Ultrastructure of the nebenkern during spermatogenesis in the praying mantidHierodula membranacea

Spermatogenesis leads to the formation of functional sperm cells. Here we have applied high-pressure freezing in combination with transmission electron microscopy (TEM) to study the ultrastructure of sperm development in subadult males of the praying mantid Hierodula membranacea . We show the ultrastructure of different stages of sperm development in this species. In addition, we have applied serial-section electron tomography of the nebenkern to demonstrate in three dimensions (3D) that this organelle is composed of two interwoven segments that are connected by a zipper-like structure at opposing positions. Our approach will enable further ultrastructural analyses of the nebenkern also in other organisms.