First beetle genome sequenced (3/26/2008)

Red flour beetle

Sequencing the genome of the red flour beetle, also known as Tribolium castaneum, could prove of double benefit - both in understanding how organisms develop and in fighting the insect pest, said a researcher at Baylor College of Medicine in Houston who was part of the international consortium that published the genetic sequence in the current issue of the journal Nature.

On one hand, the red beetle is a voracious pest with an appetite that destroys millions of dollars worth of grain stored in flour-mills. On the other, the beetle serves as a model for studying the genetics of development - much in the way that scientists study fruit flies or Drosophila to understand how genes can affect the ways in which organisms grow, said Dr. Stephen Richards, assistant professor in the Baylor College of Medicine Human Genome Sequencing Center. Dr. Richard Gibbs of BCM directs the center.

A peek at pest biology

"The Tribolium genome sequence is the first for any beetle," said Dr. Dick Beeman, a research entomologist with the U.S. Department of Agriculture Agricultural Research Service in Manhattan, Kansas. "Since beetles are the most diverse and successful animals on earth, this is an important milestone in evolutionary biology. Also, Tribolium is the first significant agricultural pest insect to have its genome revealed, and this creates new opportunities for understanding and exploiting pest biology."

"The genome sequence in combination with the ability to perform RNAi (a method that inhibits gene expression) at virtually any life stage makes Tribolium a premier insect model organism for studies that are not as readily accessible in Drosophila," said Dr. Susan J. Brown, professor of biology at Kansas State University. "It's really exciting to see the burst of activity in Tribolium studies that has accompanied the sequencing project."

The sequencing effort took the talents of 100 scientists from 14 countries, all of whom participated in the Tribolium Genome Sequencing Consortium. The three-year project sped along, buoyed by the high through-put sequencing that is a hallmark of the BCM Genome Sequencing Center, which has led the sequencing efforts for the human genome as well as several model organisms.

Shared ancestry?

Richards said that some of the genes found in the beetle apparently share ancestry with similar genes in humans. For example, the gene for the receptor for vasopressin, which regulates how water is stored in the body, shares the same ancestry as the gene for the same hormone in humans.

"These beetles are good at living in dry environments," said Richards. "They survive partially on metabolic water, but 10 percent humidity in their environment is enough."

Beeman agreed, saying "As just one example, more than 100 interesting genes associated with the exoskeleton have been identified, and many of these have been shown to have specific, vital functions. Tribolium has several attributes that make it unique among sequenced insects, including a preference for arid environments and a cosmopolitan palate."

"This independence of water makes Tribolium a prime-candidate for a companion as a research organism during the long-term space flight such as the one planned for the red planet Mars," said Dr. Reinhard Schröder of the University of Rostock, Germany, and a co-author of the study.

A consortium of researchers from many countries took part in this work, but Richards cited in addition to those above the efforts of Drs. Gregor Bucher of Georg August University in Göttingen, Germany; Roben Denell of Kansas State University in Manhattan, and Martin Klingler of Friedrich-Alexander-University in Erlangen, Germany, as key leaders in completing the sequence and its analysis.

Funding for this research came from the National Human Genome Research Institute and the U.S. Department of Agriculture.

Note: This story has been adapted from a news release issued by the Baylor College of Medicine

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