The undifferentiated spermatogonial population of mouse testis is known to be functionally heterogeneous and contain both stem cells and committed progenitor cells. However, gene expression patterns marking these distinct cell fractions are poorly defined. We found that a subset of undifferentiated spermatogonia were marked by expression of a PDX1-GFP transgene but properties of these cells were unclear. Undifferentiated cells were therefore isolated from adult testes and separated according to expression of PDX1-GFP+ for gene expression analysis by RNA-seq. Our goal was to identify differentially expressed genes from PDX1-GFP+ vs PDX1-GFP- with that of known markers of stem and committed progenitor cells. Overall design: 4 independent sets of PDX1-GFP-positive and PDX1-GFP-negative undifferentiated spermatogonia were isolated by flow sorting from adult mouse testes.