Fig. 3. The length of the cellular protrusions of macrophages depends on dizzy. Cellular protrusions per macrophage have been measured for the given genotypes in fixed and immunostained embryos beneath the dorsolateral epidermis at stage 14. In dizzy mutants and in embryos expressing ds.dizzy in macrophages the average length of cellular protrusions per cell is about half of the length seen in wild-type macrophages. Overexpression of dizzy (dizzy^h.EP) or of dominant-active Rap1^V12 in macrophages leads to an increase of total length per cell by a factor of about four and three, respectively. As the protrusions of macrophages in these embryos span from cell body to cell body, standard deviations are here based on the lengths of individual protrusions rather than on the overall length per cell. The increase in protrusion length depends in both cases, dizzy^h.EP and Rap1^V12, on the zygotic expression of ßPS integrin mys. In zygotic mys mutants the length per cell is similar to wild-type even when dizzy or dominant-active Rap1^V12 is expressed in the macrophages.