Table 1.

Cardiac and skeletal muscle-specific Cre lines

Tissue specificity	Cre line	Expression Temporal	Expression Spatial	Efficiency	Laboratory source	Original reference	Potential caveats
Cardiac  constitutive	Alpha MHC	E10.5	CMs	70% excision in  adult CMs	Abel	[34]	-
	Alpha MHC	Low levels E8.0–E10.0	CMs	70–80% excision  by 3 weeks	Schneider	[35]	High expression level  leads to DCM
	Beta MHC	E12.5	CMs	70% excision by   E17.5	Yutzey and  Molkentin	[66]	Expressed in somites  and soleus muscle
	Nkx2.5	E8.0-E8.5	CMs	88% excision in  adult CMs	Olson	[37]	-
	Nkx2.5	E7.75–E8.0	CMs, pharyngeal  endoderm	High	Harvey	[38]	-
	Nkx2.5	E7.5	CMs	100% excision by  PI	Schwarz	[39]	Development of heart  abnormalities
	cTnT	E7.5–E10.5	CMs	High	Hogun	[42]	Breeding problems in  older mice
	XMLC2	E7.5–  adulthood	CMs	High	Mohun	[44]	-
	MLC2v	E8.5	Ventricular CMs	Low	Chen	[45]	-
Inducible  cardiac	MerCreMer-Alpha   MHC	N/A	CMs	>80% excision   after 5 days	Molkentin	[48]	Cre toxicity observed at   high levels
	MerCreMer-cTnT	N/A	CMs	High	Cai	[55]	-
	Tet-TnT	N/A	CMs	Not reported	Zhou	[56]	-
Constitutive  skeletal	HSA	E9.5	Skeletal muscle, some  evidence in heart	High	Melki	[57]	Low level expression in  the heart
	Myo	E8.5	Skeletal muscle lineage	>90% excision	Olson	[60]	-
Inducible  skeletal	HSA-MerCreMer	-	Skeletal muscle, some  evidence in heart	High	Esser	[58]	Low level expression in  the heart
	HSA-Tet	-	Skeletal muscle	Not reported	Monks	[59]	-
	CreRT2 lines	-	Various		Lepper	[61]	-

CMs: cardiomyocytes, E: embryonic day, MHC: myosin heavy chain, Nkx2.5: Nk2 homeobox 5, cTnT: cardiac troponin T, XMLC2: Xenopus myosin light chain 2, MLC2V: myosin light chain 2 ventricular, MerCreMer: mutated estrogen receptor, Dox: doxycycline, HSA: human alpha skeletal actin, DCM: dilated cardiomyopathy