Abstract:
Cell-fate specification is typically thought to precede and determine cell-cycle regulation during differentiation. Here we
show that endoreplication, also known as endoreduplication, a specialized cell-cycle variant often associated with cell
differentiation but also frequently occurring in malignant cells, plays a role in maintaining cell fate. For our study we have
used Arabidopsis trichomes as a model system and have manipulated endoreplication levels via mutants of cell-cycle
regulators and overexpression of cell-cycle inhibitors under a trichome-specific promoter. Strikingly, a reduction of
endoreplication resulted in reduced trichome numbers and caused trichomes to lose their identity. Live observations of
young Arabidopsis leaves revealed that dedifferentiating trichomes re-entered mitosis and were re-integrated into the
epidermal pavement-cell layer, acquiring the typical characteristics of the surrounding epidermal cells. Conversely, when we
promoted endoreplication in glabrous patterning mutants, trichome fate could be restored, demonstrating that
endoreplication is an important determinant of cell identity. Our data lead to a new model of cell-fate control and
tissue integrity during development by revealing a cell-fate quality control system at the tissue level.
Description:
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
