The Mu Transposable Elements of Maize: Evidence for Transposition and Copy Number Regulation during Development
AUTOR(ES)
Alleman, Mary
RESUMO
The Mu transposon of maize exists in a highly mutagenic strain called Robertson's Mutator. Plants of this strain contain 10–50 copies of the Mu element, whereas most maize strains and other plants have none. When Mutator plants are crossed to plants of the inbred line 1S2P, which does not have copies of Mu, the progeny plants have approximately the same number of Mu sequences as did their Mutator parent. Approximately one-half of these copies have segregated from their parent and one-half have arisen by transposition and are integrated into new positions in the genome. This maintenance of copy number can be accounted for by an extremely high rate of transposition of the Mu elements (10–15 transpositions per gamete per generation). When Mutator plants are self-pollinated, the progeny double their Mu copy number in the first generation, but maintain a constant number of Mu sequences with subsequent self-pollinations. Transposition of Mu and the events that lead to copy number maintenance occur very late in the development of the germ cells but before fertilization. A larger version of the Mu element transposes but is not necessary for transposition of the Mu sequences. The progeny of crosses with a Mutator plant occasionally lack Mutator activity; these strains retain copies of the Mu element, but these elements no longer transpose.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1202684Documentos Relacionados
- Mu1-Related Transposable Elements of Maize Preferentially Insert into Low Copy Number DNA
- Molecular model for the transposition and replication of bacteriophage Mu and other transposable elements.
- Genetic Characterization of the Mutator System in Maize: Behavior and Regulation of Mu Transposons in a Minimal Line
- Expression and Post-Transcriptional Regulation of Maize Transposable Element MuDR and Its Derivatives
- The Ac and Uq Transposable Element Systems in Maize: Interactions among Components