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1.  Multiple lineages of lice pass through the K–Pg boundary 
Biology Letters  2011;7(5):782-785.
For modern lineages of birds and mammals, few fossils have been found that predate the Cretaceous–Palaeogene (K–Pg) boundary. However, molecular studies using fossil calibrations have shown that many of these lineages existed at that time. Both birds and mammals are parasitized by obligate ectoparasitic lice (Insecta: Phthiraptera), which have shared a long coevolutionary history with their hosts. Evaluating whether many lineages of lice passed through the K–Pg boundary would provide insight into the radiation of their hosts. Using molecular dating techniques, we demonstrate that the major louse suborders began to radiate before the K–Pg boundary. These data lend support to a Cretaceous diversification of many modern bird and mammal lineages.
PMCID: PMC3169043  PMID: 21471047
Phthiraptera; evolution; cospeciation; dating
2.  A review of the genus Neopsocopsis (Psocodea, “Psocoptera”, Psocidae), with one new species from China  
ZooKeys  2012;27-46.
A review of species of the genus Neopsocopsis Badonnel, 1936 is presented. Four species are redescribed, viz. Neopsocopsis hirticornis (Reuter, 1893), Neopsocopsis quinquedentata (Li & Yang, 1988), Neopsocopsis profunda (Li, 1995), and Neopsocopsis flavida (Li, 1989), as well as the description of one new species, Neopsocopsis convexa sp. n. Seven new synonymies are proposed as follows: Pentablaste obconica Li syn. n. and Pentablaste clavata Li syn. n. of Neopsocopsis hirticornis, Pentablaste tetraedrica Li syn. n. of Neopsocopsis longiptera, Neoblaste schizopetala Li syn. n. and Neoblaste flavae Li syn. n. of Neopsocopsis profunda, Blastopsocidus pini Li syn. n. and Pentablaste lanceolata Li syn. n. of Neopsocopsis flavida. Neopsocopsis hirticornis (Reuter, 1893) is recorded from Japan and China for the first time, and Neopsocopsis longiptera Vishnyakova, 1986 is newly recorded from China. Illustrated keys to adult males and females are presented.
PMCID: PMC3381698  PMID: 22773912
Psocodea; Psocoptera; Psocidae; Neopsocopsis; redescriptions; new synonymies; new species; new records; distribution; key
3.  Phylogeographic Analysis Elucidates the Influence of the Ice Ages on the Disjunct Distribution of Relict Dragonflies in Asia 
PLoS ONE  2012;7(5):e38132.
Unusual biogeographic patterns of closely related groups reflect events in the past, and molecular analyses can help to elucidate these events. While ample research on the origin of disjunct distributions of different organism groups in the Western Paleartic has been conducted, such studies are rare for Eastern Palearctic organisms. In this paper we present a phylogeographic analysis of the disjunct distribution pattern of the extant species of the strongly cool-adapted Epiophlebia dragonflies from Asia. We investigated sequences of the usually more conserved 18 S rDNA and 28 S rDNA genes and the more variable sequences of ITS1, ITS2 and CO2 of all three currently recognised Epiophlebia species and of a sample of other odonatan species. In all genes investigated the degrees of similarity between species of Epiophlebia are very high and resemble those otherwise found between different populations of the same species in Odonata. This indicates that substantial gene transfer between these populations occurred in the comparatively recent past. Our analyses imply a wide distribution of the ancestor of extant Epiophlebia in Southeast Asia during the last ice age, when suitable habitats were more common. During the following warming phase, its range contracted, resulting in the current disjunct distribution. Given the strong sensitivity of these species to climatic parameters, the current trend to increasing global temperatures will further reduce acceptable habitats and seriously threaten the existences of these last representatives of an ancient group of Odonata.
PMCID: PMC3364219  PMID: 22666462
4.  Mitochondrial genome deletions and minicircles are common in lice (Insecta: Phthiraptera) 
BMC Genomics  2011;12:394.
The gene composition, gene order and structure of the mitochondrial genome are remarkably stable across bilaterian animals. Lice (Insecta: Phthiraptera) are a major exception to this genomic stability in that the canonical single chromosome with 37 genes found in almost all other bilaterians has been lost in multiple lineages in favour of multiple, minicircular chromosomes with less than 37 genes on each chromosome.
Minicircular mt genomes are found in six of the ten louse species examined to date and three types of minicircles were identified: heteroplasmic minicircles which coexist with full sized mt genomes (type 1); multigene chromosomes with short, simple control regions, we infer that the genome consists of several such chromosomes (type 2); and multiple, single to three gene chromosomes with large, complex control regions (type 3). Mapping minicircle types onto a phylogenetic tree of lice fails to show a pattern of their occurrence consistent with an evolutionary series of minicircle types. Analysis of the nuclear-encoded, mitochondrially-targetted genes inferred from the body louse, Pediculus, suggests that the loss of mitochondrial single-stranded binding protein (mtSSB) may be responsible for the presence of minicircles in at least species with the most derived type 3 minicircles (Pediculus, Damalinia).
