Fig. 2. Neural stem cells can generate skeletal and cardiac myocytes. In order to demonstrate the potential of NSCs, CD31^- CD35^- EGFP⁺ cortical progenitor cells were expanded for 6 days in MB-media prior to plating on an adherent surface to complete differentiation. By both reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical analyses, differentiated progeny expressed markers of myogenic differentiation. (A) RT-PCR was performed to assess the steady state levels of MyoD expression of skeletal muscle actin and cardiac actin mRNAs at 7 and 18 days of MLNSC differentiation. A photomicrograph of an ethidium bromide stained agarose gel displaying the amplification products for reactions using mRNA isolated from cultures at day 7 and day 18 of differentiation is shown. (B-D) Time course of sk-MHC immunoreactivity within differentiating clones 9 days (B), 11 days (C) and 18 days (D) post-plating is presented. (E) Immunofluorescent images for cardiac-specific MHC and the gap junction protein, Cnx43, immunoreactivity at day 18 after plating. NSCs gave rise to cardiac myocyte immunoreactive progeny. Scale bar: 150 µm.