title: The fate of embryonal-carcinoma cells in mouse blastocysts.
abstract: Double-labeled embryonal-carcinoma (ECa) cells were injected into blastocysts or incorporated into blastocysts by aggregation, and their fate after various periods of time in culture was investigated. ECa-247 cells labeled with fluorescent microscopheres were easily identified in whole blastocysts. These blastocysts were embedded in plastic, serially sectioned, and prepared for autoradiography. The 3H-thymidine label on the embryonal-carcinoma cells allowed precise localization of the cancer-derived cells. ECa-247 cells preferentially localized in the mural trophectoderm, with a few being seen in primitive endoderm and, even more rarely, in the inner cell mass. Selected autoradiograms were re-embedded and thin sectioned for transmission electron microscopy. The cancer-derived cells were found to have differentiated in accordance with their localization.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology* / Q000648:ultrastructure; D002449:Cell Aggregation; D002460:Cell Line; D004261:DNA Replication; D005260:Female; D051379:Mice; D008854:Microscopy, Electron; D013724:Teratoma / Q000473:pathology* / Q000648:ultrastructure