The Role of Actin Cytoskeleton in Endocytosis and Exocytosis in the Salivary Glands of Live Rodents Public Deposited

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  • March 19, 2019
  • Masedunskas, Andrius
    • Affiliation: College of Arts and Sciences, Department of Biology
  • In the last two decades, mammalian cell biology has greatly benefited from major technological advances in light microscopy that have enabled imaging virtually any cellular process at different levels of resolution. However, mammalian cell biology has been studied primarily by using in vitro models. Cell culture models have been used the most, since it offers several advantages such as, being amenable to both pharmacological and genetic manipulations, reproducibility, and relatively low costs. However, their major limitation is that the architecture and physiology of cells in vitro differ considerably from the in vivo environment. This issue can be overcome by the use of intravital microscopy, which encompasses various optical microscopy techniques aimed at visualizing biological processes in live animals. Recent developments in non-linear optical microscopy resulted in an enormous increase of in vivo studies, which have addressed key biological questions in fields such as neurobiology, immunology and tumor biology. However, the motion artifacts derived from heartbeat and respiration have prevented the imaging of intracellular structures and limited the use of intravital microscopy to the analysis of tissue architecture or single cell behavior. In this respect, the goals of my thesis have been: 1) the development of an experimental system that enables visualizing subcellular organelles in live rodents for extended periods of time, and 2) the investigation of the role of the actin cytoskeleton in endocytosis and exocytosis in live rodents. Here, I describe the establishment of a model for studying endocytosis end exocytosis in the salivary glands of live rats and mice. Moreover, I show that both processes can be imaged in live animals and that their behavior and kinetics differ from what has been reported in in vitro systems. Next, I show that the salivary glands can be genetically and pharmacologically manipulated in situ, thus opening the door for the investigation of the molecular machinery regulating membrane trafficking in live animals. Finally, in the last part of my dissertation, I focus on specific approaches developed to study the kinetics of exocytosis of single secretory granules and discuss how the actin cytoskeleton plays a fundamental role in controlling this process.
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  • In Copyright
  • Weigert, Roberto
  • Randazzo, Paul
  • Bloom, Kerry
  • Rogers, Stephen
  • Duncan, Mara
  • Donaldson, Julie
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2014
Place of publication
  • Chapel Hill, NC
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