Small RNA-Mediated De Novo Silencing of Ac/Ds Transposons Is Initiated by Alternative Transposition in Maize.

ABSTRACT: Although transposable elements (TEs) comprise a major fraction of many higher eukaryotic genomes, most TEs are silenced by host defense mechanisms. The means by which otherwise active TEs are recognized and silenced remains poorly understood. Here we analyzed two independent cases of spontaneous silencing of the active maize Ac/Ds transposon system. This silencing is initiated by alternative transposition, a type of aberrant transposition event that engages the termini of two nearby separate TEs. Alternative transposition during DNA replication can generate Composite Insertions that contain inverted duplications of the transposon sequences. We show that the inverted duplications of two Composite Insertions are transcribed to produce double-stranded RNAs that trigger the production o

SUBMITTER: Wang D 

PROVIDER: S-EPMC7268987 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature