FIG. 3.
Failure of in vitro cellular differentiation in the absence of CGBP. (A) Colony morphology following induction of differentiation. Embryoid body outgrowths carrying the indicated CGBP alleles were cultured for 5 days in the absence of LIF. Magnification, ×20. (B) ES cells grown in the absence of LIF for 10 days were harvested, disaggregated, reseeded, and stained for alkaline phosphatase activity. One hundred cells of each genotype were scored for staining. Magnification, ×64. (C) ES cells carrying the indicated CGBP alleles were cultured for various times (0, 5, or 10 days) in the absence of LIF to induce differentiation. Total RNA was isolated, and reverse transcription-PCR was performed to examine the expression of lineage and development-specific gene markers. Oct4, marker of undifferentiated ES cells; Brachyury, mesoderm; MHC-β, muscle; c-fms, myeloid; gp-IIB, megakaryocyte; GATA-4, endoderm; HPRT, control for RNA quantity and integrity.