Ultrastructural changes in the sperm-tail of zinc-deficient rats

Young male rats were fed a diet containing less than 1 mg per kg zinc for 40 days and developed severe atrophy of the seminiferous tubules. The tails of the spermatids and spermatozoa within these tubules were often malformed. The most common abnormality was the absence of one or more of the microtubular components of the axonemes. Pronounced abnormalities of the axoneme were usually accompanied by disruption of the sheath of accessory fibres. These changes are compared with those arising from other experimental treatments and their aetiology is discussed in relation to the possible involvement of zinc in the assembly of microtubules.