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Monitoring Neuronal Survival via Longitudinal Fluorescence Microscopy
Published on: January 19, 2019
INFLUENCE OF DEATH CRITERIA ON THE X-RAY SURVIVAL CURVES OF THE FUNGUS, NEUROSPORA
1Department of Botany, University of California, Berkeley.
Abstract:
1. When ascospores of Neurospora tetrasperma were irradiated with 11 kv. X-rays, the single spore cultures obtained displayed a wide variety of mutated forms. 2. Control germinations of ascospores showed uniform behavior, ranging from 92-95 per cent germination. 3. The shape of the survival curves was found to be a function of the criterion of death. The following criteria were used: germination, growth, production of mature ascospores, and the production of normal perithecia. 4. The germination survival curve exhibited a rhythmic variation with dosage. Germination is not a significant criterion of death. 5. Half-survival dosages for growth and ascospore production were approximately 30,000 and 20,000 roentgens, respectively. 6. Multiple hit-to-kill relations were found on the basis of the quantum hit theory; no accurate analysis was possible. 7. The studies indicate that ascospore death does not result from a single well defined reaction, but rather from the integrated effects of several deleterious processes initiated by the radiation.
Insights
X-ray irradiation of Neurospora tetrasperma ascospores induced diverse mutations. Survival curves varied with death criteria, indicating radiation effects result from multiple processes, not a single reaction.
Area of Science:
- Radiation biology
- Mycology
- Genetics
Background:
- Neurospora tetrasperma is a model organism for genetic studies.
- Ascospores are reproductive cells crucial for fungal propagation.
Purpose of the Study:
- To investigate the effects of X-ray irradiation on Neurospora tetrasperma ascospores.
- To characterize survival curves based on different lethality criteria.
- To explore the mechanisms of radiation-induced cell death.
Main Methods:
- Irradiation of Neurospora tetrasperma ascospores with 11 kv. X-rays.
- Single spore culturing to observe mutations.
- Assessment of survival based on germination, growth, ascospore production, and perithecia formation.
Main Results:
- X-ray exposure resulted in a wide spectrum of mutated forms.
- Survival curves were dependent on the chosen criterion for death.
- Half-survival dosages for growth and ascospore production were approximately 30,000 and 20,000 roentgens.
- Germination was not a reliable indicator of radiation-induced death.
Conclusions:
- Radiation-induced death in ascospores is a complex outcome of multiple detrimental processes.
- The quantum hit theory suggested multiple hits are involved, but precise analysis was limited.
- Ascospore death is not attributable to a single, well-defined radiation reaction.
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