In host-symbiont systems, interspecific transmissions create opportunities for host switches, potentially leading to cophylogenetic incongruence. In contrast, conspecific transmissions often result in high host specificity and congruent cophylogenies. In most bird-feather mite systems, conspecific transmission is considered dominant, while interspecific transmission is supposedly rare.
View Article and Find Full Text PDFMost humans carry mites in the hair follicles of their skin for their entire lives. Follicular mites are the only metazoans tha continuously live on humans. We propose that Demodex folliculorum (Acari) represents a transitional stage from a host-injuring obligate parasite to an obligate symbiont.
View Article and Find Full Text PDFOver the past few decades, there has been a growing demand for genome analysis of ancient human remains. Destructive sampling is increasingly difficult to obtain for ethical reasons, and standard methods of breaking the skull to access the petrous bone or sampling remaining teeth are often forbidden for curatorial reasons. However, most ancient humans carried head lice and their eggs abound in historical hair specimens.
View Article and Find Full Text PDFMetamorphosis is a key innovation allowing the same species to inhabit different environments and accomplish different functions, leading to evolutionary success in many animal groups. Astigmata is a megadiverse lineage of mites that expanded into a great number of habitats via associations with invertebrate and vertebrate hosts (human associates include stored food mites, house dust mites, and scabies). The evolutionary success of Astigmata is linked to phoresy-related metamorphosis, namely the origin of the heteromorphic deutonymph, which is highly specialized for phoresy (dispersal on hosts).
View Article and Find Full Text PDFThe biology of macrochelid mites might offer new venues for the interpretation of the environmental conditions surrounding human death and decomposition. Three human corpses, one from Sweden and two from Spain, have been analysed for the occurrence of Macrochelidae species. Macrocheles muscaedomesticae (Scopoli) females were associated with a corpse that was found in a popular beach area of southeast Spain.
View Article and Find Full Text PDFGenetic and sexual systems can be evolutionarily dynamic within and among clades. However, identifying the processes responsible for switches between, for instance, sexual and asexual reproduction, or cyclic and non-cyclic life histories remains challenging. When animals evolve parthenogenetic reproduction, information about the sexual mating system becomes lost.
View Article and Find Full Text PDFProctolaelaps euserratus Karg, 1994 (Acari, Mesostigmata, Melicharidae), exclusivelly known from the Galápagos Islands till now, is newly reported from decaying matter of animal and human decomposition in various countries of Europe (Slovakia, Spain, United Kingdom). In consequence of high levels of necrophilia, the species is considered to be ecologically unusual among the other melicharids, which are primary associated with other than necrophilic habitats, such as galleries of subcorticolous beetles, bumble bee nests, flowers, etc. Proctolaelaps euserratus is reviewed, morphologically re-described (with first diagnostic characters for males), and considered as a new potential marker for later stages of decomposition, namely butyric fermentation and dry decomposition as classified in modern concepts of forensic acarology.
View Article and Find Full Text PDFAnkyrin repeat domain-encoding genes are common in the eukaryotic and viral domains of life, but they are rare in bacteria, the exception being a few obligate or facultative intracellular Proteobacteria species. Despite having a reduced genome, the arthropod strains of the alphaproteobacterium Wolbachia contain an unusually high number of ankyrin repeat domain-encoding genes ranging from 23 in wMel to 60 in wPip strain. This group of genes has attracted considerable attention for their astonishing large number as well as for the fact that ankyrin proteins are known to participate in protein-protein interactions, suggesting that they play a critical role in the molecular mechanism that determines host-Wolbachia symbiotic interactions.
View Article and Find Full Text PDFWe designed fluorescence in situ hybridization probes for two distinct microsporidian clades and demonstrated their application in detecting, respectively, Nosema/Vairimorpha and Dictyoceola species. We used them to study the vertical transmission of two microsporidia infecting the amphipod Gammarus duebeni.
View Article and Find Full Text PDFParasitic mites associated with spiders are spreading world-wide through the trade in tarantulas and other pet species. Ljunghia pulleinei Womersley, a mesostigmatic laelapid mite originally found in association with the mygalomorph spider Selenocosmia stirlingi Hogg (Theraphosidae) in Australia, is redescribed and illustrated on the basis of specimens from the African theraphosid spider Pterinochilus chordatus (Gerstäcker) kept in captivity in the British Isles (Wales). The mite is known from older original descriptions of Womersley in 1956; the subsequent redescription of Domrow in 1975 seems to be questionable in conspecificity of treated specimens with the type material.
