Abstract
The Tad transposon of Neurospora crassa appears to be a LINE-like element with very restricted distribution within the genus Neurospora. When forced heterokaryons were constructed between strains which did and did not contain Tad, the nuclei of the naive nuclear type rapidly acquired Tad elements. The elements acquired by naive nuclei are active, since they can pass Tad to other naive nuclei in subsequent heterokaryons. When heterokaryons are passaged by serial transfer, the load of acquired Tad elements appears to increase, indicating that transposition is continuing in these heterokaryons, even after all of the naive nuclei have acquired Tad. In normal heterokaryons of Neurospora, nuclei do not fuse. An experiment to test for the possibility that Tad promotes nuclear fusion gave negative results. Thus Tad appears to have a cytoplasmic intermediate in its transposition. When heterokaryon incompatible strains were cocultured, there was no indication that Tad elements could be transferred to the naive strain, suggesting that Tad is not a virus. These data are consistent with the transposition of Tad via RNA and cDNA intermediates, as has been postulated to occur with LINE-like elements.
Full Text
The Full Text of this article is available as a PDF (3.8 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bucheton A. I transposable elements and I-R hybrid dysgenesis in Drosophila. Trends Genet. 1990 Jan;6(1):16–21. doi: 10.1016/0168-9525(90)90044-7. [DOI] [PubMed] [Google Scholar]
- Fawcett D. H., Lister C. K., Kellett E., Finnegan D. J. Transposable elements controlling I-R hybrid dysgenesis in D. melanogaster are similar to mammalian LINEs. Cell. 1986 Dec 26;47(6):1007–1015. doi: 10.1016/0092-8674(86)90815-9. [DOI] [PubMed] [Google Scholar]
- Kinsey J. A. Direct selective procedure for isolating Neurospora mutants defective in nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase. J Bacteriol. 1977 Dec;132(3):751–756. doi: 10.1128/jb.132.3.751-756.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kinsey J. A., Helber J. Isolation of a transposable element from Neurospora crassa. Proc Natl Acad Sci U S A. 1989 Mar;86(6):1929–1933. doi: 10.1073/pnas.86.6.1929. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kinsey J. A. Restricted distribution of the Tad transposon in strains of Neurospora. Curr Genet. 1989 Apr;15(4):271–275. doi: 10.1007/BF00447042. [DOI] [PubMed] [Google Scholar]
- Perkins D. D. The use of duplication-generating rearrangements for studying heterokaryon incompatibility genes in Neurospora. Genetics. 1975 May;80(1):87–105. doi: 10.1093/genetics/80.1.87. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Xiong Y., Eickbush T. H. Similarity of reverse transcriptase-like sequences of viruses, transposable elements, and mitochondrial introns. Mol Biol Evol. 1988 Nov;5(6):675–690. doi: 10.1093/oxfordjournals.molbev.a040521. [DOI] [PubMed] [Google Scholar]
- Xiong Y., Eickbush T. H. The site-specific ribosomal DNA insertion element R1Bm belongs to a class of non-long-terminal-repeat retrotransposons. Mol Cell Biol. 1988 Jan;8(1):114–123. doi: 10.1128/mcb.8.1.114. [DOI] [PMC free article] [PubMed] [Google Scholar]