FIG. 2.

Characterization of Rag2 ES–somatic cell hybrids. (A) Rag2 gene expression in undifferentiated cells and following 14 days of EB formation and differentiation. (B) Teratoma formation of hybrid cells in 129SvEv×C57BL/6 autologous mice. (C) Histology of teratoma tissue showing (i) secretory epithelium, (ii) neural rosettes, and (iii) articular cartilage. (D) Immunohistochemical analysis of teratoma sections revealed positive staining for the lineage germ-line markers for (i) endoderm (mucin), (ii) ectoderm (cytokeratin 6, CK6), and (iii) mesoderm (SMA). (E) Karyotype analysis of Rag 2 Hyb C showing an expected tetraploid karyotype of 80 chromosomes. (F) FACS ploidy analysis of hybrid cells recovered from teratomas (blue), overlaid with diploid ESC controls (red) stained with Propidium Iodide. Color images available online at www.liebertpub.com/cell