Defense Date

2014

Document Type

Thesis

Degree Name

Master of Science

Department

Biochemistry

First Advisor

Young You

Abstract

Marfan Syndrome (MFS) is one of the most common monogenic diseases and affects approximately 1 in 5,000 individuals worldwide. The syndrome is characterized by elongated extremities, tall stature, slender frame, and cardiac, and vision abnormalities due to severe connective tissue defects. It is caused by mutations in the fbn1 gene, which encodes an extracellular matrix glycoprotein, and is required for proper cardiac and skeletal development and for sequestration of TGFβ (transforming growth factor beta) and BMP (bone morphogenetic protein) within the extracellular matrix (ECM). The primary objective of this study was to establish a C.elegans MFS model and use this model to determine which genes interact with a C.elegans fbn1 homolog, MUA-3 and ascertain the role of metabolic rate in the development of MFS pathology. We isolated a temperature sensitive mutant of mua-3, a fbn1 homolog. We found that at the fourth larval molt, when animals shed the exoskeleton and rebuild a new one, the mutants die due to extensive mechanical stress in connective tissue shown as fragmented internal structures. Using this mutant, an unbiased forward genetic screen to isolate the genetic interactors of the fibrillin gene homolog, was completed. A collagen gene, that has been implicated to genetically interact with a bone morphogenetic protein (BMP), was isolated. This suggests that mua-3(uy19) may interact with genes involved in TGFβ regulation during the L4 molt and that fibrillin-1, TGF-β, and metalloproteases may act in-concert to modulate TGFβ availability and connective tissue integrity in C. elegans. In addition, we found that two independent mutations of mua-3 show temperature-sensitive phenotypes. Based on this result, we propose that increase of temperature aggravates the phenotype potentially due to increased metabolism. This hypothesis, if correct, will suggest a potential connection between metabolic rate and severity of MFS pathology.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-15-2014

Available for download on Wednesday, May 15, 2019

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