Minicircular mt genomes are common in lice and appear to have arisen multiple times within the group. Life history adaptive explanations which attribute minicircular mt genomes in lice to the adoption of blood-feeding in the Anoplura are not supported by this expanded data set as minicircles are found in multiple non-blood feeding louse groups but are not found in the blood-feeding genus Heterodoxus. In contrast, a mechanist explanation based on the loss of mtSSB suggests that minicircles may be selectively favoured due to the incapacity of the mt replisome to synthesize long replicative products without mtSSB and thus the loss of this gene lead to the formation of minicircles in lice.
PMCID: PMC3199782  PMID: 21813020
5.  Bacterial Endosymbiont of the Slender Pigeon Louse, Columbicola columbae, Allied to Endosymbionts of Grain Weevils and Tsetse Flies▿  
Applied and Environmental Microbiology  2007;73(20):6660-6668.
The current study focuses on a symbiotic bacterium found in the slender pigeon louse, Columbicola columbae (Insecta: Phthiraptera). Molecular phylogenetic analyses indicated that the symbiont belongs to the gamma subdivision of the class Proteobacteria and is allied to Sodalis glossinidius, the secondary symbiont of tsetse flies (Glossina spp.) and also to the primary symbiont of grain weevils (Sitophilus spp.). Relative-rate tests revealed that the symbiont of C. columbae exhibits accelerated molecular evolution in comparison with the tsetse fly symbiont and the weevil symbiont. Whole-mount in situ hybridization was used to localize the symbiont and determine infection dynamics during host development. In first- and second-instar nymphs, the symbionts were localized in the cytoplasm of oval bacteriocytes that formed small aggregates on both sides of the body cavity. In third-instar nymphs, the bacteriocytes migrated to the central body and were finally located in the anterior region of the lateral oviducts, forming conspicuous tissue formations called ovarial ampullae. In adult females, the symbionts were transmitted from the ovarial ampullae to developing oocytes in the ovarioles. In adult males, the bacteriocytes often disappeared without migration. A diagnostic PCR survey of insects collected from Japan, the United States, Australia, and Argentina detected 96.5% (109/113) infection, with a few uninfected male insects. This study provides the first microbial characterization of a bacteriocyte-associated symbiont from a chewing louse. Possible biological roles of the symbiont are discussed in relation to the host nutritional physiology associated with the feather-feeding lifestyle.
PMCID: PMC2075037  PMID: 17766458
6.  Symbiotic Bacteria Associated with Stomach Discs of Human Lice▿ †  
Applied and Environmental Microbiology  2006;72(11):7349-7352.
The symbiotic bacteria associated with the stomach disc, a large aggregate of bacteriocytes on the ventral side of the midgut, of human body and head lice were characterized. Molecular phylogenetic analysis of 16S rRNA gene sequences showed that the symbionts formed a distinct and well-defined clade in the Gammaproteobacteria. The sequences exhibited AT-biased nucleotide composition and accelerated molecular evolution. In situ hybridization revealed that in nymphs and adult males, the symbiont was localized in the stomach disc, while in adult females, the symbiont was not in the stomach disc but in the lateral oviducts and the posterior pole of the oocytes due to female-specific symbiont migration. We propose the designation “Candidatus Riesia pediculicola” for the louse symbionts.
PMCID: PMC1636134  PMID: 16950915
7.  Multiple origins of parasitism in lice. 
A major fraction of the diversity of insects is parasitic, as herbivores, parasitoids or vertebrate ectopara sites. Understanding this diversity requires information on the origin of parasitism in various insect groups. Parasitic lice (Phthiraptera) are the only major group of insects in which all members are permanent parasites of birds or mammals. Lice are classified into a single order but are thought to be closely related to, or derived from, book lice and bark lice (Psocoptera). Here, we use sequences of the nuclear 18S rDNA gene to investigate the relationships among Phthiraptera and Psocoptera and to identify the origins of parasitism in this group (termed Psocodea). Maximum-likelihood (ML), Bayesian ML and parsimony analyses of these data indicate that lice are embedded within the psocopteran infraorder Nanopsocetae, making the order Psocoptera paraphyletic (i.e. does not contain all descendants of a single common ancestor). Furthermore, one family of Psocoptera, Liposcelididae, is identified as the sister taxon to the louse suborder Amblycera, making parasitic lice (Phthiraptera) a polyphyletic order (i.e. descended from two separate ancestors). We infer from these results that parasitism of vertebrates arose twice independently within Psocodea, once in the common ancestor of Amblycera and once in the common ancestor of all other parasitic lice.
PMCID: PMC1691793  PMID: 15315891

Results 1-7 (7)