RT Journal Article SR Electronic T1 Dynamic Interactions Between the Genome and an Endogenous Retrovirus: Tirant in Drosophila simulans Wild-Type Strains JF G3: Genes|Genomes|Genetics FD Genetics Society of America SP 855 OP 865 DO 10.1534/g3.118.200789 VO 9 IS 3 A1 Fablet, Marie A1 Jacquet, Angelo A1 Rebollo, Rita A1 Haudry, Annabelle A1 Rey, Carine A1 Salces-Ortiz, Judit A1 Bajad, Prajakta A1 Burlet, Nelly A1 Jantsch, Michael F. A1 Guerreiro, Maria Pilar GarcĂ­a A1 Vieira, Cristina YR 2019 UL http://www.g3journal.org/content/9/3/855.abstract AB All genomes contain repeated sequences that are known as transposable elements (TEs). Among these are endogenous retroviruses (ERVs), which are sequences similar to retroviruses and are transmitted across generations from parent to progeny. These sequences are controlled in genomes through epigenetic mechanisms. At the center of the epigenetic control of TEs are small interfering RNAs of the piRNA class, which trigger heterochromatinization of TE sequences. The tirant ERV of Drosophila simulans displays intra-specific variability in copy numbers, insertion sites, and transcription levels, providing us with a well-suited model to study the dynamic relationship between a TE family and the host genome through epigenetic mechanisms. We show that tirant transcript amounts and piRNA amounts are positively correlated in ovaries in normal conditions, unlike what was previously described following divergent crosses. In addition, we describe tirant insertion polymorphism in the genomes of three D. simulans wild-type strains, which reveals a limited number of insertions that may be associated with gene transcript level changes through heterochromatin spreading and have phenotypic impacts. Taken together, our results participate in the understanding of the equilibrium between the host genome and its TEs.