Comprehensive identification of potentially active transposon-mobility genes in C. elegans genome

Abstract Transposons are the mobile DNA that itself encodes genes for their own mobility. During evolution, transposons accumulated their copies on genomic DNA, whereas many of them lost their mobile activity due to deletion or point mutations on the DNA elements required for their mobility. Here, we focused on the transposon-encoded genes which are directly involved in replication, excision, and integration of transposon DNA, i.e. transposon-mobility genes in the C. elegans genome. Among the 62,773 copies of retro- and DNA transposons in the latest assembly of the C. elegans genome (VC2010), 290 transposon-mobility genes conserved the complete open reading frame (ORF) structure. Among them, only 145 genes conserved the critical amino acids at the catalytic core. In contrast to the huge number of transposon copies in the genome, a limited number of genes encoded potentially functional enzymes for transposon mobility. Our finding indicates that a handful number of transposon copies can autonomously transpose in the C. elegans genome.