Morphodynamics of non-canonical autophagic structures in Neurospora crassa

Neurospora is a quintessential tip-growing organism, which is well known for packaging and longitudinal transport of tip-building blocks. Thus far, however, little attention has been paid to the co-essential process of reclamation, that is-taking apart of upstream, older structural elements, otherwise known as "autophagy". We are not yet prepared to set out the chemistry of that elaborate process, but its morphological start alone is worthy of attention. Carbon starvation triggers significant autophagic changes, beginning with prolific vacuolation along the plasma membrane, and eventual filling of 70% (or more) of cytoplasmic volume. Additionally, the Neurospora plasma membrane elaborates a variety of phagophores which themselves often look lytic. These have either dual enclosing membranes, like the familiar autophagosomes, can be doubled and have four wrapping membranes, or can be compounded with multiple membrane layers. These reclamation processes must be accommodated by the mechanism of tip growth.