THE ULTRASTRUCTURE OF THE EJACULATED FOWL SPERMATOZOON

Open Access
Publisher Website
Google Scholar
Abstract
The ultrastructure of the fowl spermatozoon differs in several ways from that of the mammalian spermatozoon, and the probable implications of the findings for the difficult problem of storing fowl semen in vitro are discussed. The acrosome has a simpler structure than in the mammal and does not spread down over the membrane of the head. Greater structural differences occur in the tail region, the middle‐piece of which is particularly prone to deteriorate in vitro. The eleven axial (tail) fibres arise from a centriolar complex in the neck region of the spermatozoon; at this level, and more distally in the wall of the distal centriole, they resemble microtubules in cross‐section. The nine outer ones show the triplet tubule structure typical of cell centrioles. The complex ‘endoskeleton’ of segmented columns in the neck, and outermost coarse fibres in the middle‐piece and principal‐piece of the tail, are absent in the fowl. In the distal part of the middle‐piece the tail fibres separate; here and in the principal‐piece they show the typical doublet structure seen in the tail of mammalian spermatozoa, cilia and flagella. The principal‐piece of the fowl spermatozoon is composed solely of a continuous sheath of amorphous material surrounding the eleven axial fibres; the sheath is absent from the distal end of the tail. In contrast with the situation in the mammal, no segmentation of this material is evident and no continuous lateral columns are present in the tail.

This publication has 0 references indexed in Scilit: