Drosophila relics hobo and hobo-MITEs transposons as raw material for new regulatory networks.

Hypermutable strains of Drosophila simulans have been studied for 20 years. Several mutants were isolated and characterized, some of which had phenotypes associated with alteration in development; for example, showing ectopic legs with eyes being expressed in place of antennae. The causal agent of this hypermutability is a non-autonomous hobo-related sequence (hoboVA). Around 100 mobilizable copies of this element are present in the D. simulans genome, and these are likely mobilized by the autonomous and canonical hobo element. We have shown that hoboVA has transcription factor binding sites for the developmental genes, hunchback and even-skipped, and that this transposon is expressed in embryos, following the patterns of these genes. We suggest that hobo and hobo-related elements can be material for the emergence of new regulatory networks.