The cytoplasmic matrix of the human spermatozoon: cross-filaments link the various cell components.
This transmission electron microscopic study demonstrated a periodic arrangement of short cross-filaments in all the cytoplasmic layers of the human spermatozoon. These filaments were connected with adjacent cellular components (of the same type or not) thus appearing to link the sperm structures to one another. The filaments of the peripheral cytoplasm, those of the perinuclear space and those between the cytoskeletal structures of the flagellum were 3 to 5 nm, 7 to 9 nm and 2 to 4 nm wide respectively. These cross-links displayed a 14 to 20 nm periodicity and measured 6 to 35 nm in length, depending upon their location. They were associated with electron dense patches on the outer acrosomal membrane. Plasma membrane swelling was associated with a disruption of the cortical filaments on the inside surface of the membrane. This suggested a relation between the normal morphology of the plasmalemma and the cross-filaments. In altered sperm heads, a particular modification of the perinuclear space was found consisting of an aggregation of the cross-filaments into repeated bundles. Many of the morphological characteristics of these cross-filaments could be compared to similar cytoskeletal structures as known in somatic cells. The data of this study suggest that this filamentous network may play an essential role in the maintenance of the topographical relations between the various organelles which may be especially necessary due to the kinematics of this cell.
D002462:Cell Membrane / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D009940:Organoids / Q000648:ultrastructure; D013077:Sperm Head / Q000648:ultrastructure; D013082:Sperm Tail / Q000648:ultrastructure; D013094:Spermatozoa / Q000648:ultrastructure*