A transcript identified by MuA of maize is associated with Mutator activity

Area of Science:

• Plant genetics
• Molecular biology
• Transposable elements

Background:

• The Mutator system in maize is a source of genetic instability.
• Understanding the molecular basis of Mutator activity is crucial for maize genetics.

Purpose of the Study:

• To clone and characterize a novel Mu element from maize.
• To investigate the relationship between the cloned element and Mutator activity.

Main Methods:

• Cloning of the MuA element based on homology to Mu1.
• Restriction fragment analysis and hybridization studies.
• Northern blot analysis to detect transcripts.

Main Results:

• MuA is a large Mu element (5.5 kb) with unique flanking duplications.
• MuA sequences cosegregate with Mutator activity.
• A 3.5 kb transcript associated with MuA is present in active Mutator lines and absent in inactive lines.

Conclusions:

• The 3.5 kb transcript is likely produced by an autonomous Mu element conferring Mutator activity.
• MuA is a strong candidate for an autonomous or regulatory element within the Mu family.