Panel A, Fluorescence profile of all cells isolated from the metrial gland. Panel B, Fluorescence profile of an aliquot of GFP negative cells; Panel C, Fluorescence profile of an aliquot of GFP positive cells; Panel D, cytokeratin immunostaining of GFP positive cells. Panel E, RT-PCR analysis of Prl7b1, Ascl2, Gcm1, and 18S ribosomal RNA in EGFP positive cells. Abbreviations; MG, metrial gland; LZ, labryrinth zone; JZ, junctional zone; IT, isolated invasive trophoblast. Panel F, Ploidy analysis of EGFP positive invasive trophoblast cells. Panel f-1, total metrial gland cells sorted by fluorescence; panel f-2, spleen cells stained with propidium iodide and analyzed for DNA content; panel f-3, EGFP positive invasive trophoblast cells stained with propidium iodide and analyzed for DNA content.