Honors Theses

Date of Award

Spring 4-30-2021

Document Type

Undergraduate Thesis



First Advisor

Joshua Bloomekatz

Second Advisor

Rebecca Symula

Third Advisor

Mika Jekabsons

Relational Format



Congenital heart defects (CHDs) are one of the most prevalent types of birth defects in the United States. Both environmental and genetic components are known to contribute to the development of CHDs. One of the ways toxins present in the environment cause CHDs is by disrupting the expression of genes known to be vital in normal cardiac morphogenesis. Thus, the identification of both toxins that cause birth defects in cardiac development and genes expressed during heart development is crucial in order to fully understand the relationship between environment and genetics as they relate to CHD. Due to their external development, high fecundity, and knowledge of their genome sequence, zebrafish are an excellent model organism in which to study both gene expression and the role of toxins in cardiac development. Further, many zebrafish genes are orthologous to those found in humans, and thus allow genetic findings in zebrafish to be extrapolated to research on human disease and physiology. In order to identify genes expressed in the heart during development a single-cell RNA sequencing (scRNAseq) study was performed by the Bloomekatz laboratory, which preliminarily identified a novel gene ccdc141 (coiled-coil domain containing 141) as having a role in cardiac development and possibly CHDs. Here, we have sought to validate these preliminary studies by determining the spatial and temporal gene expression of ccdc141 throughout the early stages of zebrafish development. In situ hybridization (ISH) procedures utilized for this purpose are ideal for visualizing gene expression as the entire organism can be viewed at once. Our hypothesis is that ccdc141 will be expressed in the heart of developing zebrafish. Results obtained through ISH show that ccdc141 is expressed in the heart and in cardiac precursors, as well as in somites and the head. These data will aid in further studies to determine the function of ccdc141 in development. In addition to our work on identifying the gene expression of ccdc141, we created an extensive table of environmental toxins that disrupt cardiac development in zebrafish and may contribute to the pathogenesis of CHD in humans.

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Creative Commons Attribution 4.0 International License
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