The effect of antidynein 1 serum on the movement of reactivated sea urchin sperm.

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Abstract
Rabbit antiserum prepared against an ATPase-containing tryptic fragment of dynein by Ogawa and Mohri (1975) specifically inhibited the ATPase activity of dynein 1 and not that of dynein 2. Varying amounts of this antidynein 1 serum were added to demembranated [Colobocentrotus atratus] sperm while they were swimming in reactivating solution containing 1 mM ATP. The sperm containued to form regularly propagated flagellar bending waves, but the beat frequency decreased gradually with time, the greater part of the change occurring in the first 15 min. The beat frequency after 1 h was a function of the amount of antiserum used, and could be as low as 1 Hz. The waveforms of the treated sperm resembled those of normal reactivated sperm except that the bend angles of both the principal and reverse bends were larger in the proximal portion of the flagellum. The ATPase activity and corresponding beat frequency of sperm pretreated with varying amounts of antidynein 1 serum for 15 min at 0.degree. C and then diluted were both decreased as a function of the amount of antiserum added, the ATPase activity decreasing more steeply than the frequency. The ATPase activity of homogenized, nonmotile sperm decreased upon pretreatment with antiserum, but the percentage decrease was less than for motile sperm. For moderate to low concentrations of antiserum, the rates of reaction with motile and with rigor sperm were almost identical. Antidynein 1 seems to inhibit the functioning of the dynein arms, probably by blocking the ATPase sites of the dynein 1.