In partial fulfillment of the requirements for the degree of

Doctor of Philosophy in Biology

In the

School of Biological Sciences

Kwantae Kim

Will defend his dissertation

CHORDATE-SPECIFIC GENE REGULATORY NETWORK OF NEURON DEVELOPMENT IN CIONA.

21st, November, 2023

1PM

Engineered Biosystems Building (EBB) CHOA Seminar Room (1005)

https://gatech.zoom.us/j/5210520969?pwd=UHhDVGlkVmJSMXFDK0wvQ1NSSGpHQT09

 Thesis Advisor:

Alberto Stolfi, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Committee Members:

Liang Han, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Shuyi Nie, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Farzaneh Najafi, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Christina Cota, Ph.D.

Department of Biology

Colby College

ABSTRACT: In this research, I investigated the complex gene regulatory networks underlying neurogenesis, taking advantage of the unique neurons of the Ciona model system. I revealed that Fgf signaling is crucial for the neurogenesis of Bipolar Tail Neurons (BTNs) by controlling the expression of Neurogenin, the fate-determining transcription factor in these neurons. Then I also characterized multiple effector genes functioning in the development of BTNs. Additionally, I determined the vital role of the Pax3/7 transcription factor in the neural plate border to induce the neural tube closure. Finally, I demonstrated how the Pax3/7 also orchestrates an intricate gene regulatory network upstream of multiple transcription factors and functional effectors during the neurogenesis of Descending Decussating Neurons (ddNs). I found that the majority of this network’s regulatory branches are shared with other neurons in Ciona or even other organisms including vertebrates. Moreover, I revealed the role of key putative effector genes during the neurogenesis of ddNs. These findings will provide profound insights into developmental mechanisms in the central nervous system of chordates.