Skip to main content
Open Access Publications from the University of California

UC Riverside

UC Riverside Previously Published Works bannerUC Riverside

Septum Development in Neurospora crassa: The Septal Actomyosin Tangle


Septum formation in Neurospora crassa was studied by fluorescent tagging of actin, myosin, tropomyosin, formin, fimbrin, BUD-4, and CHS-1. In chronological order, we recognized three septum development stages: 1) septal actomyosin tangle (SAT) assembly, 2) contractile actomyosin ring (CAR) formation, 3) CAR constriction together with plasma membrane ingrowth and cell wall construction. Septation began with the assembly of a conspicuous tangle of cortical actin cables (SAT) in the septation site >5 min before plasma membrane ingrowth. Tropomyosin and myosin were detected as components of the SAT from the outset. The SAT gradually condensed to form a proto-CAR that preceded CAR formation. During septum development, the contractile actomyosin ring remained associated with the advancing edge of the septum. Formin and BUD-4 were recruited during the transition from SAT to CAR and CHS-1 appeared two min before CAR constriction. Actin patches containing fimbrin were observed surrounding the ingrowing septum, an indication of endocytic activity. Although the trigger of SAT assembly remains unclear, the regularity of septation both in space and time gives us reason to believe that the initiation of the septation process is integrated with the mechanisms that control both the cell cycle and the overall growth of hyphae, despite the asynchronous nature of mitosis in N. crassa.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View