Analysis of the dynamics of the growing and branching network of filamentous fungus Podospora anserina.

The success of filamentous fungi in colonizing most natural environments can be largely attributed to their ability to form an expanding interconnected network, the mycelium, or thallus, constituted by a collection of growing hyphal apexes producing hyphae and subject to branching and fusion. In this work, we characterize the hyphal network expansion and the structure of the filamentous fungus Podospora anserina under controlled culture conditions. To this end, temporal series of pictures of the network dynamics are produced, starting from germinating ascospores (1 node) and ending when the network reaches thousands of connections. The completely automated image reconstruction steps allow a post-processing and a quantitative analysis of the spatio-temporal dynamics. Taking advantage of the network's properties we can numerically identify each individual hypha and its nature (apical or lateral). With this method we plan to discriminate hyphal fusion (anastomoses) from mere overlapping. Thanks to the reconstruction of each hypha, we can analyse the growth of the network at both local and global scale.