The intracellular positioning of the nucleus has gained substantial interest among biologists due its relevance in cell cycle, differentiation, migration, and polarity. Abnormal positioning has been related to cell and tissue function deficiency and severe defects in embryogenesis. Membrane linkers and cytoskeletal and molecular motor dynamics are essential factors for nuclear movement. However, understanding the coordination and the quantification of force generating elements for nuclear positioning are current challenges. In this project, we investigate time-resolved nuclear distribution starting at the earliest stage of Drosophila embryo development to understand causality and regulation of nuclear positioning. We infer on how predefined external factors (e.g. neighbor nuclei, cytoplasmic volume, geometry) influence the dynamics of the cytoskeletal machinery surrounding a nucleus, with focus on microtubules, actin, associated molecular motors and linking proteins.

Fertilization is a vital process as it lies at the heart of animal reproduction. Because fertilization happens deep inside the egg, which is carried inside a living organism and filled with diffractive yolk, time-lapse light microscopy has been challenging. Most of the existing knowledge on insect fertilization was obtained from the analysis of fixed and immunostained eggs. Thus, we lack important temporal and dynamic information of molecular and cellular processes such as chromosome and cytoskeletal dynamics. The main goal of this project is to develop a reconstitution assay of Drosophila melanogaster fertilization enabling live microscopy. Our assay will open new avenues to study chromosomal dynamics during fertilization enabling more detailed insight, for example, into bacteria transmission and cytoplasmic incompatibility (CI).