PPARGC1A and hydrops fetalis: Finally, calculated UCP1 content for total iBAT (see Methods) and mRNA levels for the peroxisome proliferator-activated receptor γ coactivator 1-α and-β (PGC1A and PGC1B; [30]) were significant higher for HF/n-3 than for HF and control (Fig. 3d, e).