Lola Lang

Senior Project Advisor

Suzanne Lee

Document Type


Publication Date

Spring 2024


RNA interference, Genomic maintenance, Tetrahymena thermophila, sRNA biogenesis


RNA interference (RNAi) is an evolutionarily conserved mechanism shown to have an understudied function of maintaining the genome in a wide range of eukaryotes. Recently, the Lee Lab reported that an RNAi pathway that produces ~23-24 nucleotide (nt) small (s)RNAs in the single-celled eukaryote Tetrahymena thermophila provides such genome maintenance. Critical for this role is not only the biogenesis of these sRNAs but also the RNAi machinery. In Tetrahymena, the machinery is composed of the RNA polymerase complexes (RDRCs), Dicer2, and the Piwi homolog proteins known as Twis. Additionally, RDRC-associated RNA-silencing protein 1 (Rsp1) has been shown to be crucial in synthesizing RDRC-dependent sRNAs, although how is unknown. It is believed that Rsp1 plays a crucial role for the biochemical properties of the RDRCs due to the fact a knockout of this strain showed elevated accumulation of RDRCs, yet they were unable to be purified. Previous work showed the importance of the RDRCs, Rsp1, and a specific Twi protein known as Twi8 in maintaining the genome. Knockouts of these proteins were seen to have elevated levels of Rad51, a DNA repair protein, and enlarged chromatin extrusion bodies (CEBs), akin to micronuclei in human cancer cells, although CEB data for Twi8 was not yet determined.

The focus of the work here was to further provide insight into the role of Twis in maintaining genome integrity, in addition to shedding light on how Rsp1 regulates the RDRCs.






Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.





Available for download on Sunday, July 04, 2027