Characterization of permissivity for hobo-mediated gonadal dysgenesis in Drosophila melanogaster

The hobo transposon is responsible for one of the three hybrid dysgenic sys tems that have been described in Drosophila melanogaster. Most studies on t he hobo dysgenic system have been carried out using the PM system as a refe rence. However, these two systems differ significantly. In particular, seve ral studies have failed to find any correlation between the molecular struc tures of hobo elements, the instability of the transposon and the incidence of gonadal dysgenic (GD) sterility. On the other hand, no study of the abi lity of females to permit hobo activity in their progeny when they are cros sed with males harboring active hobo elements (permissivity) has yet been r eported. In order to investigate the parameters involved in hobo permissivi ty, four E strains were studied with regard to the molecular nature of thei r hobo sequences and the GD sterility induced by a controlled source of hob o transposase. We show that hobo permissivity varies both within and betwee n E strains. Moreover, permissivity decreases with age in E females. Our re sults are discussed with respect to similar phenomena that have been descri bed in relation to the reactivity of the IR dysgenic system.