Cytotype regulation inDrosophila melanogaster: synergism between telomeric and non-telomericPelements

Abstract

SummaryThe X-linked telomericPelementsTP5andTP6interact synergistically with non-telomericPelements to repress hybrid dysgenesis. In this repression, the telomericPelements exert maternal effects, which, however, are not sufficient to establish synergism with the non-telomericPelements. Once synergism is established, the capacity to repress dysgenesis in the offspring of a cross persists for at least two generations after removing the telomericPelement from the genotype. At the molecular level, synergism between telomeric and non-telomericPelements is correlated with effective elimination ofP-element mRNA in the germ line. Maternally transmitted mutations in the genesaubergine,piwiandSuppressor of variegation 205[Su(var)205] block the establishment of synergism between telomeric and non-telomericPelements, and paternally transmitted mutations inpiwiandSu(var)205disrupt synergism that has already been established. These findings are discussed in terms of a model of cytotype regulation ofPelements based on Piwi-interacting RNAs (piRNAs) that are amplified by cycling between sense and antisense species.