The Company of Biologists

Table 1.

Total number of embryos or neonates observed

Stage	Number ofα _c-actin^+/nlaacZ1.1embryos or neonates	Number of β-gal-positive hearts(%^{^*})
E8.5	1488	112^{^†}(7.5%)
E10.5	641	430 (67%)
E14.5	627	595 (95%)
P7	316	316 (100%)

Stage	Number ofα _c-actin^+/nlaacZ1.1embryos or neonates	Number of β-gal-positive hearts(%^{^*})
E8.5	1488	112^{^†}(7.5%)
E10.5	641	430 (67%)
E14.5	627	595 (95%)
P7	316	316 (100%)

% is the number of β-gal-positive hearts divided by the number ofα _c-actin^+/nlaacZ1.1embryos or neonates.

Ninety-two hearts from embryos with 9-17 somites are analysed here.