IFA and TEM observations show the infected ovariole sheath.

IFA observations show the adhesion of N. bombycis to ovariole sheath (A, B) and proliferation (C). (D-E) TEM demonstrate the parasite proliferation in ovariole sheath. The yellow dashed lines indicate the boundaries of ovariole sheath; white dashed lines indicate the infected hemolymph cells; red dashed lines indicate lipid droplet in the cell. Arrowhead, mature spores; arrow, parasites in proliferation; spores were stained using FB28 (blue); proliferative parasites was labeled with anti-N. bombycis polyclonal antibody and conjugated with Alexa Fluor 488 (green); nuclei were stained using PI (red). N, nucleus; Ov, ovariole; OS, ovariole sheath; LD, lipid droplet; FC, follicular cell; O, oocyte; NC, nurse cell.

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