Repair of endonuclease- and transposon-induced DNA double strand breaks by host factors in Arabidopsis /

by Li, Zhuying.

Abstract (Summary)
The maize Ac/Ds transposable elements are members of the hAT transposon family. Ac/Ds transpose in diverse species and via a mechanism similar to that involved in V(D)J recombination. Here, we studied the repair of Ds transposition-induced hairpins by host factors in Arabidopsis. The results indicate that AtKu could position hairpin-opening to sites close to the hairpin apex, In the absence of AtMre11 or AtKu70, repair junctions have a higher frequency of small deletions (3-10bp) and larger deletions (11-50bp), respectively. Comparison of the repair of l-Scel- and Ds-induced DSB indicates that Ac transposase could influence Ds-induced DSB repair. In addition, analysis of I-Scel-induced DSB repair indicates that both AtKu70 and AtMre11 are critical for non-homologous end joining (NHEJ); AtKu70, but not AtMre11 affects its fidelity. In these respects, NHEJ in Arabidopsis resembles that in S. cerevisiae. However, in Arabidopsis, the repair junctions are error-prone, and microhomology-mediated end joining is not affected by AtKu70. Hence, its junction patterns are similar to those in mammals. These results indicate the dynamics of DSB repair among different organisms.
Bibliographical Information:


School:Iowa State University

School Location:USA - Iowa

Source Type:Master's Thesis



Date of Publication:

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