Vertical Transmission of Is Associated With Host Vitellogenin in .

in host germ lines are essential for their vertical transmission to the next generation. It is unclear how the regulation of host oocyte development influences location and the mechanistic basis of transmission. Here, we investigated whether vitellogenin influences transmission in . increased in density and spread from the anterior tropharium to developing oocytes as ovaries developed. Microscopic observations indicated that invaded ovarioles from the tropharium of its anterior side rather than the pedicel side. utilized the host Vg transovarial transportation system to enter the ovaries and were transmitted from the tropharium into the developing oocytes through nutritive cords. These observations were supported by knocking down the Vg transcript, in which low titers were detected in ovaries and fewer were transmitted into oocytes. Our findings establish a link between the Vg-related mode of transovarial transmission and efficient maternal transmission of .