Claire Miller’s new preprint is available now on arXiv.

https://arxiv.org/abs/1811.10781

In epithelial tissues such as skin, stem cells divide in order to replace cells that are lost at the surface. The maintenance of the stem cell niche is therefore an important component of any mathematical model of an epithelial tissue. In this paper we investigate how current modelling methods can result in erroneous loss of stem cells from the stem cell niche. Using established models of skin we find we are unable to maintain a stem cell population without including additional unbiological mechanisms. We suggest an alternative modelling methodology to maintain the stem cell niche in which a rotational force is applied to the two daughter cells during the mitotic phase of division to enforce a particular division direction. This methodology reflects the regulation of orientation of the mitotic spindle during the final phase of the cell cycle. We show using an agent-based multicellular model of human skin that this additional, biologically plausible mechanism is sufficient to maintain the stem cell niche.