The very thought of them makes a person shudder – and scratch. Those bloodsucking bed bugs are endemic in every major city, and they're very hard to get rid of. A massive international research partnership – including the University of Cincinnati – has sequenced the entire genome of the common bed bug, uncovering several traits that also could reveal why they're so resistant to pesticides. The article is one of two papers sequencing the bed bug gene that is published this month in the journal, Nature Communications.
The intensive analysis of the common bed bug (C. lectularius) sequenced genome (650 Mb) and 14,220 predicted protein-coding genes. The investigation provides a comprehensive representation of genes linked to the bed bugs' mating traits (traumatic insemination). The examination also reveals a reduced chemosensory repertoire of genes related to making them the little blood suckers that they are, as well as several qualities that can make them resistant to pesticides. "We provide the first full panel of all the potential genes that are likely involved with pesticide resistance," says lead author Joshua Benoit, a UC assistant professor of biological sciences.
The massive analyses involved rearing the bed bugs, extracting DNA and sequencing and assembling the genome. The report provides a full annotation of genes that compose the bed bug cuticle, or their outer skeleton. That tough outer shell plays a significant role in their resistance to pesticides. It's believed that resistance is a result of changes in the expression of cuticle proteins. The researchers identified 273 genes that encode common cuticle proteins.
"We found underlying characteristics surrounding why they feed off only blood," says Benoit, who adds that the bed bug can survive an entire year without a meal. In other words, if someone's home is infested and that person leaves the premises for a few weeks in the hope that the bed bugs will go away, that isn't going to happen. The bed bugs will be hungry and waiting when the "host" gets back home.
The genome examination revealed what chemical cues attract the bed bug and genes associated with blood digestion.
The profile also found the gene related to how bed bugs mate, which is through what's called traumatic insemination. The male pierces an area in the female that is not a reproductive organ, yet she will develop a new, auxiliary reproductive organ to accommodate that form of reproduction.
"They seem to be uniquely central to lateral gene transfers from bacteria," adds Benoit. "We picked up more than 800 putative lateral gene transfer bits." That included Wolbachia bacteria, a common reproductive parasite, and Arsenophonus.
"Parts of the genome from this bacteria have been inserted into the bed bug genome," explains Benoit. "This happens once or twice in a lot of incidences, but having it happen a hundred times is unique. And one specific gene is even expressed."
International research institutions on this project represent the U.S., India, Germany, Switzerland, France, Taiwan, New Zealand and the United Kingdom.
"This study reveals evolutionary adaptations associated with the lifestyle of bed bugs, including significant reductions in chemosensory genes, expansion of genes that are associated with blood digestion, and the entire repertoire of genes that have been associated with pesticide resistance in various other species. The sequencing, assembly, annotation and manual analyses of the C. lectularius genome provide an important and timely resource for understanding the biology of this human ectoparasite. It will also serve as a gateway for the discovery of new targets for control of bed bug populations," concludes the paper.
Funding for the genome sequencing, assembly and automated annotation was provided by National Human Genome Research Institute (NHGRI) grant U54 HG003273. Additional funding was supported by the Blanton J. Whitmire endowment, Housing and Urban Development; National Science Foundation; Alfred P. Sloan Foundation; National Institutes of Health; the Royal Society of New Zeland Marsden Fast Start Grant; Fralin Life Sciences Institutes and Virginia Agriculture Experimental Station; European Research Council; Deutsche Forschungsgemeinschaft; UC Faculty Development Research Grant and Ohio Supercomputer Center; Marie Curie International Outgoing Fellowships; and Swiss National Science Foundation.
The journal Nature Communications is an open access journal that publishes high-quality research from all areas of the natural sciences. Papers published by the journal represent important advances of significance to specialists within each field.
International Bed Bug Genome Project Collaboration
University of Cincinnati Department of Biological Sciences
Joshua Benoit; Elise M. Szuter, doctoral student; Emily C. Jennings, doctoral student; Andrew Rosendale, post-doctoral fellow; Jacob Hendershot, undergraduate; Richard W. Hagan, undergraduate.
