Single-cell asymmetries control how groups of cells form 3-D shapes together

Scientists have developed a mathematical model showing that two types of cellular asymmetry, or 'polarity', govern the shaping of cells into sheets and tubes, according to an article in eLife. The research is a major advance in understanding the processes that allow a single cell to develop into an entire organism and could help understand what happens when cells gain or lose their polarity in diseases such as cancer. Multicellular organisms can develop highly complex structures that make up their tissues and organs and are able to regenerate perfect reproductions of these structures after injury. This requires the unfolding of sheets formed by groups of dividing and interacting cells. Although much is understood about some of the intermediate steps that occur during development and repair, we still do not know how thousands of cells together work out what shapes they need to form. There are two types of polarity known to influence how cells organize themselves into tissues and they are oriented at right angles to one another. One is apical-basal polarity, which marks the inside-outside part of our skin, and the other is planar cell polarity, which is responsible for the direction of the hairs on our skin.