Research Abstracts Online
January 2010 - March 2011
University of Minnesota Twin Cities
College of Biological Sciences
of Genetics, Cell Biology, and Development
PI: Michael B. O'Connor
Transcriptional Targets of TGF-beta (Activin) Signaling in Drosophila
Ability to coordinate growth and energy homeostasis in response to changes in nutrient status is vital for the survival, growth and development of most multicellular organisms. The fruit fly Drosophila melanogaster manifests a reproducible fast growth pattern in a range of nutritional conditions indicating the presence of a robust metabolic regulation and feedback network that links nutrient availability to growth and development. Work in this lab shows that this ability is lost in flies that lack the TGF-beta (Activin) ligand dawdle (daw) or the intracellular transducer of TGF- signaling smox. While wild-type animals show rapid growth patterns on both standard Drosophila food and protein rich yeast paste, daw and smox mutants (daw32 and smoxnull) grow well only on yeast paste and fail to survive on standard food. Moreover, daw seems to negatively regulate one of the Drosophila insulin-like peptides, dIlp6, indicating a potential role of TGF-signaling in regulating metabolism. Expression pattern of daw in the larval stages also support this possibility. daw is expressed in the fat body, gut, and oenocytes, tissues that play a vital role in regulating metabolism and energy homeostasis in Drosophila.
In light of these observations, these researchers performed Affimatrix microarrays to compare gene expression profiles in four different tissues (fat body, gut, body wall, and salivary gland) across three different genotypes (daw32, smoxnull, and wild-type). They expect that a comparison of the gene expression profiles in these tissues between daw32 or smoxnull and wild-type animals will allow them to make an educated guess about the genes that may be regulated by activin signaling.
Arpan Ghosh, Graduate Student