Ac/Ds prefer to transpose to nearby genes, affording a way to mutagenize those regions of the genome, and by subsequent genetic crosses, remove the Ac that causes new mutants and instability of a Ds mutant. Researchers use mutant phenotypes to discover gene functions. The chromosome breaking property has been shown to come from pairs of closely positioned elements. They also include a class of DNA elements that do not transpose in the presence of the Ac element (Du et al. Genomic analysis of maize show that these elements, which share terminal 11 bp imperfect inverted repeat sequences, have much sequence heterogeneity, both in length and content. The elements have been shown to function in other plants, including tobacco, Arabidopsis, ) and rice. 1983 using insertions of Ac and Ds into the well-studied Waxy(Wx1) gene. The Ac/Ds transposable elements were first isolated and sequenced By Fedoroff et al. Its discovery was based on studying its genetic behavior, i.e., "jumping genes" in maize and published by Barbara McClintock, leading to her 1983 Nobel Prize in Medicine. The phenotypic consequence of Ac/ Ds transposable element includes mosaic colors in kernels and leaves in maize. Both Ac and Ds can also insert into genes, causing mutants that may revert to normal on excision of the element. Ac was initially discovered as enabling a Ds element to break chromosomes.
P element transposon Activator#
The Ac Activator element is autonomous, whereas the Ds Dissociation element requires an Activator element to transpose. Ac/Ds transposable controlling elements was the first transposable element system recognized in maize.
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