Graduation Term

Summer 2026

Degree Name

Master of Science (MS)

Department

School of Biological Sciences

Committee Chair

Tom Hammond

Committee Member

Kevin Edwards

Committee Member

Viktor Kirik

Abstract

Neurospora Spore killer-3 (Sk-3) is a complex meiotic drive elements (MDEs) that distorts Mendelian inheritance by selectively killing spores that do not inherit the element. The meiotic drive mechanism is thought to require synthesis of a poison and an antidote. While the gene encoding the antidote has been discovered, the location of the poison gene remains unresolved. Locating the poison gene is complicated by the length of Sk-3, which spans 3 Mb and contains several hundred genes. Preliminary research has identified an interval called i350 that seems to be crucial for killing. Here, I employed a targeted deletion and transformation technique to investigate the i350 interval. I also examined if a known spore-killing-disruption mutation, referred to as rfk-2UV is allelic with the i350 interval. Finally, I transferred the i350+ interval to a non Sk-3 strain to see if it could confer spore killing ability in a non-Sk-3 genetic background. My results demonstrate that i350+ encodes a poison gene required for spore killing and that rfk-2UV and i350 are allelic. Furthermore, while i350+ did not provide the ability to kill spores to a non-Sk-3 strain, it did rescue spore killing to Sk-3 strains that were unable to kill spores due to mutation at the native i350 locus. These results suggest that production of the Sk-3 poison requires at least two genes, one encoded within i350 and a second present at an unknown location within the Sk-3 genetic element.

Access Type

Thesis-Open Access

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