Endoreplication Controls Cell Fate Maintenance

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.

Jasmonate Controls Leaf Growth by Repressing Cell Proliferation and the Onset of Endoreduplication while Maintaining a Potential Stand-By Mode

“…Recently, the occurrence of endoreduplication has been associated with an increased potential for further cell functions , such as the capacity for future cellular growth (Breuer et al, 2010), the regulation of responses against plant pathogen attacks (Chandran et al, 2010;Wildermuth, 2010), or a role in the maintenance of cell fate (Bramsiepe et al, 2010). In terms of cellular machinery, although basic plant cell cycle and growth regulators have become increasingly well characterized during Arabidopsis development (Gutierrez, 2009;Boruc et al, 2010;Van Leene et al, 2010, 2011, little is known about their precise regulation/ coordination.…”

DELLA Signaling Mediates Stress-Induced Cell Differentiation in Arabidopsis Leaves through Modulation of Anaphase-Promoting Complex/Cyclosome Activity

“…Endoreduplication generally correlates with cell expansion and differentiation, but its physiological role is still under debate and is likely tissue and stimulus specific . One intriguing hypothesis is that endoreduplication ensures cell fate maintenance by preventing dedifferentiation (Bramsiepe et al, 2010).…”

CULLIN 4-RING FINGER-LIGASE plays a key role in the control of endoreplication cycles in Arabidopsis trichomes

“…Endoreplication has been found to play a developmental role in controlling cell size and regulating cell morphology, and an increased DNA content is typically associated with larger cells (2,4). In addition, a recent report identified a function of endoreplication in maintaining cell fate (7). Besides these developmental roles, it is believed that endocycles are important for promoting cell physiological functions, e.g., by increasing DNA templates for RNA production.…”