Coupling organelle inheritance with mitosis to balance growth and differentiation

Peroxisome inheritance and differentiation For normal tissue structure and function, cells exert strict control over growth versus differentiation. Poor wound healing and aging can result from too little proliferation. Conversely, the development of cancer can involve excessive cell growth. Asare et al. looked for regulators that balance proliferation and differentiation in the epidermis (see the Perspective by Gruneberg and Barr). They observed differences in the transcript profile of epidermal progenitors, their differentiating progeny, and epidermal cancers. Epidermal progenitors that were deficient in the peroxisome-associate protein Pex11b did not segregate peroxisomes properly among dividing cells. This led to a delay in mitosis that perturbed polarized divisions. These events skewed daughter cell fate and resulted in a defective skin barrier. Thus, peroxisome inheritance appears to play a role in normal mitosis and cell differentiation. Science , this issue 10.1126/science.aah4701 ; see also p. 459