The origin and behavior of mutable loci in maize

McClintock, Barbara (June 1950) The origin and behavior of mutable loci in maize. Proceedings of the National Academy of Sciences, 36 (6). pp. 344-355.

URL: https://www.ncbi.nlm.nih.gov/pubmed/15430309

Abstract

In the course of an experiment designed to reveal the genic composition of the short arm of chromosome 9, a phenomenon of rare occurrence (or recognition) in maize began to appear with remarkably high frequencies in the cultures. The terms mutable genes, unstable genes, variegation, mosaicism, mutable loci or “position-effect” have been applied to this phenomenon. Its occurrence in a wide variety of organisms has been recognized. The most extensive investigations of this phenomenon have been undertaken in Drosophila melanogaster.1 In this organism, the conditions associated with the origin of genic instability have been well defined. The part played by the heterochromatic materials of the chromosomes, in inducing and controlling the type of variegation and its time and frequency of occurrence, has been established. It has not been generally recognized that the instability of genic expression in other organisms may be essentially the same as that occurring in Drosophila. As stated above, a large number of mutable loci have recently arisen in the maize cultures and are continuing to arise anew. The loci affect variegation for many different kinds of plant characters, each locus being concerned with a particular character or occasionally several characters. Some of these loci are c, yg2, wx, a2, y, pyd, which are well-investigated units in maize.2 Others involve previously unknown genetic units. The same types of genic instability appearing in the maize cultures have been described in many other organisms. The behavior of these new mutable loci in maize cannot be considered peculiar to this organism. The author believes that the mechanism underlying the phenomenon of variegation is basically the same in all organisms. The reasons for this conclusion will be made apparent in the discussion.

Item Type: Paper
Subjects: organism description > plant > maize
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromosome
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromosomes, structure and function > chromosome

bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > mutations
CSHL Authors:
Communities: CSHL labs > McClintock lab
Depositing User: Matt Covey
Date: June 1950
Date Deposited: 25 Apr 2017 19:03
Last Modified: 25 Apr 2017 19:03
PMCID: PMC1063197
Related URLs:
URI: http://repository.cshl.edu/id/eprint/34603

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