POLG and hydrops fetalis: The increasing effects on HF seen in the Polg+/+Tfam+/− and Polg+/+Bcl2l13−/− animals and the decreasing effect on HF observed in the Polg+/+Ulk2−/− group were reflected in the HF distribution (Fig. 4B), demonstrating that reduction of TFAM expression and disruption of BCL2L13 and ULK2 expression modulate the HF.