Document Type


Date of Degree

Spring 2010

Degree Name

PhD (Doctor of Philosophy)

Degree In

Molecular Physiology and Biophysics

First Advisor

Davidson, Beverly L

First Committee Member

Anderson, Michael

Second Committee Member

Cornell, Robert

Third Committee Member

Johnson, Wayne

Fourth Committee Member

Russo, Andrew


MicroRNA (miRNA) function is required for normal animal development, in particular in stem cell and precursor populations. I hypothesize that miRNAs are similarly required for stem cell maintenance and appropriate fate commitment in the brain. To test the requirement for global microRNA production, I depleted the microRNA biosynthetic enzyme DICER in the developing mouse brain. I found that DICER loss in embryonic neural progenitor cells leads to embryonic lethality with microcephaly. By histological analysis, I found defects in both neural progenitor cell maintenance and cell differentiation. I also identified new candidate microRNAs for this phenotype by profiling miRNAs in DICER-depleted and control cells. Three microRNAs which are good candidates to modulate nervous differentiation are miR-23b, -182, and -34a. I describe the expression pattern and functional characterization of these candidates. In particular, miR-34a depletes neuron production after progenitor cell differentiation in culture, likely by modulating cell cycling and Notch pathway genes.


corticogenesis, Dicer, differentiation, microRNA, neural progenitor cell, Notch


xii, 141 pages


Includes bibliographical references (pages 130-141).


Copyright 2010 Sarah Kathryn Fineberg

Included in

Biophysics Commons