Item Details

abstract

Nearly all genomes contain mobile DNA elements that move from one location to another via transposition. The movement of these elements can cause mutation, either because the element inserts within a gene or because it promotes significant mutations via recombination between pairs of mobile elements in different locations, etc., the most common of which are chromosomal rearrangements. These chromosomal mutations (such as insertions, deletions, or translocations) cause changes in gene expression and copy numbers of genes and are more likely to occur through transposition than through a single nucleotide change from a random base-pair mutation. Chromosomal mutations impact the entire chromosome, and the structural changes that occur can often be deleterious. However, these types of mutations can also be essential for populations because they often lead to adaptive evolution and an increase in genetic diversity. This research sought to determine the role of transposable elements on genome evolution and on adaptation to novel selective pressures by introducing a highly active foreign transposable element, Hermes, to a host population of Saccharomyces cerevisiae yeast. It was determined that invasion by the transposon required outcrossing sex and did not occur in initially identical asexual populations maintained within the same environment. Furthermore, invasion and establishment of the transposon increased evolvability through novel adaptive mutations when grown in a lethally hyperosmotic environment and modified the expression levels of several key stress-associated genes. The advantages afforded to host populations harboring the novel Hermes transposon may give insight into the benefits of sexual reproduction in eukaryotic organisms and why this type of reproduction is so widespread.

subject

evolution

genome

population

transposable element

yeast

contributor

Shultz, Ashley Lynne (author)

Zeyl, Clifford F (committee chair)

Tague, Brian W (committee member)

Curran, James F (committee member)

Zhang-Reid, Ke (committee member)

date

2022-09-17T08:35:41Z (accessioned)

2022 (issued)

degree

Biology (discipline)

2023-03-16 (liftdate)

embargo

2023-03-16 (terms)

identifier

http://hdl.handle.net/10339/101249 (uri)

language

en (iso)

publisher

Wake Forest University

title

THE EVOLUTIONARY EFFECTS OF INVASION OF S. CEREVISIAE POPULATIONS BY THE FOREIGN TRANSPOSABLE ELEMENT, HERMES

type

Dissertation