Adipose tissue is found in depots at distinct locations throughout the body. While two main types of adipose tissue – white and brown - are known to exist and perform different functions, the developmental origins of these distinct depots are unclear. Here, Matthew Rodeheffer and colleagues set out to clarify the ontogeny of major adipose depots in mice. They use a number of constitutive and inducible Cre/Lox systems to track the fate of cells within subcompartments of the mesoderm, the germ layer from which adipose cells (adipocytes) are proposed to arise. Using this approach, they first show that, in contrast to previous reports, the central dermomyotome contributes to only a subpopulation of interscapular white and brown adipocytes. However, this compartment does contribute to a major proportion of the perigonadal lineage in males, but not in females. The researchers further report that the posterior lateral plate mesoderm contributes to both subcutaneous and visceral adipocyte lineages, suggesting that these depot-specific lineages have a common origin but segregate during late embryogenesis. Finally, they report that adipocyte precursors of different origins within the same depot exhibit indistinguishable responses to a high fat diet, highlighting that depot microenvironment rather than developmental history is a key regulator of adipocyte precursor function.
