Résumé
Parasitic flatworms includemore than 20,000 species that are classically hermaphrodites. Among them, the roughly hundred species of Schistosomatidae are intriguing because they are gonochoric. Schistosomes are responsible of the secondmost important parasitic disease worldwide, and eggs are themain cause of the inflammatory symptoms. Thus, studying the sexual reproductionmechanisms of schistosomes is of particular interest for drug development. Schistosome’s sex is genetically determined by the presence of sex chromosomes: ZZ inmales or ZW in females. There is, however, no phenotypic dimorphismin the larval stages: sexual dimorphismappears only in the vertebrate host. In order to understand the molecularmechanisms underlying phenotypic sexual dimorphism,we performed a transcriptome analysis (RNA-Seq) in five different stages of the parasite lifecycle as well as a chromatin status analysis (ChIP-Seq) in the non-differentiated stage cercariae and in the adult differentiated stage, for males and females separately. Our work presents evidence that sexual differentiation in S.mansoni is accompanied by distinctmale and female transcriptional landscapes of known players of the host-parasite crosstalk, developmental pathways and epigenetic regulators. Our sex-comparative approach provides therefore new potential therapeutic targets to affect development and sexual reproduction of parasite.