In addition, specific staining was observed in association with manchettes, microtubule-rich structures previously shown, using a different antibody, to contain an isoform of cytoplasmic dynein. Finally, staining in Sertoli cells occurred in regions known to be rich in microtubules and thought to be sites of active microtubule-based organelle (endoplasmic reticulum, mitochondria, vesicles) motility during spermatogenesis. proventil inhaler
Although the antibody reacted strongly with a band at the molecular size for the intermediate chain of cytoplasmic dynein on immunoblots, it did react weakly with two minor bands of lower molecular size that could not be convincingly accounted for in normal mouse IgG controls. These bands were of a lower molecular mass than the 67-kDa isoform of the intermediate chain of cytoplasmic dynein known to be present in mammalian flagella, which has been demonstrated to cross-react on blots with the 74.1 antibody. These could be proteolytic fragments of IC74. Alternatively, these minor antigens may be responsible for the enigmatic staining associated within dorsal regions of the spermatid head—alocationinwhich microtubules ere not known to be present.