Stem cell decisions, a twist of fate or a niche market?

Seminars in cell & developmental biology

PubMedID: 24613913

Januschke J, Näthke I. Stem cell decisions, a twist of fate or a niche market?. Semin Cell Dev Biol. 2014;.
One of the central questions in cell and developmental biology is how differences in cells are established and maintained. In multicellular organisms this problem is not restricted to development but is also relevant during tissue homeostasis in the adult. One mechanism for establishing different cell fates is asymmetric cell division. In this context, the transmission of cell fate information can occur through cell-cell communication, it can be established via intracellular polarity or it can be inherited from one cell generation to the next [1]. Stem cells are one cell type that can divide asymmetrically to produce a self-renewed stem cell and a daughter cell that will differentiate. Stem cells can also divide symmetrically to expand the stem cell pool. Increasing stem cell numbers or generating differentiating cells is a key process in building and maintaining tissues. In the context of stem cells the orientation of the mitotic spindle can influence the fate of daughter cells [1,2]. The correct alignment of mitotic spindles is not only important in development but defects in this process are also associated with disease [3,4]. It is thus not surprising that controlling the orientation of mitosis is an important issue for tissue morphogenesis [5-7]. The different requirements and contexts in which stem cells are found predict that a plethora of regulatory mechanisms operate to govern spindle orientation and cell fate decisions. Here we discuss intrinsic and extrinsic cues that are involved in asymmetric stem cell division and focus specifically on the contribution of selective centrosome segregation.