University of Kentucky Department of Entomology
Subba R. Palli, Hemant Gujar, Jayendra Nath Shukla, Fang Zhu
Washington State University Department of Entomology
ICAR – National Bureau of Agricultural Insect Resources, Indian Council of Agricultural Research
University of Tennessee Health Sciences Center, Memphis, Department of Microbiology, Immunology and Biochemistry
David R. Nelson
Virginia Tech Fralin Life Institute and Department of Entomology
Zach N. Adelman; Michelle A.E. Anderson
University of Cologne (Germany), Cologne Biocenter and Zoological Institute
Wolfgang Blenau; Christian Derst; Reinhard Predel
Goethe University Frankfurt (Germany), Institut für Bienenkunde (Polytechnische Gesellschaft)
Valentina Resnik; Sebastian Wernig
University of Würzburg (Germany), Theodor-Boveri-Institute, Biocenter, Department of Neurobiology and Genetics
Pamela Menegazzi; Nicolai Peschel; Christian Wegener
Technische Universitaet Dresden (Germany), Department of Biology, Applied Zoology
Institute of Biology, Freie Universitaet (Germany), Department of Evolutionary Biology
Paul R. Johnson
University of Geneva (Switzerland), Department of Genetic Medicine and Development and Swiss Institute of Bioinformatics
Panagiotis Ioannidis'; Robert M. Waterhouse; Evgeny M. Zdobnov
Massachusetts Institute of Technology and The Broad Institute of MIT and Harvard, Computer Science and Artificial Intelligence Laboratory
Robert M. Waterhouse
Pest Control Biology and Research Technologies, Bayer CropScience AG (Germany)
Ralf Nauen; Corinna Schorn; Mark-Christoph Ott; Frank Maiwald
Texas A&M University, Department of Entomology
J. Spencer Johnston; Edward L. Vargo
North Carolina State University, Raleigh, Department of Entomology and W.M. Keck Center for Behavioral Biology
Purdue University, Department of Entomology
Hugh M. Robertson
University of Florida, Gainesville, Department of Entomology and Nematology
Benjamin A. Hottel
Institut de Génomique Fonctionnelle de Lyon (IGFL, France), Ecole Normale Supérieure de Lyon
David Armisén; Antonin Jean Johan Crumière; Peter Nagui Refki; Maria Emilia Santos; Essia Sghairer; Séverine Viala; Abderrahan Khila
Max Plank Institute for Chemical Ecology (Germany), Department of Entomology
National Agricultural Library, Beltsville, Maryland
Monica Poelchau; Christopher Childers; Chien-Yueh Lee; Han Lin
National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics
Chien-Yueh Lee; Han Lin
University of Otago (New Zealand), Department of Biochemistry and Genetics Otago
Elizabeth J. Duncan
University of Rochester, Department of Biology
John H. Werren; Amanda Dolan
Baylor College of Medicine, Human Genome Sequencing Center, Department of Human and Molecular Genetics
Stephen Richards; Daniel S.T. Hughes; Shwetha C. Murali; Jiaxin Qu; Shannon Dugan; Sandra L. Lee; Hsu Chao; Huyen Dinh; Yi Han; HarshaVardhan Doddapaneni; Kim C. Worley; Donna M. Muzny; Richard A. Gibbs
Massey University (New Zealand), Institute of Fundamental Science
University of Cologne (Germany), Institute for Developmental Biology
Kristen A. Panfilio; Iris M. Vargas Jentzsch
University of Tulsa, Department of Biological Sciences
Wayne State University, Department of Biological Sciences
Markus Friedrich; Jeffery W. Jones
Center for Autoimmune Genomics and Etiology, Division of Biomedical Informatics and Division of Developmental Biology, Cincinnati Children's Hospital Medical Center (CCHMC), Department of Pediatrics, UC College of Medicine
Matthew T. Weirauch
The Ohio State University (Wooster), Department of Entomology
Omprakash Mittapalli; Chaoyang Zhao
Department of Biological Chemistry and Crop Protection, Rothamsted Research, BBSRC Harpenden, Herts, AL5 2JQ, United Kingdom
Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Disease, Bethesda, Maryland
Jose M. C. Ribeiro
U.S. Department of Agriculture – Agricultural Research Service Bee Research Laboratory, Beltsville, Maryland
Jay D. Evans
Yale University, Department of Epidemiology of Microbial Diseases, Yale School of Public Health
Geoffrey M. Attardo