Mapping Developmental Mechanics in Drosophila melanogaster with Segmentation and Force Inference

Abstract

Mapping the forces responsible for morphogenetic movements in embryonic Drosophila melanogaster, or the fruit fly, is the focus of this thesis, specifically studying cellular pulsations and laser ablation wounds in the amnioserosa tissue during dorsal closure. First, background topics are explored, including Drosophila structure and development, relevant image processing techniques, mechanical models for tissue, Force Inference (FI) techniques, and an extensive review of existing force measurement techniques from the literature. Next, two systems for cell segmentation, SeedWater Segmenter (SWS) and SWS4D, are presented. Next, laser ablation wounds are characterized in both two and three dimensions using these segmentation tools. Then Force Inference techniques (which infer the underlying stresses from segmented images of tissue) are analyzed, specifically the decay of quality with respect to noise and image rasterization. Last, future force analysis techniques for further extension of force inference are proposed and explored.