Date of Award

2011

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

Abstract

Long terminal repeat (LTR) retroelements are mobile DNAs that are ubiquitous in eukaryotic genomes and include retroviruses, endogenous retroviruses and retrotransposons. Though retrotransposons, which are noninfectious, can make up as much as 80% of plant genomes, no traces of retroviral elements have been confirmed in plants. However, the 2000-copy soybean retrotransposon SIRE1 has an extra open reading frame, that has been described as env-like, because its conceptual translation product is predicted to have features of retroviral envelope proteins, which sponsor infectivity. Demonstrating that this region encodes an envelope protein would extend the range of endogenous retroviruses to plants. Demonstrating also that the env-like protein is produced in vivo suggests that the putative plant endogenous retroviruses are actively produced and might retain the ability to infect. This project lays the foundation for determining if SIRE1 is an active (and possibly infectious) plant endogenous retrovirus by finding evidence of env-like production in soybean. Though env-like RNA has been detected, retroelement transcription is not always indicative of translation. Therefore, polyclonal antibodies were generated against a translation product of the SIRE1 env-like gene cloned in E. coli to directly detect the protein in soybean tissue under conditions known to induce the expression of related plant elements. My results provide preliminary evidence of SIRE1 env-like protein production, suggesting that SIRE1 may be an active endogenous retrovirus and possibly an infectious plant retrovirus.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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