Progress on Mutator superfamily.

Transposable elements (TEs) are fragments of DNA sequence, which can mobile from one locus to another within a genome, often replication in the process. Occupying the main component of the genome, TEs can affect the structure and function of gene and/or genome in a variety of ways, and play an important role in the evolution of the host. Based on the transposition intermediate, eukaryotic TEs can be divided into two classes. The Mutator superfamily is found in maize (Zea may L.) in the 1970s. As the member of class II elements, Mutator superfamily transposons are found in all eukaryote genomes and contain many families with clearly distinguishable genetic characteristics. In addition, these TEs transpose at high rates and preferentially insert in gene-rich and low-repetitive genomic regions leading to the rapid generation of massive novel mutations, therefore, they are in great use of both forward and reverse genetics researches. In this review, we summarize the classification, structure characteristic, transposition mechanism, insertion preference and TSD sequence and other autonomous MULEs in maize. Moreover, we discuss the problems faced in TEs' research and research directions in the future, with a view to discuss possible breakthroughs, future development directions and significant impacts with colleagues in the related research field..