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Genetics. 1992 Feb; 130(2): 377–384.
PMCID: PMC1204857

Molecular Analysis of the Maize Wx-B3 Allele Indicates That Precise Excision of the Transposable Ac Element Is Rare


The somatic and germinal behavior of the maize wx-B3 mutation indicates that this Ac allele rarely reverts. Endosperms containing wx-B3 display tiny and infrequent Wx revertant sectors while no significant reversion is detected when wx-B3 pollen is stained with I/KI. Previous studies of other transposable element alleles that revert infrequently have implicated low levels of element excision. Unlike these other alleles, the wx-B3 Ac element is indistinguishable from fully active Ac elements with respect to its structure, and its ability to transpose from the Wx gene or to trans-activate a Ds element. Characterization of somatic and germinal excision events lead us to conclude that excision of the wx-B3 Ac element almost always produces null alleles. Furthermore, the excellent correlation between the position of the wx-B3 mutation on the physical and genetic maps indicates that the Ac insertion is the only lesion of wx-B3. As a result, precise excision of this Ac should restore Wx function. The fact that revertant sectors and pollen grains are rare indicates that precise excision of Ac is also rare. The finding that the wx-B3 reversion frequency is comparable whether wx-B3 is hemizygous or over a wx allele with a wild-type insertion site illustrates a fundamental difference between the excision mechanisms of Ac and Drosophila P elements.

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Selected References

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  • Brink RA, Williams E. Mutable R-navajo alleles of cyclic origin in maize. Genetics. 1973 Feb;73(2):273–296. [PMC free article] [PubMed]
  • Coupland G, Plum C, Chatterjee S, Post A, Starlinger P. Sequences near the termini are required for transposition of the maize transposon Ac in transgenic tobacco plants. Proc Natl Acad Sci U S A. 1989 Dec;86(23):9385–9388. [PMC free article] [PubMed]
  • Echt CS, Schwartz D. Evidence for the Inclusion of Controlling Elements within the Structural Gene at the Waxy Locus in Maize. Genetics. 1981 Oct;99(2):275–284. [PMC free article] [PubMed]
  • Engels WR, Johnson-Schlitz DM, Eggleston WB, Sved J. High-frequency P element loss in Drosophila is homolog dependent. Cell. 1990 Aug 10;62(3):515–525. [PubMed]
  • Gloor GB, Nassif NA, Johnson-Schlitz DM, Preston CR, Engels WR. Targeted gene replacement in Drosophila via P element-induced gap repair. Science. 1991 Sep 6;253(5024):1110–1117. [PubMed]
  • Gubler U, Hoffman BJ. A simple and very efficient method for generating cDNA libraries. Gene. 1983 Nov;25(2-3):263–269. [PubMed]
  • Martienssen R, Barkan A, Taylor WC, Freeling M. Somatically heritable switches in the DNA modification of Mu transposable elements monitored with a suppressible mutant in maize. Genes Dev. 1990 Mar;4(3):331–343. [PubMed]
  • Oakley BR, Kirsch DR, Morris NR. A simplified ultrasensitive silver stain for detecting proteins in polyacrylamide gels. Anal Biochem. 1980 Jul 1;105(2):361–363. [PubMed]
  • Peacock WJ, Dennis ES, Gerlach WL, Sachs MM, Schwartz D. Insertion and excision of Ds controlling elements in maize. Cold Spring Harb Symp Quant Biol. 1984;49:347–354. [PubMed]
  • Saedler H, Nevers P. Transposition in plants: a molecular model. EMBO J. 1985 Mar;4(3):585–590. [PMC free article] [PubMed]
  • Saiki RK, Gelfand DH, Stoffel S, Scharf SJ, Higuchi R, Horn GT, Mullis KB, Erlich HA. Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase. Science. 1988 Jan 29;239(4839):487–491. [PubMed]
  • Schiefelbein JW, Raboy V, Kim HY, Nelson OE. Molecular characterization of suppressor-mutator (Spm)-induced mutations at the bronze-1 locus in maize: the bz-m13 alleles. Basic Life Sci. 1988;47:261–278. [PubMed]
  • Schwarz-Sommer Z, Gierl A, Klösgen RB, Wienand U, Peterson PA, Saedler H. The Spm (En) transposable element controls the excision of a 2-kb DNA insert at the wx allele of Zea mays. EMBO J. 1984 May;3(5):1021–1028. [PMC free article] [PubMed]
  • Schwarz-Sommer Z, Gierl A, Berndtgen R, Saedler H. Sequence comparison of 'states' of a1-m1 suggests a model of Spm (En) action. EMBO J. 1985 Oct;4(10):2439–2443. [PMC free article] [PubMed]
  • Shure M, Wessler S, Fedoroff N. Molecular identification and isolation of the Waxy locus in maize. Cell. 1983 Nov;35(1):225–233. [PubMed]
  • Sullivan TD, Schiefelbein JW, Jr, Nelson OE., Jr Tissue-specific effects of maize bronze gene promoter mutations induced by Ds1 insertion and excision. Dev Genet. 1989;10(6):412–424. [PubMed]
  • Sutton WD, Gerlach WL, Peacock WJ, Schwartz D. Molecular analysis of ds controlling element mutations at the adh1 locus of maize. Science. 1984 Mar 23;223(4642):1265–1268. [PubMed]
  • Vieira J, Messing J. Production of single-stranded plasmid DNA. Methods Enzymol. 1987;153:3–11. [PubMed]
  • Weck E, Courage U, Döring HP, Fedoroff N, Starlinger P. Analysis of sh-m6233, a mutation induced by the transposable element Ds in the sucrose synthase gene of Zea mays. EMBO J. 1984 Aug;3(8):1713–1716. [PMC free article] [PubMed]
  • Wessler SR, Varagona MJ. Molecular basis of mutations at the waxy locus of maize: correlation with the fine structure genetic map. Proc Natl Acad Sci U S A. 1985 Jun;82(12):4177–4181. [PMC free article] [PubMed]
  • Wessler SR, Baran G, Varagona M, Dellaporta SL. Excision of Ds produces waxy proteins with a range of enzymatic activities. EMBO J. 1986 Oct;5(10):2427–2432. [PMC free article] [PubMed]

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