protein Bax to anti-apoptotic protein Bcl-2 in MIN6 cells. We further examined the in vivo effect of Hex in a rat model of type 1 diabetes induced by STZ injection. Hex ameliorated STZ-induced decrease in plasma insulin and protected the structure of islets from STZ-induced disruption. Hex also ameliorated STZ-induced expression of cleaved Caspase-9 and the Bax in β-cells. In conclusion, our data indicate that Hex is able to protects β-cell mass from STZ-caused cytotoxic effects involving mitochondrial pathways in vitro and in vivo. Hex may serve as a potential protective agent for the management of diabetes. [ABSTRACT FROM AUTHOR]