Table 2.

Connexin expression and GJIC in iPS cells.

iPS cell lines	Connexin expression in undifferentiated cells	GJIC in undifferentiated cells	Differentiation from iPS cells	Connexin expression during differentiation	GJIC during differentiation	Methods used to determine the final phenotype of differentiated cells	References
Mouse iPS cells (O9), Mouse ES cells (E14.1)			Cardiomyocytes differentiated from iPS and ES cells with the use of a standard EB-based protocol	Cx43 in iPS cell- and ES cell-derived cardiomyocytes on day 22		Contraction, cardiac-specific gene expression, Ca2+-imaging, multielectrode array	Mauritz et al., 2008
Human iPS cells reprogrammed from primary keratinocytes	Cx432						Aasen et al., 2008
Mouse iPS cells (O9, N10), Mouse ES cells (R1, D3)			Cardiomyocytes	Cx43 in iPS cell- and ES cell-derived cardiomyocytes		Contraction, cardiac-specific gene expression, multielectrode array, electrophysiology, pharmacological reagents	Pfannkuche et al., 2009
Mouse iPS cells reprogrammed without c-MYC			In vivo 3 germ layer differentiation, i.e., endoderm, ectoderm, and mesoderm. In vitro cardiomyocyte differentiation	Cx43 in iPS cell-derived cardiomyocytes in vivo and in vitro		Contraction, cardiac-specific gene expression, Ca2+-imaging, electrophysiology, EM	Martinez-Fernandez et al., 2009
Human iPS cells reprogrammed from HUVECs	Cx431, Cx451 Not detected: Cx371	GJIC3 is re-established during reprogramming to pluripotency		HUVECs express Cx431, Cx371, and Cx451	Low GJIC in HUVECs		Sharovskaya et al., 2012
Human iPS cells reprogrammed from human embryonic fibroblasts	Cx431, 2, Cx251, Cx261, Cx301, Cx30.21, Cx30.31, Cx311, Cx31.11, Cx31.91, Cx371, Cx401, Cx451, Cx461, Cx471, Cx591, Cx621. Cx43 increases during reprogramming	Present3		Human embryonic fibroblasts express Cx431, 2 at low levels			Ke et al., 2013
Human iPS cell line (iMR90) Human ES cell lines (H7, RuES-2)			Cardiomyocytes differentiated from iPS and ES cells using a long-term (over 150 days) culture protocol	Significant increase in Cx431, 2 expression in late-stage (80–120 days) cardiomyocytes vs. early stage (20–40 days) counterparts		Optical contraction analysis, electrophysiology, Ca2+-imaging, cardiac-specific gene expression, EM	Lundy et al., 2013

¹mRNA level;

²protein level;

³dye coupling (Lucifer yellow etc.); EM, electron microscopy.