FACS analysis of the planarian stem cell compartment as a tool to understand regenerative mechanisms.

Planarians provide a relatively simple model system in which to study stem cell dynamics and regenerative phenomena. As with other systems understanding the dynamics of stem cell and stem cell progeny is crucial in order to get at the molecular mechanisms orchestrating stem cell biology. Planarians have an abundant adult stem cell population that can be observed using Fluorescence-Activated Cell Sorting (FACS).

Combining classical and molecular approaches elaborates on the complexity of mechanisms underpinning anterior regeneration.

The current model of planarian anterior regeneration evokes the establishment of low levels of Wnt signalling at anterior wounds, promoting anterior polarity and subsequent elaboration of anterior fate through the action of the TALE class homeodomain PREP. The classical observation that decapitations positioned anteriorly will regenerate heads more rapidly than posteriorly positioned decapitations was among the first to lead to the proposal of gradients along an anteroposterior (AP) axis in a developmental context. An explicit understanding of this phenomenon is not included in the current model of anterior regeneration.