Penetrating view of nano-structures in Aleochara verna spermatheca and flagellum by hard X-ray microscopy

A penetrating view of the three-dimensional nano-structure of female spermatheca and male flagellum in the species Aleochara verna is obtained with 100-nm resolution using a hard X-ray microscope, which provides a fast noninvasive imaging technology for insect morphology. Through introducing Zernike phase contrast and heavy metal staining, images taken at 8 keV displayed sufficient contrast for observing nanoscale fine structures, such as the spermatheca cochleate duct and the subapex of the flagellum, which have some implications for the study of the sperm transfer process and genital evolution in insects. This work shows that both the spatial resolution and the contrast characteristic of hard X-ray microscope are quite promising for insect morphology studies, in particularly, provide an attractive alternative to destructive techniques for internal soft tissues.