How to build a fungal fruit body: from uniform cells to specialized tissue.

It is a challenge in biology to explore the molecular and cellular mechanisms necessary to form a complex three-dimensional structure composed of different cell types. Interesting models to study the underlying processes are fungi that can transform their wire-like hyphal filaments into complex and sometimes container-like fruit bodies. In the past, the role of developmental triggers and transcription factors was a major focus of research on fungal model organisms. In this issue of Molecular Microbiology, Nowrousian and collaborators report that fruit body development of the model organism Sordaria macrospora includes a novel player, a specific membrane protein of the endoplasmic reticulum that is not required for vegetative growth. This finding represents an important step towards connecting regulation of development with the co-ordinated changes in cellular compartments.