Do Paneth cells pioneer intestinal epithelial crypts?

Paneth cells appear throughout the time course of small intestinal epithelila (SIE) organoids and cluster at nascent crypts.

We can track individal Paneth cells in the SIE organoids. Over time, we find that as new Paneth cells appear, they join the other Paneth cells in polarising to a site of incipient organoid formation.

Paneth cell dynamics during crypt formation

Paneth cells can be dynamically monitored using a novel GFP reporter we have developed in the lab. In the movie on the left, we monitor crypt formation, which is accompanied by the recruitment and clustering of Paneth cells. Organoids increase in size as cells in the monolayer divide, and some of these differentiate into new Paneth cells – note the appearance of the green cells – that appear to contribute to nascent crypt formation. The image on the right contains four mature crypts demarcated by the clustered green Paneth cells.