Stress-induced remodeling of the caenorhabditis elegans dauer

Androwski, Rebecca Joann

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https://hdl.handle.net/2142/109469 Copy

Description

Title

Stress-induced remodeling of the caenorhabditis elegans dauer

Author(s)

Androwski, Rebecca Joann

Issue Date

2020-09-28

Director of Research (if dissertation) or Advisor (if thesis)

Schroeder, Nathan E

Doctoral Committee Chair(s)

Schroeder, Nathan E

Committee Member(s)

• Gillette, Martha
• Gillette, Rhanor
• Vidal-Gadea, Andres

Department of Study

Neuroscience Program

Discipline

Neuroscience

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• C. elegans
• dendrite
• stress
• TOR
• Insulin signaling

Abstract

Dendrite morphology is critical to the proper function of the nervous system. Stress-induced changes to the dendritic architecture of neurons has been demonstrated in numerous mammalian and invertebrate systems; however, stress-induced remodeling of dendrites varies among neuron types. During the stress-induced dauer stage of Caenorhabditis elegans, the IL2 neurons arborize to cover the anterior body wall. In contrast, the FLP neurons arborize to cover an identical receptive field in favorable conditions. How coordinated branching is established between these two neuronal subtypes is unknown. Additionally, the molecular mechanisms that underlie stress-induced dendrite morphology are poorly understood. Therefore, the goal of my dissertation is to identify effectors of IL2 dendritic morphology and determine how branching is differentially regulated between IL2 and FLP neurons. In Chapter 2, I describe the neuronal architecture of the FLPs, identify a neighborhood effect on IL2 and FLP dendrites, and characterize new alleles of branching regulators kpc-1 and dma-1. Chapter 3 shows that both the IL2s and FLPs use an identical downstream effector complex comprising of the L1CAM homolog SAX-7 to control branching. Chapter 4 compares regulation of this complex between stress-induced IL2 branching and FLP branching. Here I find a previously unknown genotype by environment interaction within the UPR, demonstrating temperature-dependent regulation of neuronal, pharyngeal, and cuticular remodeling in the dauer. In Chapter 5, I show that several aspects of the dauer formation pathway are necessary for the neuron to remodel, including the FOXO transcription factor/DAF-16, phosphatase PTEN/DAF-18 and Cytochrome P450/DAF-9. Finally, we find that the TOR associated protein, RAPTOR/DAF-15 regulates mutually exclusive branching of the IL2 and FLP dendrites. Together, our results shed light on molecular processes that regulate stress-mediated remodeling of dendrites across neuron classes.

Graduation Semester

2020-12

Type of Resource

Thesis

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http://hdl.handle.net/2142/109469

Copyright and License Information

Copyright 2020 Rebecca Androwski

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