NEW YORK (GenomeWeb News) – A four-institution study intended to improve understanding of the evolution, developmental biology, and physiology of insects is among 10 multidisciplinary, multiple-location research programs or "units" that have been awarded a combined €22.2 million over three years by the Senate of Germany's Deutsche Forschungsgemeinschaft, also known as DFG or the German Research Foundation.
The goals of "iBeetle: Functional Genomics of Insect Embryogenesis and Metamorphosis" include using a genome-wide RNA interference screen to identify the respective genes in red brown flour beetles, also known as Tribolium castaneum.
"The main impact of this research unit will be to establish Tribolium as alternative insect model system for genomic approaches — hence, we hope that the impact goes far beyond the specific projects proposed within the unit," Gregor Bucher, junior professor of developmental genetics at Georg-August-Universität Göttingen in Germany, told GenomeWeb Daily News on Tuesday.
The study will go beyond past research by Bucher and collaborating researchers from Germany and the US. That work has included identifying new genes involved in head development through an RNAi screen, identifying head mutants from the "GEKU" insertional mutagenesis screen.
GEKU is an acronym whose letters comprise the first letters of the collaborating institutions of the PI's involved: Ernst Wimmer's lab at the University of Göttingen, Martin Klingler's lab at Germany's Friedrich-Alexander-Universität Erlangen-Nürnberg; Sue Brown's lab at Kansas State University; and Dick Beeman's lab at the US Department of Agriculture's Center for Grain and Animal Health Research, formerly the Grain Marketing and Production Research Center.
For the new study, six investigators from the institutions will join to perform the iBeetle screen, with each researcher receiving funding for one PhD student. According to Bucher, the students will join to perform the screening during the first year at Erlangen and Göttingen, where they will screen each gene for a variety of phenotypes that include muscles and brain, to be marked by green fluorescent protein; cuticle phenotypes of L1 larva and Pupa; sterility and metamorphosis regulation.
"Half the genome will be screened in the first phase which has been funded right now. After the screening year they choose their favorite phenotype from the entire data set depending on the scientific interest of the respective PI," Bucher said.
The red flour beetle was selected for the head development study because it has a typical insect head, without the involution of the Drosophila larval head, turned outside in the thorax, that has impeded thorough investigation, Bucher said.
As a result, he said, several research areas that are hard to perform in Drosophila will be carried out in the new project using Tribolium. These include:
• Embryonic patterning, including the head, legs, segmentation, dorsoventral patterning, and axis formation.
• Development of embryonic leg muscles, since Drosophila does not have embryonic legs.
• Development of the ovary and of somatic stem cells within ovary development.
• Patterning during metamorphosis, which Bucher termed crucial to understanding the evolution of insect diversity.
"It is the second best insect model organism in terms of techniques that are available," many of them pioneered by members of the consortium alone or together with their US collaborators, Bucher explained. Those techniques, he added, include the use of RNA interference, transgenesis, transposon-mediated screen, heat-shock and UAS/Gal4 mediated systems for misexpression.
In past Tribolium research, Bucher said, he has successfully screened candidate genes for head phenotypes, after starting with the presumption that a gene was involved because it was so for Drosophila or mice, or because some long-known signaling pathways were involved, such as Wnt or hedgehog. But in that research, he has also encountered a major drawback: While some genes of interest have been found, many others have been missed.
"The iBeetle screen overcomes this limitation because we will find all genes required for this process in a hypothesis independent approach. In the case of the head, no complete gene set is known because Drosophila has turned difficult to screen. So for my project, it essentially means that I will get to know all genes required for head development, which is of course a perfect starting point to reveal the network," Bucher said.
Martin Klingler of FAU in Erlangen will work on using the iBeetle screen to reveal the unknown genes that explain segmentation in Tribolium.
The German Research Foundation now funds a total of 209 research units, most of which are scheduled to run for about six years.