, Volume 39, Issue 1, pp 245–249 | Cite as

Ascospore linearity in the four-spored ascus ofNeurospora tetrasperma

  • Ford Calhoun
  • H. Branch HoweJr.


The four-spored ascus ofNeurospora tetrasperma is linearly ordered, i.e. the order of the ascospores within the linear ascus directly reflects preceding meiotic events. This conclusion is based upon the finding of only two types of arrangements of homokaryotic ascospores in asci showing second division segregation and the failure to find any of the other four theoretically possible types of homokaryotic arrangements. The data are also consistent with the regular occurrence of nuclear passing at both the second and third meiotic divisions during ascus development.


Ascus Meiotic Division Regular Occurrence Meiotic Event Ascus Development 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Braver, N. B. (1952). Genetic segregations inNeurospora tetrasperma. M. S. Thesis, University of Missouri, Columbia, Missouri.Google Scholar
  2. Catcheside, D. G. (1951).The Genetics of Microorganisms. Pitman, London.Google Scholar
  3. Colson, B. (1934). The cytology and morphology ofNeurospora tetrasperma Dodge.Ann. Botany 48: 211–224.Google Scholar
  4. Dodge, B. O. (1927). Nuclear phenomena associated with heterothallism and homothallism in the ascomycete, Neurospora.J. Agric. Res. 35: 289–305.Google Scholar
  5. Dopge, B. O., M. B. Schmitt & A. Appel (1945). Inheritance of factors involved in one type of heterokaryotic vigor.Proc. Am. Philos. Soc. 89: 575–589.Google Scholar
  6. Howe, H. B. (1963). Markers and centromere distances inNeurospora tetrasperma.Genetics 48: 121–131.PubMedGoogle Scholar
  7. Howe, H. B. (1964). Sources of error in genetic analysis inNeurospora tetrasperma.Genetics 50: 181–189.PubMedGoogle Scholar
  8. Howe, H. B. & P. Haysman (1966). Linkage group establishment inNeurospora tetrasperma by interspecific hybridization withN. crassa.Genetics 54: 292–302.Google Scholar
  9. Johnson, J. W. (1963). Genetic studies ofNeurospora tetrasperma. M. S. Thesis, Cornell University, Ithaca, N. Y.Google Scholar
  10. Malloch, W. S. (1940). The artificial induction of mutations inNeurospora tetrasperma. Ph. D. Thesis, University of California, Berkeley, California.Google Scholar
  11. Malloch, W. S. (1942). The inheritance of induced mutations inNeurospora tetrasperma.Mycologia 34: 325–347.Google Scholar
  12. Pincheira, G. (1963). Normal and abnormal spindle behavior inNeurospora crassa andNeurospora tetrasperma. M. S. Thesis, Cornell University, Ithaca, N. Y.Google Scholar
  13. Sansome, E. R. (1946). Maintenance of heterozygosity in a homothallic species of theNeurospora tetrasperma type.Nature 157: 484–485.Google Scholar
  14. Westergaard, M. & H. K. Mitchell (1947). Neurospora. V. A synthetic medium favouring sexual reproduction.Am. J. Botany 34: 573–577.Google Scholar

Copyright information

© Martinus Nijhoff 1968

Authors and Affiliations

  • Ford Calhoun
    • 1
  • H. Branch HoweJr.
    • 1
  1. 1.Department of MicrobiologyUniversity of GeorgiaAthensUSA

Personalised recommendations