Abstract
IN the homothallic ascomycete Neurospora tetrasperma, two nuclei are normally included in each ascospore, one of mating type A and one of mating type a. N. tetrasperma is therefore normally a dikaryon and heterozygous for the Aa factors. It is interesting to note that the inclusion of an A and an a nucleus in one ascospore leads to the maintenance of heterozygosity of other factors not on the same chromosome but segregating at the same time as the Aa factors. A factor segregates at the first meiotic division if there has been no crossing-over between the factor and the centromere of the chromosome on which it is placed. If there has been such crossing-over the factor segregates at the second division. A factor placed about fifty crossover units from the centromere would be expected to show 100 percent second division segregation, apart from the effect of double cross-overs.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Dodge, B. O., Schmitt, B. Mary, and Appel, Anita, Proc. Amer. Phil. Soc., 89 4, 575 (1945).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
SANSOME, E. Maintenance of Heterozygosity in a Homothallic Species of the Neurospora tetrasperma Type. Nature 157, 484–485 (1946). https://doi.org/10.1038/157484c0
Issue Date:
DOI: https://doi.org/10.1038/157484c0
This article is cited by
-
Intratetrad mating and its genetic and evolutionary consequences
Russian Journal of Genetics (2005)
-
Genetics of secondarily homothallic basidiomycetes
Heredity (1980)
-
Ascospore linearity in the four-spored ascus ofNeurospora tetrasperma
Genetica (1968)
-
The structure and behavior of fungus nuclei
The Botanical Review (1953)
-
A comparative genetic study of the mating-type chromosomes of two species ofNeurospora
Journal of Genetics (1951)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.