The blockade of pigment displacement in swordtail erythrophores by microinjection of antiactin antibody

When antiactin antibody produced against carp skeletal muscle actins was microinjected into monolayer‐cultured swordtail erythrophores, pigment displacement was almost completely blocked. Moreover, the injected antibody was equally effective at blocking the aggregation of dispersed pigment and the dispersion of aggregated pigment. If antibody saturated with carp actins was microinjected, no such blockade occurred. Microinjection of phalloidin or DNase I into these cells brought about an incomplete inhibition of their pigment displacement. These two drugs tended to inhibit pigment dispersion more than aggregation, suggesting that actins are differently involved in the two phases of pigment movement. The results all indicate that actins are functional elements in the pigment displacement of swordtail erythrophores, and that G‐F transformations of these molecules play little or no role in pigment aggregation, but are implicated in some way in dispersion.