Ultraviolet-inactivation of conidia from heterokaryons of Neurospora crassa containing uv-sensitive mutations

Conference · Mon Jan 01 04:00:00 EST 1973

OSTI ID:4312433

Shelby, M D; de Serres, F J; Stine, G J

From 7th neurospora information conference; Asilomar, California, USA (25 Mar 1974). The effect of three uv-sensitive mutations of Neurospora crassa, upr-1, uvs-4 and uvs-6, on the ultraviolet-inactivation of conidia from two- component heterokaryons was investigated. In twocomponent heterokaryons with wild-type sensitivity to radiation inactivation, all three conidial fractions exhibited similar ultraviolet-inactivation curves. Each uv-sensitive mutation studied uniquely modified the ultraviolet-inactivation curves of conidia from two- component heterokaryons. In heterokaryons heterokaryotic for upr-1, the upr-1 mutation was recessive and the repair function determined by the wild-type allele was functional to some degree in homokaryotic upr-1 conidia. All three conidial fractions of heterokaryons containing upr-1 in both components showed increased sensitivity to ultraviolet light. The uvs-4 mutation was recessive and resulted in conidia with increased uv-sensitivity only when included in both components of a heterokaryon. Homokaryotic uvs-4 conidia, which arose from heterokaryons containing both uvs-4 and wild-type components, exhibited wild-type survival. Therefore, as with upr-1, there was a carryover of the repair capability to conidia which were genetically uv-sensitive. The uvs-6 mutation, when included in one component of a two-component heterokaryon, resulted in increased uv- sensitivity of both heterokaryotic and homokaryotic uvs-6 conidia. When both components contained uvs-6, the uv-sensitivity of all three conidial fractions was increased and all showed similar inactivation curves. Thus, as with upr-1 and uvs-4, there was a carryover of the wildtype repair capability to geneticaily uvs-6 conidia. Heterokaryon tests for complementation between two non-allelic uv- sensitive mutations showed that in heterokaryotic conidia, complete complementation occurred between upr-1 and uvs-4. (auth)

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• NSA Number: NSA-29-029679
• OSTI ID: 4312433
• Report Number(s): CONF-740303--1
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*CONIDIA-- INACTIVATION
*MUTATIONS-- RADIOINDUCTION
*NEUROSPORA-- MUTATIONS
BIOLOGICAL RADIATION EFFECTS
N48310* --Life Sciences--Radiation Effects on Microorganisms- -Basic Studies
PHOTON BEAMS
RADIOSENSITIVITY
ULTRAVIOLET RADIATION RADIOINDUCTION