Honors Theses

Date of Award

Spring 5-9-2020

Document Type

Undergraduate Thesis



First Advisor

Joshua Bloomekatz

Second Advisor

Jennifer Meyer

Third Advisor

Mika Jekabsons

Relational Format



Congenital heart defects (CHDs) are currently the most prevalent form of birth defect in the United States. Their combined frequency and severity make necessary a deeper understanding of the molecular underpinnings guiding heart formation. The first major step in cardiac morphogenesis, cardiac fusion, involves the medial movement of bilateral populations of myocardial precursor cells to the embryonic midline, where they merge to form the primitive heart tube. Although crucial to subsequent organogenesis, the precise mechanisms governing cardiac fusion remain unknown. Previous studies have found that a mutation in platelet-derived growth factor receptor alpha (pdgfra), called refuse-to-fuse (ref), results in a lack of proper cardiac fusion in both mouse and zebrafish, implying a regulatory role for pdgfra in cardiac fusion. However, the specific tissue that pdgfra functions within (myocardium, endocardium, or endoderm) remains unknown. This study details the creation of two transgenic constructs by means of the Gateway multi-site recombination system, Tg(Bact:loxp-BFP-loxp-Ra-2a-mcherry) and Tg(Nkx2.5:Cre-pA) for the purpose of elucidating the functional location of pdgfra during cardiac fusion. These constructs will allow pdgfra to be expressed in either the myocardium, endocardium, or endoderm, in mutant ref embryos. Thus, allowing us to test whether pdgfra expression in the myocardium, endocardium, or endoderm, can rescue the ref mutant phenotype. In addition to work identifying the functional location of pdgfra, another project undertaken during my time in the Bloomekatz lab involved the creation of a review chapter, covering the use of zebrafish as a model organism to study CHDs. In this endeavor three figures were created, depicting the molecular contractile mechanisms in a sarcomere, an example of zebrafish being used to model a genetic disease involving the gene titin (ttn), and the physiological similarities shared between humans and zebrafish. The review chapter has been accepted and is pending publication. Lastly, my work in the Bloomekatz lab involved multiple 3D printing projects to create confocal microscope slide holders, a feeding gun apparatus, and gel electrophoresis combs.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.



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