THE CYTOSKELETON AND MORPHOGENESIS OF THE EARLY DROSOPHILA EMBRYO

Drosophila embryogenesis begins with thirteen mitotic divisions that occur without cytokinesis. During these syncytial divisions, a series of stereotyped nuclear movements produce a syncytial blastoderm embryo that is characterized by a uniform monolayer of cortical nuclei. Inhibitor studies indicate that actin filaments and microtubules mediate the coordinated nuclear movements of the syncytial stages of embryogenesis. Recent genetic and cytological analyses provide new insight into the functions of specific microtubule and actin filament arrays in organizing the syncytial embryo, and these may lead to the identification of novel regulatory and structural components of the cytoskeleton.