The molecular mechanisms regulating germ cell development and potential. 
Time-critical extracellular stimuli as well as the intrinsic functions of transcriptional regulatory molecules play essential roles in fate determination and differentiation of mouse primordial germ cells (PGCs).  We found that the precursor cells of PGCs require E-cadherin-mediated cell-cell interaction and the functions of transcription factor Oct3/4 to be specified to PGCs.  In addition, transcriptional factors commonly regulating a number of PGC-specific genes appear important for PGC development, and we demonstrated that PGC-specific expression of the mil-1 gene is controlled by germ cell-conserved regulatory sequences in the 5' flanking region.  Once they have undergone specification and differentiation, PGCs normally give rise to gametes, but they maintain the potential to be converted into pluripotential stem cells upon activation of particular signaling pathways.