- THIS ARTICLE
- Full Text (PDF)
- Alert me when this article is cited
- Alert me if a correction is posted
- SERVICES
- Similar articles in this journal
- Similar articles in PubMed
- Alert me to new issues of the journal
- Download to citation manager
- Reprints & Permissions
- CITING ARTICLES
- Citing Articles via HighWire
- Citing Articles via Google Scholar
- GOOGLE SCHOLAR
- Articles by Raju, N. B.
- Articles by Perkins, D. D.
- Search for Related Content
- PUBMED
- PubMed Citation
- Articles by Raju, N. B.
- Articles by Perkins, D. D.
Genetics, Vol 129, 25-37, Copyright © 1991
INVESTIGATIONS |
Expression of Meiotic Drive Elements Spore killer-2 and Spore killer-3 in Asci of Neurospora tetrasperma
N. B. Raju and D. D. Perkins
Department of Biological Sciences, Stanford University, Stanford, California 94305-5020
It was shown previously that when a chromosomal Spore killer factor is heterozygous in Neurospora species with eight-spored asci, the four sensitive ascospores in each ascus die and the four survivors are all killers. Sk-2(K) and Sk-3(K) are nonrecombining haplotypes that segregate with the centromere of linkage group III. No killing occurs when either one of these killers is homozygous, but each is sensitive to killing by the other in crosses of Sk-2(K) X Sk-3(K). In the present study, Sk-2(K) and Sk-3(K) were transferred by recurrent backcrosses from the eight-spored species Neurospora crassa into Neurospora tetrasperma, a pseudohomothallic species which normally makes asci with four large spores, each heterokaryotic for mating type and for any other centromere-linked genes that are heterozygous in the cross. The action of Sk-2(K) and Sk-3(K) in N. tetrasperma is that predicted from their behavior in eight-spored species. A sensitive nucleus is protected from killing if it is enclosed in the same ascospore with a killer nucleus. Crosses of Sk-2(K) X Sk-2(S), Sk-3(K) X Sk-3(S), and Sk-2(K) X Sk-3(K) all produce four-spored asci that are wild type in appearance, with the ascospores heterokaryotic and viable. The Eight-spore gene E, which shows variable penetrance, was used to obtain N. tetrasperma asci in which two to eight spores are small and homokaryotic. When killer and sensitive alleles are segregating in the presence of E, only those ascospores that contain a killer allele survive. Half of the small ascospores are killed. In crosses of Sk-2(K) X Sk-3(K) (with E heterozygous), effectively all small ascospores are killed. The ability of N. tetrasperma to carry killer elements in cryptic condition suggests a possible role for Spore killers in the origin of pseudohomothallism, with adoption of the four-spored mode restoring ascospore viability of crosses in which killing would otherwise occur.
This article has been cited by other articles:
 |
|
 |
|
  N. B. Raju, R. L. Metzenberg, and P. K. T. Shiu Neurospora Spore Killers Sk-2 and Sk-3 Suppress Meiotic Silencing by Unpaired DNA Genetics, May 1, 2007; 176(1): 43 - 52. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. J. P. Dalstra, K. Swart, A. J. M. Debets, S. J. Saupe, and R. F. Hoekstra Sexual transmission of the [Het-s] prion leads to meiotic drive in Podospora anserina PNAS, May 27, 2003; 100(11): 6616 - 6621. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. van der Gaag, A. J. M. Debets, J. Oosterhof, M. Slakhorst, J. A. G. M. Thijssen, and R. F. Hoekstra Spore-Killing Meiotic Drive Factors in a Natural Population of the Fungus Podospora anserina Genetics, October 1, 2000; 156(2): 593 - 605. [Abstract] [Full Text]
|
|
|
|
 |
|
 S. Ray, S. Park, and A Ray Pollen tube guidance by the female gametophyte Development, January 6, 1997; 124(12): 2489 - 2498. [Abstract] [PDF]
|
|