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Excision and reinsertion of Ac macrotransposons in maize
Dafang Wang1, Chuanhe Yu2, Jianbo Zhang3
1Division of Math and Sciences, Delta State University, Cleveland, MS 38733-0001, USA.
Genetics
|April 26, 2022
Summary
Maize Ac transposons can form Ac::Macrotransposons (MTns) that mobilize large DNA segments. These Ac::MTns exhibit transposition features similar to standard Ac/Ds elements, impacting plant genome evolution.
Area of Science:
- Plant Molecular Biology
- Genetics and Genomics
- Transposable Elements
Background:
- Eukaryotic Macrotransposons (MTns) are formed by two elements flanking host DNA.
- Maize Ac transposons can generate Ac::MTns, but their transposition activity is poorly understood.
- Understanding MTn activity is crucial for comprehending genome evolution and stability.
Purpose of the Study:
- To investigate the transposition activities of Ac::MTns in maize.
- To characterize the features of Ac::MTn transposition and compare them to standard Ac/Ds elements.
- To assess the potential impact of Ac::MTns on plant genome evolution.
Main Methods:
- Studied three Ac::MTns at the maize p1 locus, varying in size from 16 to 22 kb.
- Analyzed Ac::MTn transposition events, including excision footprints and target site duplications.
- Identified MTn-like structures in the maize B73 reference genome and NAM founder lines.
Main Results:
- Identified 10 independent Ac::MTn macrotransposition events with features similar to Ac/Ds transposition.
- Observed genetic linkage between Ac::MTn reinsertion targets and donor sites in 9 out of 10 cases.
- Confirmed historic MTn transposition in diverse maize lines, evidenced by target site duplications.
Conclusions:
- Ac::MTns are capable of mobilizing substantial DNA segments, potentially including full-length plant genes.
- Ac::MTn transposition shares characteristics with standard Ac/Ds elements.
- Ac::MTns have the potential to alter gene colinearity in syntenic regions during plant genome evolution.
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