Date of Defense

4-16-2019

Date of Graduation

4-2019

Department

Biological Sciences

First Advisor

Donald Kane

Second Advisor

Rachel Warga

Third Advisor

Pamela Hoppe

Abstract

The cell cycle is the fundamental process every cell undergoes in order for it to divide from one cell into two. While seemingly simple, the cell cycle’s complexity allows for mishaps to occur at different checkpoints leading to mutations or cell death. This study aimed to characterize the speed bump mutant of zebrafish. The speed bump mutant is due to a nonsense mutation in the gene for the Wee1 Kinase. The Wee1 Kinase inhibits the Mitosis Promoting Factor (MPF) to ensure that cells do not enter mitosis too early. Once cells have stopped dividing and begun to differentiate into specific tissues and organs, however, it is hypothesized that Wee1 Kinase is no longer necessary. This study aimed to test this hypothesis by asking how many cells were in mitosis within a differentiated tissue, the hatching gland, of zebrafish embryos. The hatching gland normally stops dividing in the zebrafish embryo shortly after the onset of gastrulation. This study also asked when the wee1 gene is mutated whether there is an effect when the embryo was heterozygous for the nonsense allele. It was observed that at the younger stages of development there were a large number of cells in mitosis in the hatching gland of mutants when, in the wild-type embryos there were almost none. By the 19-somite stage, the number of cells in mitosis in mutants was equivalent to wild type. These results indicate that the Wee1 Kinase may play an important role in keeping cells from dividing once they have begun to differentiate and that, in its absence, cells divide inappropriately. There also did not appear to be a heterozygous effect. The information gathered from this study will allow for a better understanding of the role of Wee1 Kinase during development and differentiation.

Access Setting

Honors Thesis-Restricted

Restricted to Campus until

6-18-2021

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