• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Dec 1984; 81(24): 8014–8018.
PMCID: PMC392284

Ribosomal DNA spacer-length polymorphisms in barley: mendelian inheritance, chromosomal location, and population dynamics.

Abstract

Spacer-length (sl) variation in ribosomal RNA gene clusters (rDNA) was surveyed in 502 individual barley plants, including samples from 50 accessions of cultivated barley, 25 accessions of its wild ancestor, and five generations of composite cross II (CCII), an experimental population of barley. In total, 17 rDNA sl phenotypes, made up of 15 different rDNA sl variants, were observed. The 15 rDNA sl variants comprise a complete ladder in which each variant differs in length from adjacent variants by approximately equal to 115 nucleotide pairs. Studies of four rDNA sl variants in an F2 population showed that these variants are located at two unlinked loci, Rrn1 and Rrn2, each with two codominant alleles. Using wheat-barley addition lines, we determined that Rrn1 and Rrn2 are located on chromosomes 6 and 7, respectively. The nonrandom distribution of sl variants between loci suggests that genetic exchange occurs much less frequently between than within the two loci, which demonstrates that Rrn1 and Rrn2 are useful as new genetic markers. Frequencies of rDNA sl phenotypes and variants were monitored over 54 generations in CCII. A phenotype that was originally infrequent in CCII ultimately became predominant, whereas the originally most frequent phenotype decreased drastically in frequency, and all other phenotypes originally present disappeared from the population. We conclude that the sl variants and/or associated loci are under selection in CCII.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.2M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Long EO, Dawid IB. Repeated genes in eukaryotes. Annu Rev Biochem. 1980;49:727–764. [PubMed]
  • Arnheim N, Treco D, Taylor B, Eicher EM. Distribution of ribosomal gene length variants among mouse chromosomes. Proc Natl Acad Sci U S A. 1982 Aug;79(15):4677–4680. [PMC free article] [PubMed]
  • Krystal M, D'Eustachio P, Ruddle FH, Arnheim N. Human nucleolus organizers on nonhomologous chromosomes can share the same ribosomal gene variants. Proc Natl Acad Sci U S A. 1981 Sep;78(9):5744–5748. [PMC free article] [PubMed]
  • Coen ES, Thoday JM, Dover G. Rate of turnover of structural variants in the rDNA gene family of Drosophila melanogaster. Nature. 1982 Feb 18;295(5850):564–568. [PubMed]
  • Murray MG, Thompson WF. Rapid isolation of high molecular weight plant DNA. Nucleic Acids Res. 1980 Oct 10;8(19):4321–4325. [PMC free article] [PubMed]
  • Southern EM. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol. 1975 Nov 5;98(3):503–517. [PubMed]
  • Gerlach WL, Bedbrook JR. Cloning and characterization of ribosomal RNA genes from wheat and barley. Nucleic Acids Res. 1979 Dec 11;7(7):1869–1885. [PMC free article] [PubMed]
  • Rigby PW, Dieckmann M, Rhodes C, Berg P. Labeling deoxyribonucleic acid to high specific activity in vitro by nick translation with DNA polymerase I. J Mol Biol. 1977 Jun 15;113(1):237–251. [PubMed]
  • Hakim-Elahi A. Computer program for calculating recombination values from electrophoretic data. J Hered. 1984 Mar-Apr;75(2):150–151. [PubMed]
  • Allard RW, Kahler AL, Weir BS. The effect of selection on esterase allozymes in a barley population. Genetics. 1972 Nov;72(3):489–503. [PMC free article] [PubMed]
  • Clegg MT, Kahler AL, Allard RW. Estimation of life cycle components of selection in an experimental plant population. Genetics. 1978 Aug;89(4):765–792. [PMC free article] [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

  • MedGen
    MedGen
    Related information in MedGen
  • PubMed
    PubMed
    PubMed citations for these articles
  • Substance
    Substance
    PubChem Substance links

Recent Activity

    Your browsing activity is empty.

    Activity recording is turned off.

    Turn recording back on

    See more...