Proposal for the Sequencing of a New Target Genome: White Paper for a Human Body Louse Genome Project.

Barry R. Pittendrigh, John M. Clark, J. Spencer Johnston, Si Hyeock Lee, Jeanne Romero-Severson, Gregory A. Dasch
J. Craig Venter Institute (JCVI)

The human body louse, Pediculus humanus humanus, is the primary vector which transmits the bacterial agents of louse-borne relapsing fever, trench fever, and epidemic typhus. Epidemic typhus, one of the most significant historical diseases of humans, is caused by Rickettsia prowazekii, a category B bioterrorism agent that can cause persistent human infection. Besides its notoriety as the agent of the recurrent chronic disease, trench fever, Bartonella quintana can cause endocarditis and is a common infection among the homeless. Borrelia recurrentis causes another recurrent fever in central and Eastern Africa that is characterized by significant morbidity and mortality. The genome sequences of R. prowazekii and B. quintana have been determined as well as those of two species of Borrelia so that determining the body louse genome will enhance studies of host-vector-pathogen interactions. Body lice and the closely related human head louse, Pediculus humanus capitis, belong to the hemimetabolous order Phthiraptera. Head lice represent a major economic and social concern in North America, because head lice infestations are often associated with school-aged children, who miss substantial school days during this critical learning period. Resistance to traditional pesticides used to control head and body lice have developed. It is imperative that new molecular targets are discovered to aid in development of novel compounds to control these insects. No complete genome sequence has been obtained for a hemimetabolous insect species. In large part, this is because hemimetabolous insects often have large (2000 Mb) to very large (up to 16,000 Mb) genomes. Recently, we discovered that the body louse genome is one of the smallest known in the insect world, 107.6 + 0.6 Mb for males and 105.4 +0.7 Mb for females, making it an ideal hemimetabolous insect for a genome sequencing project. We currently have made EST libraries for both body and head lice which are being sequenced by a consortium of scientists from Purdue University, University of Massachusetts at Amherst, and Seoul National University. Additionally, we have available (i) a highly inbred strain of body lice that can be used in a genome sequencing project, (ii) the financial resources to help with the creation of a BAC library if needed for the genome project, and (iii) means to generate EST libraries of body lice after exposure to bacterial pathogens and pesticides.