View Program - 63rd Annual Drosophila Research Conference

Transcription is a dynamic process during development. Much of our understanding of transcription comes from studies of snapshots of individual timepoints. Live imaging approaches based on MS2-MCP technologies have provided numerous insights into transcriptional dynamics during embryonic development, yet we still know very little about how these dynamics affect later developmental processes. Studying transcriptional bursting in genes that regulate development, such as spineless (ss) in D. melanogaster, can reveal the role of transcriptional dynamics in the production and regulation of specialized appendages and organ systems. ss is differentially expressed in the eye, antenna, and leg to promote differentiation. In the antenna, ss is consistently expressed, whereas in the eye, ss is variably expressed. My studies focus on ss expression in the leg, where it turns off in one region and turns on in a different region during development. To establish when ss turns off in the central region and later turns on in the anterior region of the leg imaginal disc, I conducted RNA FISH on wild-type flies at several timepoints between 90-120 hours after egg-laying. Next, I will utilize the MS2-MCP system to track transcription in real-time in the developing fly leg. Based on these data, I will generate a transcriptional bursting model, which creates a visualization of multiple bursts of transcripts over time. This model will shed light on how single molecules of RNA polymerase, transcription factors, and cofactors regulate gene activity at the single-gene level. By assessing the bursting patterns of ss in the legs and comparing it to the antenna/eye, I will determine how the transcriptional dynamics of a single gene can impact its regulation of cell fate determination in different contexts.

Defining the Dynamics of Transcriptional Bursting in Developing Drosophila legs

**Defining the Dynamics of Transcriptional Bursting in Developing Drosophila legs**