Microfuidic Devices and Open Access Tool for Localized Microinjection and Heart Monitoring of Drosophila Melanogaster

This thesis aims to address the current research gaps associated with the use of Drosophila larvae as an in-vivo model for cardiac toxicity and cardiac gene screening. In objective 1, we have developed a hybrid multi-tasking microfluidic platform that enables desired orientation, reversible immobilization, and localized microinjection of intact Drosophila larvae for recording heart activities upon injection of controlled dosages of different chemicals. In objective 2. we have developed software for in-vivo quantification of essential heartbeat parameters on intact Drosophila larvae. Several image segmentation and signal processing algorithms were developed to detect the heart, extract the heartbeat signal, and quantify heart rate and arrhythmicity index automatically, while other heartbeat parameters were quantified semi-automatically using the M-mode. In objective 3a, we demonstrated the application of our microfluidic device and heartbeat quantification software for investigating the effect of different chemicals (e.g., serotonin and heavy metals) on Drosophila larval heart function. Also, we applied our technology to genetically modified Drosophila larvae to investigate the effect of metal responsive transcription factor (MTF-1) against heavy metals cardiac toxicity (objective 3b).