Gene controlled heterocaryon instability in Neurospora crassa

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Charles Parker Calligan (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
James Wilson

Abstract: A second heterocaryon gene has been identified in Neurospora that affects the maintenance of stable growth rates of heterocaryons, rather than heterocaryon formation, as do the genes C, D, and E. The alleles of the new gene have been tentatively designated HI and hi, for heterocaryon instability. On growth tubes, forced HI + HI and hi + hi heterocaryons grow normally. HI + hi heterocaryons grow at wild type rate initially, then growth slows or ceases. The behavior of HI + hi heterocaryons appears to be unrelated to nutritional requirements of the component strains. Results of conidial platings and single hyphal tip isolations from unstable heterocaryons suggest (1) a greatly reduced number of hi nuclei in conidia and hyphae growing from the conidial inoculum, (2) that migration of hi nuclei is not totally inhibited. Direct observations show that HI and hi conidia germinate and fuse normally. The behavior of HI + hi heterocaryona appears to be independent of initial nuclear ratios, unlike that of the previously described I + i heterocaryons. These results suggest a nonadaptive change in nuclear ratios of the unstable heterocaryons. We have been unable to determine whether this change is a result of selective mitotic inhibition, interference with nuclear migration, or a combination of both. Preliminary genetic analysis suggests that the new gene is on the left arm of linkage group II.

Additional Information

Language: English
Date: 1976
Neurospora crassa
Neurospora crassa $x Genetics

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