Physical basis of the cell size scaling laws.

Cellular growth is the result of passive physical constraints and active biological processes. Their interplay leads to the appearance of robust and ubiquitous scaling laws relating linearly cell size, dry mass, and nuclear size. Despite accumulating experimental evidence, their origin is still unclear.

Nuclear fragility, blaming the blebs.

Although textbook pictures depict the cell nucleus as a simple ovoid object, it is now clear that it adopts a large variety of shapes in tissues. When cells deform, because of cell crowding or migration through dense matrices, the nucleus is subjected to large constraints that alter its shape. In this review, we discuss recent studies related to nuclear fragility, focusing on the surprising finding that the nuclear envelope can form blebs.