NEW YORK (GenomeWeb News) – An international team of researchers has sequenced — and started analyzing — the genome of the red flour beetle, an agricultural pest that lives in and snacks on stored grains and dried foods.
More than a hundred scientists from 14 countries pitched in to sequence the genome of the red flour beetle, Tribolium castaneum. The Trilobium Genome Sequencing Consortium reported the achievement in the advanced online publication of Nature yesterday.
Tribolium castaneum can survive extremely dry environments — as well as every class of insecticides humans have devised against it. But because it is amenable to genetic crosses and grows easily in the lab, with a short life cycle and high reproduction rates, T. castaneum is a good model organism, especially for developmental studies.
To sequence the T. castaneum genome, the researchers generated about one and a half million sequence reads at 7.3 times coverage. They assembled these into contigs totaling 152 megabases coding for 16,404 gene models. Thousands of these genes seem to be species-specific.
Interestingly, compared to fruit flies, mosquitoes, silkmoths, and honeybees, the red flour beetle genome has a “major expansion” of genes coding for smell- and taste-related proteins and receptors.
For instance, the team identified 265 odorant receptors, 220 gustatory receptors, and dozens more odorant and gustatory pseudogenes. The red flour beetle also shares most of the 21 vision-related genes previously identified in fruit flies, though the beetle is likely less able to discriminate between colors, the researchers said.
The T. castaneum genome also houses an expanded roster of cytochrome P450 genes — genes involved in metabolic detoxification, insecticide resistance, and environmental response. Overall, the authors report, the red flour beetle genome is consistent with the bug’s adaptation to a “dry, chemically diverse and toxin-rich microenvironment.”
The consortium suggests that identifying and understanding genes related to the flour beetle’s pesticide resistance, vision, smell, and taste could eventually aid researchers intent on controlling these and similar pests.
“[K]nowledge of all possible insecticide targets will aid greater selectivity in pesticide design, thereby mitigating possible side effects,” the authors wrote. “Finally, the true value of this sequence may be the entry it provides into the many and richly diverse facets of beetle biology, physiology and behavior.”
The work was funded by the National Institutes of Health and the US Department of Agriculture and was led by Baylor College of Medicine’s Stephen Richards, who is at that institution’s Human Genome Sequencing Center.