Both the formation and function of the epithelial sheets that form most of our organs depends on the apical-basal (top-bottom) polarisation of each cell, whereas a loss of this polarity is a hallmark for cancer. It has generally been assumed that all epithelia are polarised by a common mechanism involving a conserved set of polarity factors. In their new publication, Professor Daniel St Johnston’s Group at the Gurdon Institute show that none of these factors are required for polarity in the fly midgut epithelium, indicating that there are at least two types of epithelia that polarise by fundamentally different mechanisms. Furthermore, their findings reveal that the Drosophila midgut is more similar to most mammalian epithelia than other fly epithelia, suggesting that it will be a good model for studying how cells within epithelial sheets polarise and how this polarity is disturbed in cancer.
