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Genetics. Jan 1993; 133(1): 119–125.
PMCID: PMC1205291

Unequal Exchange and Meiotic Instability of Disease-Resistance Genes in the Rp1 Region of Maize

Abstract

The Rp1 region of maize was originally characterized as a complex locus which conditions resistance to the fungus Puccinia sorghi, the causal organism in the common rust disease. Some alleles of Rp1 are meiotically unstable, but the mechanism of instability is not known. We have studied the role of recombination in meiotic instability in maize lines homozygous for either Rp1-J or Rp1-G. Test cross progenies derived from a line that was homozygous for Rp1-J, but heterozygous at flanking markers, were screened for susceptible individuals. Five susceptible individuals were derived from 9772 progeny. All five had nonparental combinations of flanking markers; three had one combination of recombinant flanking markers while the other two had the opposite pair. In an identical study with Rp1-G, 20 susceptible seedlings were detected out of 5874 test cross progeny. Nineteen of these were associated with flanking marker exchange, 11 and 8 of each recombinant marker combination. Our results indicate that unequal exchange is the primary mechanism of meiotic instability of Rp1-J and Rp1-G.

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Selected References

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  • Burr B, Burr FA, Thompson KH, Albertson MC, Stuber CW. Gene mapping with recombinant inbreds in maize. Genetics. 1988 Mar;118(3):519–526. [PMC free article] [PubMed]
  • Davis PS, Shen MW, Judd BH. Asymmetrical pairings of transposons in and proximal to the white locus of Drosophila account for four classes of regularly occurring exchange products. Proc Natl Acad Sci U S A. 1987 Jan;84(1):174–178. [PMC free article] [PubMed]
  • Dooner HK. Genetic Fine Structure of the BRONZE Locus in Maize. Genetics. 1986 Aug;113(4):1021–1036. [PMC free article] [PubMed]
  • Goldberg ML, Sheen JY, Gehring WJ, Green MM. Unequal crossing-over associated with asymmetrical synapsis between nomadic elements in the Drosophila melanogaster genome. Proc Natl Acad Sci U S A. 1983 Aug;80(16):5017–5021. [PMC free article] [PubMed]
  • HAGAN WL, HOOKER AL. GENETICS OF REACTION TO PUCCINIA SORGHI IN ELEVEN CORN INBRED LINES FROM CENTRAL AND SOUTH AMERICA. Phytopathology. 1965 Feb;55:193–197. [PubMed]
  • Hipeau-Jacquotte R, Brutlag DL, Brégégère F. Conversion and reciprocal exchange between tandem repeats in Drosophila melanogaster. Mol Gen Genet. 1989 Dec;220(1):140–146. [PubMed]
  • Hooker AL, Saxena KM. Genetics of disease resistance in plants. Annu Rev Genet. 1971;5:407–424. [PubMed]
  • Horsthemke B, Beisiegel U, Dunning A, Havinga JR, Williamson R, Humphries S. Unequal crossing-over between two alu-repetitive DNA sequences in the low-density-lipoprotein-receptor gene. A possible mechanism for the defect in a patient with familial hypercholesterolaemia. Eur J Biochem. 1987 Apr 1;164(1):77–81. [PubMed]
  • Hu XY, Ray PN, Worton RG. Mechanisms of tandem duplication in the Duchenne muscular dystrophy gene include both homologous and nonhomologous intrachromosomal recombination. EMBO J. 1991 Sep;10(9):2471–2477. [PMC free article] [PubMed]
  • Hulbert SH, Bennetzen JL. Recombination at the Rp1 locus of maize. Mol Gen Genet. 1991 May;226(3):377–382. [PubMed]
  • Jackson JA, Fink GR. Meiotic recombination between duplicated genetic elements in Saccharomyces cerevisiae. Genetics. 1985 Feb;109(2):303–332. [PMC free article] [PubMed]
  • Keen NT. Gene-for-gene complementarity in plant-pathogen interactions. Annu Rev Genet. 1990;24:447–463. [PubMed]
  • Maloney DH, Fogel S. Gene conversion, unequal crossing-over and mispairing at a non-tandem duplication during meiosis of Saccharomyces cerevisiae. Curr Genet. 1987;12(1):1–7. [PubMed]
  • Nelson OE. The Waxy Locus in Maize. I. Intralocus Recombination Frequency Estimates by Pollen and by Conventional Analyses. Genetics. 1962 Jun;47(6):737–742. [PMC free article] [PubMed]
  • Nicholls RD, Fischel-Ghodsian N, Higgs DR. Recombination at the human alpha-globin gene cluster: sequence features and topological constraints. Cell. 1987 May 8;49(3):369–378. [PubMed]
  • Saxena KM, Hooker AL. On the structure of a gene for disease resistance in maize. Proc Natl Acad Sci U S A. 1968 Dec;61(4):1300–1305. [PMC free article] [PubMed]
  • Shepherd KW, Mayo GM. Genes conferring specific plant disease resistance. Science. 1972 Jan 28;175(4020):375–380. [PubMed]
  • Weber D, Helentjaris T. Mapping RFLP loci in maize using B-A translocations. Genetics. 1989 Mar;121(3):583–590. [PMC free article] [PubMed]
  • Wise RP, Ellingboe AH. Fine structure and instability of the Ml-a locus in barley. Genetics. 1985 Sep;111(1):113–130. [PMC free article] [PubMed]

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