The Cold Shock Response of Neurospora crassa Pertaining to Temperature and Light Conditions

Faculty Sponsor

Michael Watters


Arts and Sciences



ORCID Identifier(s)


Document Type

Poster Presentation

Symposium Date

Summer 7-30-2018


The filamentous fungus Neurospora crassa exhibits a characteristic, temporary change in morphology when shifted from warmer incubation temperatures into the cold. This change was termed the “cold shock response.” Other workers have suggested that the temporary morphology changes were due to the changing light conditions resulting from shifting the growing colonies from incubator to glass-fronted refrigerator. A series of experiments were conducted in order to distinguish between these two competing hypotheses. Eight samples of N. crassa were grown at 33ºC. Four of the eight were subject to constant light, and the other four were subject to constant dark. These cultures were then shifted to 4ºC while maintaining their respective light/dark exposure. The cold shock response of both the “light” and “dark” samples were similar to both conventional cold shock and each other, supported the hypothesis that the cold shock morphological response is due to temperature rather than light changes. These competing hypotheses were further tested by subjecting Neurospora crassa growth to a gradient of temperature shifts. Identical stains of N. crassa were grown first in 33ºC or 30ºC, and then subject to varying degrees of cold from 4ºC to 10ºC. The spacing and appearance of the apical branching characteristic of the cold shock response correlated with the temperature shift despite the lighting conditions being constant. These results further support the conclusion that the previously described cold shock response of Neurospora is indeed the result of the temperature shift and not the changing light conditions.

Biographical Information about Author(s)

Dr Watters is a tenured full professor of Biology at VU and has been working on the cold shock response on Neurospora for 20 years. Professor Watters has a BA from Washington University in St Louis and a PhD in Genetics from the University of Washington in Seattle.

Mason Franiak is a VU undergraduate majoring in Chemistry and Philosophy. He has been working with Neurospora since the beginning of summer research.

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