Date of Defense


Date of Graduation



Biological Sciences

First Advisor

Pamela Hoppe

Second Advisor

Todd Barkman


This research investigates the unexpected significance of Myosin A in the organization of M-line protein UNC-89/obscurin within striated muscle cells of the nematode Caenorhabditis elegans (C. elegans). The study employs immunofluorescence techniques to examine the spatial and temporal dynamics of UNC-89/obscurin and Myosin A during embryonic development. The sarcomere, a fundamental unit in muscle cells, is governed by the 'sliding filament model,' where the M-line serves as a crucial anchor for Myosin A. This research seeks to understand the relationship between muscle function in humans and C. elegans, utilizing the latter's simple anatomy and genetic tractability. The investigation focuses on UNC-89, a protein analogous to human obscurin, and its unexpected dependence on Myosin A for proper localization and organization. The study involves two main aspects: first, examining the impact of UNC-89/obscurin on Myosin A organization in unc-89 mutant embryos, and second, elucidating the role of Myosin A in UNC-89/obscurin organization in pat-10 mutant embryos. Unexpectedly, UNC-89 appears to rely on Myosin A during later stages of embryonic development, emphasizing a dynamic relationship between these proteins. The experimental approach includes antibody staining of embryos, confocal microscopy, and comparative analysis of staining patterns in wild-type and mutant embryos. Results reveal distinct staining patterns in unc-89 mutants at the 3-fold stage, suggesting a crucial role for UNC-89/obscurin in Myosin A organization during this developmental phase. In contrast, pat-10 mutants, despite lacking muscle contraction and body elongation, exhibit organized UNC-89/obscurin and Myosin A, highlighting the unique contribution of Myosin A to UNC-89 organization. This research contributes valuable insights into the molecular mechanisms governing muscle organization in C. elegans, emphasizing the significance of UNC-89/obscurin and Myosin A interdependence. The findings open more possibilities for further exploration of the genetic and molecular pathways influencing muscle development and may have implications for understanding muscle-related conditions in humans.

Access Setting

Honors Thesis-Open Access

Included in

Biology Commons