Date of Award

Spring 5-21-2022

Document Type

Thesis

Degree Name

Bachelor of Arts

Department

Biology

First Advisor

Karen A. Hicks

Second Advisor

Wade H. Powell

Abstract

For many organisms, biological fitness depends on appropriate timing of reproduction. Reproductive development in plants is largely regulated in response to environmental changes like day length and temperature. Our research probes the evolutionary origin of this mechanism in land plant divergence. Specifically, we seek to understand whether sexual reproduction is regulated in the same way in angiosperms and bryophytes, suggesting conservation of an ancient mechanism. We have identified a small set of differentially expressed COP1-related genes predicted to be involved in seasonal regulation in P. patens (V. Coneva and K. A. Hicks, unpublished results). We then designed single guide RNAs and employed the CRISPR-Cas9 system to knock out several COP1-like genes of interest, and assessed the effects of deleterious frameshift mutations on reproductive timing. Ppcop1h/i mutants initiated reproduction at the same time as wild type, but the sporophytes developed more quickly. The lack of a clear phenotype motivated us to work on three additional PpCOP1 genes, for which we have generated various types of mutants, again via CRISPR-Cas9. Future analysis of these knockout individuals will pave the way for a more complete understanding of the COP1 pathway in P. patens and its evolution in land plants.

Rights Statement

All rights reserved. This copy is provided to the Kenyon Community solely for individual academic use. For any other use, please contact the copyright holder for permission.

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