February 2, 2016 | News from Weill Cornell Medical College
Researchers Sequence First Bedbug Genome. Scientists have assembled the first complete genome of one of humanity’s oldest and least-loved companions: the bedbug. The new work, led by researchers at the American Museum of Natural History and Weill Cornell Medicine, and published Feb. 2 in Nature Communications, could help combat pesticide resistance in the unwelcome parasite. The data also provides a rich genetic resource for mapping bedbug activity in human hosts and in cities, including subways.
“Bedbugs are one of New York City’s most iconic living fossils, along with cockroaches, meaning that their outward appearance has hardly changed throughout their long lineage,” said one of the paper’s corresponding authors Dr. George Amato, director of the museum’s Sackler Institute for Comparative Genomics. “But despite their static look, we know that they continue to evolve, mostly in ways that make it harder for humans to dissociate with them. This work gives us the genetic basis to explore the bedbug’s basic biology and its adaptation to dense human environments.”
The common bedbug (Cimex lectularius) has been coupled with humans for thousands of years. This species is found in temperate regions and prefers to feed on human blood. In recent decades, the prevalence of heated homes and global air travel has accelerated infestations in urban areas, where bedbugs have constant access to blood meals and opportunities to migrate to new hosts. A resurgence in bedbug infestations since the late 1990s is largely associated with the evolution of the insects’ resistance to known pesticides, many of which are not suitable for indoor application.
“Bedbugs all but vanished from human lives in the 1940s because of the widespread use of DDT, but unfortunately, overuse contributed to resistance issues quite soon after that in bedbugs and other insect pests,” said Louis Sorkin, an author on the paper and a senior scientific assistant in the Museum’s Division of Invertebrate Zoology. “Today, a very high percentage of bedbugs have genetic mutations that make them resistant to the insecticides that were commonly used to battle these urban pests. This makes the control of bedbugs extremely labor intensive.”
The researchers extracted DNA and RNA from preserved and living collections, including samples from a population that was first collected in 1973 and has been maintained by museum staff members since then. RNA was sampled from males and females representing each of the bug’s six life stages, before and after blood meals, in order to paint a full picture of the bedbug genome.
When compared with 20 other arthropod genomes, the genome of the common bedbug shows close relationships to the kissing bug (Rhodnius prolixus), one of several vectors for Chagas disease, and the body louse (Pediculus humanus), which both have tight associations with humans.