Date of Award

6-1-2014

Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biology/Molecular, Cellular, and Organismal Biology

First Advisor

Adán Colón-Carmona

Second Advisor

Kenneth C. Kleene

Third Advisor

Alexey Veraksa

Abstract

In mitosis, when chromosome attachment errors are detected, a surveillance mechanism called the spindle assembly checkpoint (SAC) delays the transition from metaphase to anaphase. When all chromosomes are accurately anchored to spindle microtubules and have migrated to the cell equator, the checkpoint is released and mitosis proceeds. Centromere-associated protein-E (CENP-E) is a motor protein from the kinesin-7 family thought to be an important contributor of the SAC. In plants, most mitotic and meiotic SAC components and processes are unknown.

Using a reverse genetics approach, I present cytological evidence that ATCENPE2 is a conserved gene of the plant mitotic checkpoint and is an important regulator of meiosis. I show that an insertion mutation, atcenpe2-1, prevents the normal alignment of chromosomes, causing a delay in mitosis. Aneuploidy is also observed in some cells, indicating an altered checkpoint function. Significantly, the atcenpe2-1 mutant shows problems in chromosome segregation during meiosis, causing gamete malformation. Together, these data describe the novel role of a previously uncharacterized kinesin in plant mitosis and meiosis. Furthermore, this study offers an important tool to study the consequences of aneuploidy at a cellular and organismal level.

Comments

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Supplemental Movie 1 -- Described on page 74 of dissertation

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Supplemental Movie 2 -- Described on page 74 of dissertation

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Supplemental Movie 3 -- Described on page 74 of dissertation

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Supplemental Movie 4 -- Described on page 74 of dissertation

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Supplemental Movie 5 -- Described on page 74 of dissertation

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Supplemental Movie 6 -- Described on page 74 of dissertation

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