Sectorial mutagenesis by transposable elements

Transposable elements (TEs) generate insertions and cause other mutations i n the genomic DNA. It is proposed that during co-evolution between TEs and eukaryotic genomes, an optimal path of the insertion mutagenesis is determi ned by the surviving TEs. These TEs can become semi-permanently established , chromatin-regulated 'source' or 'mutator genes', responsible for targetin g insertion mutations to specific chromosomal regions. Such mutations can m anifest themselves in non-random distribution patterns of interspersed repe ats in eukaryotic chromosomes. In this paper we discuss specific models, ex amples and implications of optimized mutagenesis in eukaryotes.