Figure 2. Brite adipocyte formation from white adipocytes. Two potential models of how mature apparently white adipocytes can be transformed into brite adipocytes are depicted. A potential contribution of any precursor cells to brite adipocyte recruitment is not taken into account here. Left: Adipocyte precursors within a white adipose tissue depot develop into a homogenous population of mature white adipocytes. Upon cold adaptation, a subset of these transdifferentiates into thermogenic brite adipocytes. The subset could be determined by their vicinity to blood vessels and thus circulating factors, adrenergic nerve endings or special extracellular matrix components. Right: Different subsets of the adipocyte precursor population within a white adipose tissue depot develop into an apparently homogeneous but intrinsically heterogeneous population of cells with mature white adipocyte characteristics. One subset of these cells holds the potential to transform into thermogenic brite adipocytes upon cold adaptation, while the others remain white adipocytes.