Digestive Health Center

  • Obesity and the Digestive System

    Brian Gebelein, PhD
    Assistant Professor
    Department of Pediatrics; Division of Developmental Biology
    Visit the Gebelein Lab site.

    Description of Research

    The central pathways that regulate caloric intake and the metabolic processes that control organismal growth are well conserved across multicellular organisms. The genetically tractable fruit fly, Drosophila melanogaster, is one of the best characterized model organisms to investigate how the nervous, endocrine, and digestive systems communicate to regulate energy metabolism at the organismal level. The Gebelein lab has recently identified a small cluster of uncharacterized secretory and neural cells essential for proper growth control in Drosophila. These growth control cells (GC-cells) form early in embryogenesis and are distinct from, but in close proximity to, hormone-producing cells known to regulate energy metabolism. Using novel genetic tools generated in his lab, he found that the targeted ablation of GC-cells results in a severe growth defect and lethality. In addition, he found that while GC-ablated flies fail to grow normally, they are capable of ingesting and clearing food through their digestive tracts. More recent findings indicate that the GC cells are essential for regulating normal feeding behavior. Ongoing genetic ablation studies coupled with microarray analysis and metabolic profiling aim to identify key genetic pathways regulated by the GC cells.  

    Collaborations

    Dr. Gebelein is actively using the Gene and Protein Expression Core and the Bioinformatics Core in collaboration with Dr. Potter to interrogate the genetic pathways altered in flies lacking growth control cells.

 
  • Research image.

    click to enlarge

    Research image.

    C. Control larva (1 at left) and GC-ablated larva (three DT-1 individuals at right) were starved for 1 hour then fed blue-dyed food for 1 hr. D. Larvae from C were transferred to non-dyed food for 2 hrs than imaged. E. Larval growth assays of 15 controls, and 15 GC-ablated larvae with either Grim (weak) or DT-1 (strong) were scored for length. * Denotes P-value < 0.001; ** denotes P-value < 0.0001. Preliminary data presented in Pilot and Feasibility application.