Electronic Thesis and Dissertation Repository


Master of Science


Developmental Biology


Thomas Drysdale


Congenital heart defects (CHDs) are associated with a number of genetic and environmental risk factors affecting approximately 1% of newborns. Shroom3 is an actin binding and microtubule organizing protein essential for neural tube closure in mouse, Xenopus and chick. In Xenopus shroom3 expression is found within the forming heart and loss of activity results in malformed hearts. In addition, SHROOM3 has recently been associated with heterotaxy in a human patient. Mice homozygous for the Shroom3 gene trap die at birth due to exencephaly and here, I provide evidence that the majority of these mice have CHDs, including septal defects, semilunar valve abnormalities, decreased ventricle wall thickness and functional deficits. I fully describe the expression pattern of Shroom3 in heart development, demonstrating it is widely expressed throughout the myocardium. My study is an initial step in characterizing the cell activities that drive cardiac morphogenesis and that result in CHDs when disrupted.