Date Thesis Awarded

5-2018

Document Type

Honors Thesis

Degree Name

Bachelors of Science (BS)

Department

Biology

Advisor

Margaret Saha

Committee Members

Alban Guillaumet

Peter Kemper

Joshua Puzey

Abstract

The high incidence of polyploidy in the Xenopus Genus suggest that there might be advantages to this phenomenon. A recent allotetraploidy event in the lineage of the model organism, Xenopus laevis, has created homeologous copies of genes that are estimated to make up ~46% of the genome. In this study, we took a global approach to study the gene expression patterns of homeologous gene copies during normal embryonic development at the mid-gastrula, mid-neurula, and late tailbud stages. Using RNA-sequencing data, we have characterized the high variance of homeolog gene expression which can be used to group homeologs into functionally distinct categories. Moreover, we have found that while there is an expression bias towards L homeologs in concordance with previous studies, expression variance is biased towards S homeologs. We further characterized homeolog expression patterns during perturbations to embryonic development at the mid-neurula, early tailbud, and late tailbud stages where we found significant changes in homeolog expression bias that may be involved in the response and compensation from these perturbations. Our results suggest that: 1) genetic redundancy might confer advantages by allowing homeologous genes to diversify in gene function which is associated with highly variable homeolog expression patterns; 2) homeologs are highly involved in the response to perturbations during development and may provide a genetic buffer which may play an important role in the compensatory process.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

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