Project description:WIN 18,446/RA treatment of neonatal mice was used to synchronize the initial wave of spermatogenesis and identify novel messages expressed within either germ or Sertoli cells as spermatogonia enter meiosis. germ cell-specific (Stra8-cre: RiboTag; or Ngn3-cre:RiboTag) and Sertoli cell-specific (Amh-Cre: RiboTag)