Logo for University of Iowa Health Care This logo represents the University of Iowa Health Care

Andrew Spracklen

Mentor: Tina Tootle, PhD

Year Entered Into Program: 2009

PhD Institution: University of Iowa, 2014

Affiliations

  • Molecular and Cellular Biology Graduate Program

Research Description

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 theDrosophila 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.

Publication(s)

  1. Spracklen, A.J., Fagan, T.N., Lovander, K. and Tootle, T.L.:  The pros and cons of common actin labeling tools for visualizing actin dynamics during Drosophila oogenesis. Dev Biol 393, 209-226, 2014.  PMCID: PMC4438707
  2. Spracklen, A.J., Kelpsch, D.J., Chen, X., Spracklen, C.N. and Tootle, T.L.:  Prostaglandins temporally regulate cytoplasmic actin bundle formation during Drosophila oogenesis. Mol. Biol. Cell 25(3):397-411, 2014.  PMCID: PMC3907279  [Selected for the cover of the February 1, 2014 issue]
  3. Spracklen, A.J. and Tootle, T.L.:  The utility of stage specific mid-to-late Drosophila follicle isolation. Journal of Visualized Experiments. 2(82):50493, 2013.  PMCID: PMC4011191        
  4. Groen, C.M.*, Spracklen, A.J.*, Fagan, T.N., Tootle, T.L.:  Drosophila fascin is a novel downstream target of prostaglandin signaling during actin remodeling. Molecular Biology Cell. 23(23):4567-4578, 2012.  * Denotes shared first authorship.  PMCID: PMC3510018

Award(s)

  • American Society for Cell Biology Predoctoral Travel Award, 2010
  • Molecular and Cellular Biology Retreat Travel Award for Best Poster, 2010
  • Fellowship appointment on the Pharmacological Sciences Training Program (NIH T32 GM067795), University of Iowa, 2010-2012
  • Molecular and Cellular Biology Retreat Travel Award for Best Presentation, 2012
  • National Science Foundation, 2012
  • University of Iowa Graduate Student Travel Grant, 2014
  • University of Iowa Executive Council of Graduate & Professional Students Travel Grant, 2014
  • Tung-Yang Wing Award for Superior Achievement in Anatomy and Cell Biology Graduate Education - achievement based award given in recognition of outstanding research achievement during the past year, 2014
  • Outstanding Teaching Assistant Award – awarded by the University of Iowa Council on Teaching to selected teaching assistants nominated by students, faculty, colleagues, departmental executive officers, or deans for having demonstrated outstanding ability as teachers, 2014

Awards since graduating from U of IA

  • Individual Postdoctoral Fellowship (F32 GM117803), NIH/NRSA, Defining how Abelson Kinase Regulates Cell Adhesion and Actin Dynamics, 2016-2018
  • Fellowship appointment, Basic Mechanisms of Viral and Chemical Carcinogenesis Training Grant (T32 CA009156), NIH/NCI, University of North Carolina School of Medicine Lineberger Comprehensive Cancer Center, 2014-2015