The inside cover image, by Matthew J. Stower and Federica Bertocchini, is based on the Advanced Review The Evolution of amniote gastrulation: the blastopore‐primitive streak transition, DOI: 10.1002/wdev.262.

ImageJ and its software distribution FIJI are powerful tools for quantitative image analysis. Much of the power of ImageJ is through end user developed plugins such as the depicted ClearVolume. ClearVolume is an open‐source multichannel volume renderer that in this image is being used to visualize Drosophila neurons. Image Courtesy of the HHMI Janelia Research Campus.

The primitive streak is currently considered as the landmark of amniote gastrulation. However, a close look at gastrulation in reptiles reveals the absence of the primitive streak and the presence of a blastopore slit. We review what is known about gastrulation in the three groups that constitute the amniote clade, reptiles, avians and mammals, and the molecular mechanisms driving this morphogenetic event, with an evolutionary perspective.

In the gastric epithelium, data suggests the co‐existence of two stem cell niches, one at the base of the gland and one at the isthmus. This review discusses stem cell markers, niche factors and how the niche is mimicked in vitro to generate stem cell derived organoids.