BmPMFBP1 is essential for eupyrene sperm migration to female reproductive tracts.

(A) Morphologies of internal structure of ejaculatory seminalis of unmated WT and ΔBmPMFBP1 males. (B, C) The smear of the ejaculatory seminalis (ES). (D) Morphologies and internal structure of bursa copulatrix in females mated with WT and ΔBmPMFBP1 males. (E, F) The smear of the bursa copulatrix (BC) (G) Morphologies and internal structure of spermatheca in females mated with WT and ΔBmPMFBP1 males. The green arrows indicate the spermatheca. (H, I) The smear of the spermatheca (Sp). The yellow arrows indicated the eupyrene sperm/sperm bundles, the red arrows indicated the apyrene sperm. Paraffin-embedded sections were stained with hematoxylin, eosin, and Hoechst 33258.