Résumé
Introduction : Nutritional symbiosis is crucial for tick growth, with many tick species associating with intracellular bacteria providing them B vitamins, such as Coxiella-like endosymbionts (CLE) or Francisella-like endosymbionts (FLE). Understanding the tissue tropism of these endosymbionts is vital for unraveling the complex relationships between ticks and their microbial partners.Objective : This study examines tissue tropism convergence among CLE and FLE endosymbionts across various soft and hard tick species: Ornithodoros moubata, Ornithodoros maritimus, Dermacentor marginatus, and Dermacentor reticulatus.Material and Methods : Both male and female specimens of these tick species were dissected to analyze their Malpighian tubes, testes or ovaries, salivary glands, midgut, and body. Subsequently, qPCR was used to assess CLE and FLE distribution in organs,Results : Preliminary findings reveal a convergence in tissue tropism, particularly notable in the Malpighian tubes and ovaries, where CLE and FLE endosymbionts were consistently abundant regardless of the tick species.Discussion : Ovarian infection indicates maternal transmission of endosymbionts to developing oocytes, leading to a typically higher quantity of CLE or FLE in females compared to males. The high density in Malpighian tubules supports their nutritional role, potentially in B vitamins biosynthesis.Conclusion : Further research is required to elucidate the significance of these organs in nutritional symbiosis.