DROSOPHILA-MELANOGASTER SYNCYTIAL NUCLEAR DIVISIONS ARE PATTERNED - TIME-LAPSE IMAGES, HYPOTHESIS AND COMPUTATIONAL EVIDENCE

Time-lapse microscopy of biological systems has provided new and excit ing information about the dynamics of cellular and developmental event s. However, these events are often complex and difficult to analyze. T his paper describes a study in which computation was indispensable for formulating and evaluating a cellular/developmental hypothesis direct ly from observations of time-lapse fluorescence images. Previous analy ses of time-lapse microscopy sequences of Drosophila melanogaster embr yonic syncytial nuclear cycles 10-13, when the nuclei form an evenly s paced monolayer at the surface of the embryo, have failed to identify any pattern in these divisions. However, computational analysis of the data has provided evidence that the direction of syncytial nuclear mi tosis is not random, but is clearly influenced by the relative positio ns of neighboring nuclei. An approximate law governing mitotic directi on that is based on a scheme that compromises among ''votes'' made by neighboring nuclei is introduced. (C) 1995 Academic Press Limited