We recommend the following references if you wish to investigate fungal introns further at this point in the module

The fact that genes are split or interrupted by what came to be called introns was discovered independently in 1977 by P. A. Sharp and R. J. Roberts, who were working on protein-coding genes of adenovirus. Introns are now known to occur in a wide variety of genes and in organisms and viruses in all of the biological kingdoms. Shepelev, V. & Fedorov, A. (2006). Advances in the Exon-Intron Database (EID). Briefings in Bioinformatics, 7: 178–185. DOI: https://doi.org/10.1093/bib/bbl003. And see this URL: http://bpg.utoledo.edu/~afedorov/lab/eid.html [unfortunately, there were no fungi in the data base when we wrote this] The Nobel Prize in Physiology or Medicine 1993 was awarded jointly to Sir Richard J. Roberts and Phillip A. Sharp for ‘…their discovery that genes in eukaryotes are not contiguous strings but contain introns, and that the splicing of messenger RNA to delete those introns can occur in different ways, yielding different proteins from the same DNA sequence…’ [see Nobel Prize website]. Sharp, P.A. (2005). The discovery of split genes and RNA splicing. Trends in Biochemical Sciences, 30: 279-281. DOI: https://doi.org/10.1016/j.tibs.2005.04.002. The term intron was introduced by American biochemist Walter Gilbert: ‘The notion of the cistron ... must be replaced by that of a transcription unit containing regions which will be lost from the mature messenger - which I suggest we call introns (for intragenic regions) - alternating with regions which will be expressed - exons.’ Gilbert, W. (1978). Why genes in pieces? Nature, 271: 501. DOI: https://doi.org/10.1038/271501a0. Analyses of gene structures in different organisms have identified numerous intron gain and loss events that have occurred both recently and throughout the distant evolutionary past. Yenerall, P. & Zhou, L. (2012). Identifying the mechanisms of intron gain: progress and trends. Biology Direct, 7: 29 (10 pp). DOI: https://doi.org/10.1186/1745-6150-7-29. Little is known about these processes but genome-wide analyses of distant species differing in their intron content, has shown that intron-containing genes, and the intron-richest genomes, are best protected against genetic instability that can result from transcription errors that damage the template DNA. This provides a possible rationale for the conservation of introns in eukaryotes. Bonnet, A., Grosso, A.R., Elkaoutari, A., Coleno, E., Presle, A., Sridhara, S.C., Janbon, G., Géli, V., de Almeida, S.F. & Palancade, B. (2017). Introns protect eukaryotic genomes from transcription-associated genetic instability. Molecular Cell, 67: 608-621.e6. DOI: https://doi.org/10.1016/j.molcel.2017.07.002. The exon-intron structure of protein-coding genes appears to have evolved along with the eukaryotic cell; introns being a major factor of evolution throughout the history of eukaryotes. Rogozin, I.B., Carmel, L., Csuros, M. & Koonin, E.V. (2012). Origin and evolution of spliceosomal introns. Biology Direct, 7: 11. DOI: http://doi.org/10.1186/1745-6150-7-11.

Close the window to return to 21st Century Guidebook to Fungi

This is a Resources Box from the 21st Century Guidebook to Fungi: © David Moore, Geoffrey D. Robson and Anthony P. J. Trinci 2019