THE CYTOSKELETON AND MORPHOGENESIS OF THE EARLY DROSOPHILA EMBRYO

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