Unique features of a global human ectoparasite identified through sequencing of the bed bug genome

Abstract

The bed bug, Cimex lectularius, has re-established itself as a ubiquitous human ectoparasite throughout much of the world during the past two decades. This global resurgence is likely linked to increased international travel and commerce in addition to widespread insecticide resistance. Analyses of the C. lectularius sequenced genome (650 Mb) and 14,220 predicted protein-coding genes provide a comprehensive representation of genes that are linked to traumatic insemination, a reduced chemosensory repertoire of genes related to obligate hematophagy, host–symbiont interactions, and several mechanisms of insecticide resistance. In addition, we document the presence of multiple putative lateral gene transfer events. Genome sequencing and annotation establish a solid foundation for future research on mechanisms of insecticide resistance, human–bed bug and symbiont–bed bug associations, and unique features of bed bug biology that contribute to the unprecedented success of C. lectularius as a human ectoparasite.

The mitogenome of the bed bug Cimex lectularius (Hemiptera: Cimicidae)

“…It is an obligate ectoparasite that primarily feeds on human blood in a hematophagic lifestyle, but will readily feed on many bird and mammalian species as well (Usinger 1966). The insecticide-susceptible laboratory strain Har-73 (= Harlan) of C. lectularius was used for whole-genome shotgun sequencing and sequence assembly de novo , performed by two independent research groups: one in New York City, based primarily at the American Museum of Natural History (AMNH) and Weill Cornell Medicine (WCM) (Rosenfeld et al 2016), and another one at Baylor College of Medicine (BCM) as part of the i5k genome sequencing initiative (http://www.arthropodgenomes.org/wiki/i5K) (Benoit et al 2016). Specimens are kept in the AMNH Invertebrate Zoology collection and stored in liquid nitrogen in the Ambrose Monell Cryo Collection (AMCC).…”

Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle–plant interface

“…None of these HGT candidates showed significant expression in RNA-seq reads for adult males, females, or larvae, although this does not rule out expression in other stages or tissue-specific expression of these candidates below detection in whole organism RNA-seq. Recent insertions have similarly been detected in other arthropod genomes using the DNA-based pipeline [24, 25]. In contrast, the GH HGTs are more ancient insertions that have evolved into functional genes [26–30] (see results from in vitro functional characterization, discussed in section titled Plant cell wall degradation).…”

“…We manually annotated 11 putative endo- and exoglucanases (cellulases), members of GH9, subfamily 2 of GH5, GH45, and GH48, and 18 GH28 genes encoding putative pectin-degrading polygalacturonases. Previous work has shown that a number of GH family genes have been acquired from microbes by HGT (e.g., [24–30]; Table 1), and Fig. 4 shows the distribution of these and endogenous GHs in the 15 arthropod genomes studied herein.…”

Feel the heat: Activation, orientation, and feeding responses of bed bugs to targets at different temperatures

“…Future studies should investigate the sensory structures that bed bugs use to perceive heat (and cold), their distribution on the body of the bed bug, and the genes that encode the thermal receptors. The recently sequenced C. lectularius genome (Benoit et al, 2016;Rosenfeld et al, 2016) should expedite these investigations. In addition, future work should elucidate the interactions of host-produced heat with other host cues, including CO 2 and body odors, and the orientation patterns of bed bugs at different spatial alignments with the host.…”