Faculty and Staff Directory
Alissa Richmond Armstrong
College of Arts and Sciences
|Office:||Jones Physical Science, Room 619|
The Armstrong laboratory's overarching goal is to understand how communication with adipocytes coordinates the response of adult stem cell populations and their differentiating daughters to changes in an organism’s nutritional input.
Adult stem cells play a key role in tissue homeostasis and damage repair. While many stem cell-supported tissues are affected by changes in diet, age, stress and hormone levels, it is unclear how adult stem cells cooperate with other tissues to ensure appropriate cellular responses to whole-body physiological state. Given the current obesity epidemic and the association between obesity and increased risk for several disease states including type 2 diabetes and cancer, the Armstrong lab is interested in understanding how nutritional sensing by adipocytes affects adult stem cells and their progeny. In addition to the incredible genetic tractability of Drosophila melanogaster (the fruit fly), several features make this organism a powerful model system for addressing how multiple organs coordinate the response of stem cells to nutritional status:
1) The dramatic ovarian response to diet, altered egg production, is mediated largely by effects on ovarian stem cells and their progeny.
2) Well-characterized adult stem cell populations support multiple organs, including the ovary, gut and testis.
3) Drosophila use organs analogous to those employed by mammals to regulate physiology.
4) Many nutrient sensing pathways and components, like insulin and TOR-mediated signaling, are highly conserved between mammals and fruit flies.
5) Well-established genetic tools allow for tissue and temporal specific manipulations.
My postdoctoral studies have shown that distinct nutrient sensing pathways function within adipocytes to regulate various processes along the stem cell lineage in the ovary. Using Drosophila melanogaster, the Armstrong lab takes advantage of genetic, molecular and cell biological tools to understand the mechanisms that underlie the control of adult stem cells by remote nutrient sensing.
Armstrong, AR., Laws, KM., Drummond-Barbosa, D. (2014). 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 141, 4479-4488.
Armstrong, A., Ryu,Y., Chieco, D., and Kuruvilla, R. (2011). Frizzled3 is required for neurogenesis and target innervation during sympathetic nervous system development. J Neurosci 31, 2371-2381.
Ascano, M., Richmond, A., Borden, P., and Kuruvilla, R. (2009). Axonal targeting of Trk receptors via transcytosis regulates sensitivity to neurotrophin responses. J Neurosci 29, 11674-11685.
Bodmer, D.*, Levine-Wilkinson, S.*, Richmond, A., Hirsh, S., and Kuruvilla, R. (2009). Wnt5a mediates nerve growth factor-dependent axonal branching and growth in developing sympathetic neurons. J Neurosci 29, 7569-7581. *co-first authors, contributed equally to this work
Chatterjee, I., Richmond, A., Putiri, E., Shakes, D. C., and Singson, A. (2005). The Caenorhabditis elegans spe-38 gene encodes a novel four-pass integral membrane protein required for sperm function at fertilization. Development 132, 2795-2808.