Tissue stem cells require intrinsic and local regulators; however, it is their ability to sense and respond to changes in whole-body physiology and nutrient availability that allows them to function in harmony with varying demands and constraints faced by multicellular organisms. We pioneered using Drosophila melanogaster as a model to study adult stem cell regulation by diet, and identified cellular and molecular pathways that link diet to stem cells. Drosophila offers many advantages as a model system, including highly evolutionarily conserved developmental and metabolic processes, and well-characterized stem cells. In particular, we take advantage of the germline stem cell (GSC) lineage in the Drosophila ovary, where one can readily identify GSCs and quantify self-renewal, proliferation, differentiation and survival along their lineage. Our research showed that GSCs and their progeny divide and grow faster on a rich diet, partially via insulin, steroid hormone, and Target of Rapamycin (a nutrient sensor) signaling in the ovary. More recently, we showed that adipocytes also contribute to the GSC response to diet, which is particularly relevant in light of the current obesity epidemic and the link between dysfunctional adipocytes and a number of diseases, including cancers. We are currently investigating the mechanisms underlying adipocyte-GSC lineage communication, and we are also exploring the connection between brain signals (involved in sensing a variety of environmental and physiological stimuli) and stem cell function. Our more recent work opens a new frontier in our research, aimed at elucidating how multiple organs communicate with each other to orchestrate a cogent response of the organism as a whole to changing conditions.
Armstrong AR, Laws KM, Drummond-Barbosa D. Adipocyte amino acid sensing controls adult germline stem cell number via the amino acid response pathway and independently of Target of Rapamycin signaling in Drosophila. Development. 2014 PMID: 25359724.
Ables ET, Drummond-Barbosa D. The steroid hormone ecdysone functions with intrinsic chromatin remodeling factors to control female germline stem cells in Drosophila. Cell Stem Cell. 2010 PMID: 21040900.
LaFever L, Feoktistov A, Hsu HJ, Drummond-Barbosa D. Specific roles of Target of rapamycin in the control of stem cells and their progeny in the Drosophilaovary. Development. 2010 PMID: 20504961.
Hsu HJ, Drummond-Barbosa D. Insulin levels control female germline stem cell maintenance via the niche in Drosophila. Proc Natl Acad Sci U S A. 2009 PMID: 19136634.
LaFever L, Drummond-Barbosa D. Direct control of germline stem cell division and cyst growth by neural insulin in Drosophila. Science. 2005 PMID: 16099985.