Figure 2. K_ATP overexpression causes in utero heart failure and embryonic lethality.

(A) Littermate 9.5 dpc WT (left) and DTG (right) embryos. DTG embryo demonstrates growth retardation. (B) 10.5 dpc WT (left) and DTG (middle) embryos. DTG embryo demonstrates growth retardation, pericardial effusion and diffuse hydrops. Dark field imaging (right) demonstrates that the 10.5 dpc DTG heart is arrested developmentally at the primitive loop stage (9.5dpc). (C) Two dimensional ultrasound image of a 9.5 dpc live DTG embryo with a normally beating heart. The head is marked with a green arrow. The heart is marked with a red arrow. The embryonic sac is marked with a red circle. The red/yellow line represents the M mode plane across the embryo’s heart. The lower M mode panel demonstrates systole (S) and diastole (D). Sizing scale (for C–E) indicates 0.1 mm. Timing bar (red) in lower panel indicates 200 msec. (D) Two dimensional ultrasound of a 9.5 dpc DTG embryo, a littermate of the embryo in C, demonstrating an empty sac with an absorbed embryo. (E) Two dimensional ultrasound image of a 10.5 dpc WT embryo with normal development. (F) Two dimensional ultrasound of a 10.5 dpc DTG embryo demonstrating growth retarded embryo with pericardial effusion. (G) Summary of fetal heart rates (BPM=beats per minute) in live embryos demonstrates no statistical difference between the different genotype groups.