Isopod ovary organisation (A) and inferred infection dynamics (B).

<p><b>A</b>: The germarium is composed of oogonia that mature and increase in diameter as they move away from the germarium in the course of ovary maturation The oocytes are encased within two sheets of follicle cells and a layer of connective tissue (dark gray). At spawning muscles compress the ovary to expel the oocytes through the oviduct, which is on the germarium side. <b>B</b>: We propose two non exclusive hypotheses could explain <i>Wolbachia</i> enrichment in the course of oocyte and ovary maturation (Immature, Mature I, Mature II stages): oocyte selection (oocytes uninfected by <i>Wolbachia</i> are preferentially destroyed by oosorption) and/or maturing oocytes acquire <i>Wolbachia</i> secondarily from somatic tissues through follicle cells.