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Red flour beetle (Tribolium castaneum)
Tribolium is a globally distributed pest of stored grain and grain products, and the number one arthropod vector of vertebrate tapeworm, as well as a model for other pest beetles. For many decades, it was used to study insecticide resistance and population genetics/ecology, but genetic studies were rudimentary. During the last fifteen years, through efforts at Kansas State University and by collaborators in Germany, tremendous progress has been made, and Tribolium is now considered the second most powerful insect experimental system (after Drosophila) for genetic and molecular studies. In Manhattan, that effort has been led by Richard Beeman (USDA and ancillary faculty member of KSU), Rob Denell, and Susan Brown (Biology). Collectively, these
investigators have generated more than 50 papers on Tribolium, including those in such prestigious journals as Nature (2), Science, and Proceedings of the National Academy of Sciences. They currently have active extramural grants totaling ca. $3M for their Tribolium research. The status of Tribolium as an experimental system is demonstrated by its choice by the National Institutes of Health as the fourth insect genome to be sequenced (after two Drosophila species, the malaria mosquito, and the honeybee). This sequencing effort, which cost over $2M, resulted from a proposal written by Brown and colleagues.
Until recently, the power of the Tribolium system has been utilized for experimental studies with two major foci. Beeman’s group has concentrated on the acquisition of insecticide resistance, while the Brown/Denell/Beeman group has utilized the insect for developmental genetic studies relevant to our understanding of the evolution of genetic mechanisms. More recently, other K-State faculty members have undertaken Tribolium studies.
Karl Kramer (USDA/Biochemistry), Michael Kanost (Biochemistry), Subbaratnam Muthukrishnan (Biochemistry) and Richard Beeman have two current and one pending NSF awards/proposal to study chitin
metabolism and cuticle scleritization. Entomology faculty member
Yoonseong Park studies neuropeptide and other hormone receptors, Rollie Clem (Biology) is assessing apoptosis, and Tonia Von Ohlen (Biology) is studying neurogenesis.
Brenda Oppert (USDA/Entomology) is using
high-throughput sequencing to determine differences in
the midgut of coleopteran pests that ingest plant or
bacterial toxins. Information from these
experiments will be used to define toxin mode of action
in coleopterans and also to provide new information on
genes specific to the coleopteran gut.
Tribolium paper published in
Nature.
The genome of the model
beetle and pest
Tribolium castaneum
Tribolium
Genome Sequencing Consortium
Nature
452,
949-955(24 April 2008)
doi:10.1038/nature06784
Download PDF of article.
Tribolium castaneum is a member of the most species-rich
eukaryotic order, a powerful model organism for the
study of generalized insect development, and an
important pest of stored agricultural products. We
describe its genome sequence here. This omnivorous
beetle has evolved the ability to interact with a
diverse chemical environment, as shown by large
expansions in odorant and gustatory receptors, as well
as P450 and other detoxification enzymes. Development in
Tribolium is more representative of other insects than
is Drosophila, a fact reflected in gene content and
function. For example, Tribolium has retained more
ancestral genes involved in cell–cell communication than
Drosophila, some being expressed in the growth zone
crucial for axial elongation in short-germ development.
Systemic RNA interference in T. castaneum functions
differently from that in Caenorhabditis elegans, but
nevertheless offers similar power for the elucidation of
gene function and identification of targets for
selective insect control.
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