View Article and Find Full Text PDFBackground: Cutaneous leishmaniasis is a neglected, vector-borne parasitic disease and is responsible for persistent, often disfiguring lesions and other associated complications. Leishmania, causing zoonotic cutaneous leishmaniasis (ZCL) in the Old World are mainly transmitted by the predominant sand fly vector, Phlebotomus papatasi. To date, there is no efficient control measure or vaccine available for this widespread insect-borne infectious disease.
View Article and Find Full Text PDFInternal bacterial communities of synanthropic mites Acarus siro, Dermatophagoides farinae, Lepidoglyphus destructor, and Tyrophagus putrescentiae (Acari: Astigmata) were analyzed by culturing and culture-independent approaches from specimens obtained from laboratory colonies. Homogenates of surface-sterilized mites were used for cultivation on non-selective agar and DNA extraction. Isolated bacteria were identified by sequencing of the 16S rRNA gene.
View Article and Find Full Text PDFWolbachia is an obligatory intracellular bacterium which often manipulates the reproduction of its insect and isopod hosts. In contrast, Wolbachia is an essential symbiont in filarial nematodes. Lately, Wolbachia has been implicated in genomic imprinting of host DNA through cytosine methylation.
View Article and Find Full Text PDFTwo new gregarines in the recently erected genus Psychodiella (formerly Ascogregarina), Psychodiella sergenti n. sp. and Psychodiella tobbi n.
View Article and Find Full Text PDFAs an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb.
View Article and Find Full Text PDFMites are involved in the decomposition of animal carcases and human corpses at every stage. From initial decay at the fresh stage until dry decomposition at the skeletal stage, a huge diversity of Acari, including members of the Mesostigmata, Prostigmata, Astigmata, Endeostigmata, Oribatida and Ixodida, are an integral part of the constantly changing food webs on, in and beneath the carrion. During the desiccation stage in wave 6 of Mégnin's system, mites can become the dominant fauna on the decomposing body.
View Article and Find Full Text PDFMites can be found in all imaginable terrestrial habitats, in freshwater, and in salt water. Mites can be found in our houses and furnishings, on our clothes, and even in the pores of our skin-almost every single person carries mites. Most of the time, we are unaware of them because they are small and easily overlooked, and-most of the time-they do not cause trouble.
View Article and Find Full Text PDFPhoretic mites are likely the most abundant arthropods found on carcases and corpses. They outnumber their scavenger carriers in both number and diversity. Many phoretic mites travel on scavenger insects and are highly specific; they will arrive on a particular species of host and no other.
View Article and Find Full Text PDFThe obligate intracellular bacterium Wolbachia pipientis infects around 20% of all insect species. It is maternally inherited and induces reproductive alterations of insect populations by male killing, feminization, parthenogenesis, or cytoplasmic incompatibility. Here, we present the 1,445,873-bp genome of W.
View Article and Find Full Text PDFBackground: Primary bacterial endosymbionts of insects (p-endosymbionts) are thought to be undergoing the process of Muller's ratchet where they accrue slightly deleterious mutations due to genetic drift in small populations with negligible recombination rates. If this process were to go unchecked over time, theory predicts mutational meltdown and eventual extinction. Although genome degradation is common among p-endosymbionts, we do not observe widespread p-endosymbiont extinction, suggesting that Muller's ratchet may be slowed or even stopped over time.
View Article and Find Full Text PDFWolbachia are obligate intracellular bacteria which commonly infect arthropods. They are maternally inherited and capable of altering host development, sex determination, and reproduction. Reproductive manipulations include feminization, male-killing, parthenogenesis, and cytoplasmic incompatibility.
View Article and Find Full Text PDFThe first mycetome was discovered more than 340 yr ago in the human louse. Despite the remarkable biology and medical and social importance of human lice, its primary endosymbiont has eluded identification and characterization. Here, we report the host-symbiont interaction of the mycetomic bacterium of the head louse Pediculus humanus capitis and the body louse P.
View Article and Find Full Text PDFThe primary endosymbiotic bacteria from three species of parasitic primate lice were characterized molecularly. We have confirmed the characterization of the primary endosymbiont (P-endosymbiont) of the human head/body louse Pediculus humanus and provide new characterizations of the P-endosymbionts from Pediculus schaeffi from chimpanzees and Pthirus pubis, the pubic louse of humans. The endosymbionts show an average percent sequence divergence of 11 to 15% from the most closely related known bacterium "Candidatus Arsenophonus insecticola.
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