@article {96565, title = {Sequencing of a New Target Genome: thePediculus humanus humanus(Phthiraptera: Pediculidae) Genome Project}, journal = {Journal of Medical Entomology}, volume = {43}, year = {2006}, month = {Nov-01-2006}, pages = {1103-1111}, type = {Open Access}, abstract = {

The human body louse, Pediculus humanus humanus (L.), and the human head louse, Pediculus humanus capitis, belong to the hemimetabolous order Phthiraptera. The body louse is the primary vector that transmits the bacterial agents of louse-borne relapsing fever, trench fever, and epidemic typhus. The genomes of the bacterial causative agents of several of these aforementioned diseases have been sequenced. Thus, determining the body louse genome will enhance studies of host-vector-pathogen interactions. Although not important as a major disease vector, head lice are of major social concern. Resistance to traditional pesticides used to control head and body lice have developed. It is imperative that new molecular targets be discovered for the development of novel compounds to control these insects. No complete genome sequence exists for a hemimetabolous insect species primarily because hemimetabolous insects often have large (2,000 Mb) to very large (up to 16,300 Mb) genomes. Fortuitously, we determined that the human body louse has one of the smallest genome sizes known in insects, suggesting it may be a suitable choice as a minimal hemimetabolous genome in which many genes have been eliminated during its adaptation to human parasitism. Because many louse species infest birds and mammals, the body louse genome-sequencing project will facilitate studies of their comparative genomics. A 6-8\× coverage of the body louse genome, plus sequenced expressed sequence tags, should provide the entomological, evolutionary biology, medical, and public health communities with useful genetic information.

}, keywords = {Pediculosis, reduced genomic complexity, resistance}, issn = {0022-2585, 1938-2928}, doi = {10.1093/jmedent/43.6.1103}, url = {https://academic.oup.com/jme/article/43/6/1103/889089}, author = {Barry R. Pittendrigh and Clark,J. Marshall and J. Spencer Johnston and Sang Hong Lee and Romero-Severson,Jeanne and Gregory Alan Dasch} } @article {94764, title = {Detoxification of ivermectin by ATP binding cassette transporter C4 and cytochrome P450 monooxygenase 6CJ1 in the human body louse, Pediculus humanus humanus}, journal = {Insect Molecular Biology}, volume = {27}, year = {2018}, month = {07-2017}, pages = {73 - 82}, abstract = {

We previously observed that ivermectin-induced detoxification genes, including ATP binding cassette transporter C4 (PhABCC4) and cytochrome P450 6CJ1 (CYP6CJ1) were identified from body lice following a brief exposure to a sublethal dose of ivermectin using a non-invasive induction assay. In this current study, the functional properties of PhABCC4 and CYP6CJ1 were investigated after expression in either X. laevis oocytes or using a baculovirus expression system, respectively. Efflux of [3H]-9-(2-phosphonomethoxyethyl) adenine ([3H]-PMEA), a known ABCC4 substrate in humans, was detected from PhABCC4 cRNA-injected oocytes by liquid scintillation spectrophotometric analysis and PhABCC4 expression in oocytes was confirmed using ABC transporter inhibitors. Efflux was also determined to be ATP-dependent. Using a variety of insecticides in a competition assay, only co-injection of ivermectin and dichlorodiphenyltrichloroethane led to decreased efflux of [3H]-PMEA. PhABCC4-expressing oocytes also directly effluxed [3H]-ivermectin, which increased over time. In addition, ivermectin appeared to be oxidatively metabolized and/or sequestered, although at low levels, following functional expression of CYP6CJ1 along with cytochrome P450 reductase in Sf9 cells. Our study suggests that PhABCC4 and perhaps CYP6CJ1 are involved in the Phase III and Phase I xenobiotic metabolism of ivermectin, respectively, and may play an important role in the evolution of ivermectin resistance in lice and other insects as field selection occurs.

}, doi = {10.1111/imb.12348}, url = {http://doi.wiley.com/10.1111/imb.12348}, author = {J. H. Kim and K. J. Gellatly and B. Lueke and M. Kohler and Ralf Nauen and Edwin Murenzi and Kyong Sup Yoon and Clark,J. Marshall} } @inbook {94663, title = {New Developments in the Control of Human Lice}, booktitle = {Ectoparaistes}, year = {2018}, pages = {119 - 137}, publisher = {Wiley-VCH Verlag GmbH \& Co. KGaA}, organization = {Wiley-VCH Verlag GmbH \& Co. KGaA}, chapter = {6}, address = {Weinheim, Germany}, abstract = {

Human head and body lice represent one of the longest and most prevalent parasitic infestations of humans. While head lice are an economic and social concern, body lice pose a more serious public health concern. In the past 10 years, significant progress has been made in the study of human lice and the information generated has led to a number of new developments for their control. The in vitro rearing of head and body lice has allowed the establishment of insecticide-susceptible and -resistant reference strains, which have allowed more formal descriptions of pediculicide resistance, its underlying mechanisms, and the detection and monitoring of resistance. Likewise, the availability of inbred strains has allowed the efficient sequencing, assembly, and annotation of the genomes and transcriptomes of both lice. This information enabled the use of functional genomics and reverse genetics to study the genes involved in the evolution of resistance, the odorant response to attractants and repellents, and the discovery of novel target sites for the development of new pediculicidal/ovicidal chemicals and metabolic synergists. With these tools and techniques, we are now poised for the first time to make substantial advancements in providing society with effective treatments for pediculosis in a sustainable resistance management format.

}, keywords = {body lice, control strategies, genomes, head lice, human lice, in vitro rearing system, knockdown resistance, pediculicide resistance, Pediculosis, Pyrethroid, transcriptomes}, isbn = {9783527341689}, doi = {10.1002/9783527802883.ch6}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/9783527802883.ch6}, author = {Clark,J. Marshall}, editor = {Meng, Charles Q. and Sluder, Ann E.} }