Pluripotent Embryonal Stem Cell Lines Can Be Established from Disaggregated Mouse Morulae

Abstract

Mouse pluripotent embryonal stem (ES) cell lines hitherto have been conventionally isolated from the ''inner cell mass'' of mouse blastocysts. In this report, I describe a new and simplified method for establishing pluripotent cell lines from mouse morulae of the 16- to 20-cell stage, which were disaggregated by the use of EDTA. From 17 cell lines established in such a way, 7 were characterized with respect to their differentiation potential: (i) When injected into syngeneic mice, the cells gave rise to solid, fully differentiated teratomas representing derivatives of all three germ layers. (ii) When cultured in suspension in vitro, the cells were able to differentiate into complex organized ''embryoid bodies'' analogous to mouse early postimplantation embryos. These results strongly imply that embryonal stem cell lines isolated from mouse morulae are highly homologous to conventionally isolated ES cells. In addition, my results indicate that murine pluripotent embryonal stem (ES) cell lines can be derived with more ease and higher efficiency from disaggregated morulae than from the ''inner cell mass'' of blastocysts.