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Andrew Spracklen


andrew-spracklen@uiowa.edu
Mentor: Tina Tootle, Ph.D.
Lab Room: 1-500 BSB
Lab Phone: 319-335-7713

Dissecting the mechanisms by which prostaglandins regulate actin dynamics

Prostaglandins (PGs), small bioactive lipids, are synthesized at their sites of action by cyclooxygenase (COX) enzymes and mediate a wide array of biological activities including pain, inflammation, fertility, immune function, and cancer progression (both tumor growth and metastasis). Recently, Dr. Tootle has identified the Drosophila COX1 enzyme, Pxt, and has demonstrated that both genetic loss of Pxt as well as pharmacologic inhibition of COX1 activity disrupts Drosophila oogenesis by blocking nurse cell dumping, an actin dependent processes required for follicle maturation, thus providing a novel model for exploring the function of prostaglandins and their downstream signaling pathways utilizing both genetic and pharmacologic approaches. Lasting just thirty minutes, Drosophila nurse cell dumping is a highly dynamic process requiring spatial and temporal coordination of active actin cytoskeletal remodeling in order for the nurse cells to supply their cytoplasmic contents to the oocyte. These dynamic processes are highlighted by rapid assembly of cytoplasmic actin filament bundles and increases in cortical actin. Preliminary data indicates that PG signaling is involved in both the temporal and spatial control of these actin structures. My goals are to 1) Characterize the enzymatic activity of Pxt, 2) Determine how PG signaling acts to spatially and temporally regulate actin dynamics and 3) Determine the mechanism by which PG signaling facilitates rapid actin cytoskeletal rearrangements.

Publications:

Groen, CM*, Spracklen AJ*, Fagan TN, Tootle, TL. (2012) Fascin – a novel downstream target of prostaglandin signaling during actin remodeling. Molecular Biology of the Cell. [Epub ahead of print]. * Denotes shared first authorship. 2012.

Spracklen A, Tootle TL. The utility of stage-specific mid-to-late Drosophila follicle isolation. JoVE. In press.

Abstracts:

Spracklen AJ, Tootle TL. Drosophila Nurse Cell Dumping: A Novel Model for Interrogating Prostaglandin Signaling. Midwest Drosophila Conference, 2010.

Spracklen AJ, Tootle TL. Drosophila Nurse Cell Dumping: an In Vivo Model for Prostaglandin-Dependent Actin Remodeling. American Society for Cell Biology Annual Meeting, 2010.

Spracklen AJ, Tootle TL. Drosophila Nurse Cell Dumping: A Novel Model for Interrogating Prostaglandin Signaling. University of Iowa Molecular and Cellular Biology Retreat, 2010.

Spracklen, AJ, Tootle, TL. Drosophila Nurse Cell Dumping: An in vivo Model for Prostaglandin-Dependent Actin Remodeling. University of Iowa Health Sciences Research Week, 2011.

Spracklen AJ, Tootle TL. Characterizing the Enzymatic Function of Pxt, the Drosophila Prostaglandin G/H Synthase 1. Lipid Maps Meeting, 2011.

Spracklen AJ, Tootle TL. Characterizing the Enzymatic Function of Pxt, the Drosophila Prostaglandin G/H Synthase 1. Gordon Research Conference on the Molecular Biology of Lipids, 2011.



Honors and Awards

  • MCB Scientists’ Survival Skills Seminar Committee
  • 2010 MCB Retreat Travel Award for best poster
  • 2010 American Society for Cell Biology Pre-Doctoral Travel Award
  • 2010 NIH T32 Pharmacologic Sciences Training Grant
  • 2010-Present Member American Society for Cell Biology
  • AAAS members through the AAAS/Science Program for Excellence in Science
  • NIH T32 Pharmacologic Sciences Training Grant
  • Outstanding Teaching Assistant Award Winner - 2014