Three methods of detecting respiratory variation in have been investigated. They involved the addition of dyes (pontamine sky blue and eosin yellowish) tellurite or tetrazolium to a complete medium containing ethionine. The latter prevented conidiation and enabled the colours of the colonies to be seen clearly. These methods were used to distinguish nuclear and cytoplasmic cytochrome mutants ( and ) from wild-type colonies on the basis of colour. Tetrazolium violet (2–5-diphenyl-3-(1-napthyl)-tetrazolium chloride) incorporated into modified Nagai medium with ethionine is recommended for distinguishing cytoplasmic mutants of Neurospora from wild-type. Certain other nuclear mutants were also distinguishable from wild-type in some of these tests. These were Thirty-two wild-type strains in reciprocal crosses were tested on these media to find whether these tests would distinguish any nuclear or cytoplasmic variation. No new cytoplasmic variants were found. Three new nuclear genes, (mauve on dye media), (ability to reduce tetrazolium) and (suppressor of ) are described and have been mapped. All three loci were linked to the mating type locus on chromosome 1. was found in only certain wild-type strains of mating type (e.g. 74-OR8-1), and (unable to reduce tetrazolium) was found in all wild-type strains of mating type (e.g. 74-OR23-1) and certain wild-types of mating type , a suppressor of , also suppressed and , but not suppressed , but none of the other cytoplasmic mutants.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error