Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Biological Sciences (MS)

Administrative Home Department

Department of Biological Sciences

Advisor 1

Paul Goetsch

Committee Member 1

Xiaohu Tang

Committee Member 2

Zhiying Shan


The highly conserved Dp, Rb, E2F, and MuvB (DREAM) complex is responsible for the transcriptional repression of cell cycle genes. The DREAM complex has been extensively studied in somatic (non-reproductive) cells, but there is a gap in knowledge regarding how the DREAM complex may function in germ (reproductive) cells. To demonstrate loss-of-function of DREAM in the germline, we used the auxin-inducible degron (AID) system to establish degradation of LIN-54, a subunit of DREAM’s MuvB subcomplex, and the Retinoblastoma-like pocket protein LIN-35 in C. elegans. Using transgenic lines that express the Arabidopsis thaliana TIR1 E3 ubiquitin ligase ubiquitously through all C. elegans tissues or specifically only in somatic tissue, we evaluated the effects following treatment of auxin that triggers TIR1-mediated rapid degradation of degron-tagged LIN-54 or degron-tagged LIN-35. In our LIN-54 evaluation, brood size counting experiments showed a difference in fertility between worms exposed to auxin and the control group in both TIR1 transgenic lines, suggesting either that LIN-54’s somatic activity is important for fertility or the somatic-expressed TIR1 transgene had some activity in the germline. Subsequent fluorescence microscopy revealed decreased expression of LIN-54 or LIN-35 in the germline in each TIR1-expressing transgenic worm background when exposed to auxin, as compared to the control group, indicating that the somatically-expressed TIR1 transgene does have activity in the germline. These results suggest that DREAM disruption in the germline negatively affects germ cell production and fertility. Our results underscore that new TIR1-expressing transgenic lines will have to be generated to confirm that DREAM’s somatic activity does not contribute to fertility in some form.

Creative Commons License

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