Crucially, we showed that the programmed loss of IRS-1 protein and increase in miR-126 in adipose tissue resulting from maternal diet-induced obesity is maintained in primary adipocyte precursors isolated from epididymal fat from 8-week-old offspring, which were then expanded in culture and then differentiated into adipocytes. This evidence concerns the gene IRS1 and obesity due to melanocortin 4 receptor deficiency.