Formation of a spermatozoon from a diploid spermato-gonial progenitor cell involves reduction of the chromosomal content during meiosis and several major structural changes to the cell during spermatid differentiation. These changes, which include compaction of the chromatin, changes in nuclear morphology, development of the acro-some, and formation of a flagellum, require the expression of testis-specific genes and the formation of germ cell-specific organelles. One such organelle, a specialized microtubule array called the manchette, materializes in the differentiating spermatid and is transiently associated with the spermatid nucleus for several days. asthma inhalers
Formation of the manchette is first detected in step 8 spermatids as a ‘‘grass-skirt” of microtubules emanating from a nuclear ring of rodlike material on the caudal surface of the nuclear envelope. In steps 9-16, the manchette extends caudally around the developing flagellum although never reaching its end. The manchette is attached to the nucleus at distinct angles, reflecting changes in nuclear shape. The manchette is disassembled in elongated spermatids before they are released from their Sertoli cell associations into the lumen of the seminiferous tubule.