Author ORCID Identifier:
Date of Graduation
5-2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Cell & Molecular Biology (PhD)
Degree Level
Graduate
Department
Cell & Molecular Biology
Advisor/Mentor
Paré, Adam
Committee Member
Quinn, Kyle
Second Committee Member
Nakanishi, Nagayasu
Third Committee Member
Greene, Nicholas
Fourth Committee Member
Zhuang, Xuan
Keywords
Bioenergetics; Drosophila; Mitochondria; NADH FLIM
Abstract
Mitochondria are dynamic organelles that can fragment or fuse to support different bioenergetic demands and cellular processes, although the role of mitochondrial fission and fusion during embryonic development is not well understood. Fluorescence lifetime imaging (FLIM) of the mitochondrial cofactor NADH can be used to visualize mitochondrial networks and infer aspects of cellular bioenergetics in a label-free manner. We used NADH FLIM to test whether germband cells undergo changes in cellular metabolism during Drosophila convergent extension (CE)––a process in which hundreds of epithelial cells undergo coordinated intercalation to elongate the embryo. Contrary to our expectations, we did not observe significant changes in NADH lifetime or mitochondrial topology during CE, suggesting that germband cells do not need to alter their baseline metabolism to fuel intercalation. Inhibiting mitochondrial fission led to hyper-fused basal networks and a shift towards oxidative phosphorylation, whereas inhibiting fusion led to hyper-fragmented apical networks and a shift towards glycolysis. Inhibiting either mitochondrial fission or fusion increased cell intercalation errors during CE, suggesting that a precise network topology is required for proper tissue elongation. These defects in fission-impaired embryos could be rescued by knocking down ROS scavengers, suggesting that one of the roles of mitochondria during CE is to create a ROS-rich environment to support cell motility. This study demonstrates the utility of NADH FLIM for visualizing mitochondria and characterizing bioenergetics during development in live embryos, and this technique should be broadly applicable to many other systems.
Citation
Espana Pena, M. (2026). NADH FLIM Reveals Cellular Bioenergetics and Mitochondrial Morphology During Drosophila Convergent Extension. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6220
