Duplicating the mold: Branching of fungal hyphae

A defining feature of filamentous fungi is the ability to form branched hyphae that facilitate the efficient colonization of ecological niches. Two distinct branching patterns have been recognized in fungal hyphae; apical branching and lateral branching. The use of physiological approaches and image analysis has generated sufficient data to enable the development of robust models that predict branching behavior. However, insight into the molecular mechanisms that underlie branching has lagged. The intent of this review is to summarize processes that are known to contribute to the regulation of branching and the morphogenesis of branches. Potential directions for future study will also be suggested. Ultimately, advances in understanding hyphal branching will likely be best achieved using a "design-build-test-learn" approach that combines genetic analyses in model systems with ensemble modeling that generates testable predictions.