PDGFRA and obesity due to melanocortin 4 receptor deficiency: To examine if deletion of Mgp in Pdgfra-expressing progenitors affects diet-induced obesity in adult mice, we treated male and female Pd–KO and F/F control mice for 20 weeks with chow diet (CD) or high-fat diet (HFD; 45 kcal% fat) starting at 8 weeks of age (Figure 5A for timeline).