Date of Graduation

Winter 1-11-2013

Document Type


Degree Name

Master of Biological Science (MBioSci)



First Advisor

Christina Tzagarakis-Foster

Second Advisor

Jennifer Dever

Third Advisor

Scott Nunes


The orphan receptor Dax-1 is highly expressed in pluripotent embryonic stem (ES) cells and shows a correlative reduction in expression as these cells differentiate. While it is known that Dax-1 is expressed in pluripotent mouse ES cells, the precise function of Dax-1 in these cells is not as well understood. Recent studies employing RNA interference (RNAi) to specifically reduce the expression of the Dax-1 gene in mouse ES cells found that upon the knock down of Dax-1, ES cells differentiated. These findings indicate that Dax-1 functions in a novel role in the maintenance of a relatively undifferentiated state in ES cells.

Dax-1 is important in early embryonic development and, when mutated, adrenal insufficiency and disruption of normal tissue architecture results. In our study, we silenced Dax-1 expression in mouse ES cells using RNAi followed by PCR array methodology to identify genes that were alternately regulated upon targeted knock-down of Dax-1. Several novel Dax-1 targets have been identified, including genes that are involved in the Wnt signaling pathway. In attempts to understand the mechanism of Dax-1 action in ES cells, we are investigating the effect of Dax-1 knockdown on the regulation and expression of the identified target genes.