Date on Senior Honors Thesis


Document Type

Senior Honors Thesis



Degree Program

College of Arts and Sciences

Author's Keywords

Nucleolus; Neurites; Ribosomal proteins; Axons; RPS6; TIF-A; shRNA; B23; NPM1


Elongating axons require a host of macromolecules for outgrowth. The importance of lipid, protein, and general RNA synthesis for initial axonal growth has been previously investigated, but the role of rRNA synthesis and ribosome production in axonal morphogenesis remains unclear. Therefore, rat hippocampal neurons were cultured and transfected with shRNA against either TIF-IA (the activator of RNA polymerase I) or RPS6 (a small ribosomal subunit component) to determine the effects of impaired de novo ribosome synthesis on axonal development during the first three days after plating. Our data show that shRPS6 weakly inhibited total axon length, but not longest axon path or number of axonal branches; shTIF-IA showed no significant inhibitory effect in all three parameters. Thus, these results indicate that the pre-existing ribosome supply was at least temporarily sufficient for growth during this initial phase of axonal development.