"9 + 0" immotile spermatozoa in an infertile man.

In this paper the peculiar case of an infertile man, possessing only normally shaped, but stiff and immotile spermatozoa is described. All the sperm are conventionally structured, with the constant characteristic of the absence of central tubules and projections forming the so-called central sheath. Electrophoretic analysis of the high molecular weight polypeptide chains attributed to dyneins shows the constant absence of one chain. The importance of the central structure, usually belonging to the "9 + 2" model spermatozoa, and the possible localization of a dynein chain in this region are discussed.