Morphology of the "spindle-shaped body" in the developing tail of human spermatids.
At the beginning of the late cap phase of the normal differentiation of human spermatids, a unique structure, the "spindle shaped body", occupies part of the future middle-piece. This spindle-shaped body was followed throughout its development, and its functional relationahip to the formation of the fibrous sheath is discussed. The spindle-shaped body disappears when the fibrous sheath is completed and the annulus moves down, giving rise to the middle-piece.
D000328:Adult; D002467:Cell Nucleus / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008870:Microtubules / Q000648:ultrastructure*; D008875:Middle Aged; D013082:Sperm Tail / Q000648:ultrastructure; D013087:Spermatids / Q000648:ultrastructure*; D013091:Spermatogenesis; D013094:Spermatozoa / Q000648:ultrastructure*