Fig. 3

Imaging technologies open doors to deeper insights of Drosophila. a Single-photon (confocal) microscopy and multi-photon microscopy visualize samples by exciting the fluorophore and detect the emitted fluorescence. Harmonic generation microscopy, however, does not involve excitation of target molecules for visualization. Second-harmonic generation involves the combination of two photons into one photon without loss of energy. b Laser scanning confocal and spinning disk confocal microscopes illuminate the whole sample and detects epifluorescence, while light-sheet only illuminates the focal plane and detects fluorescence from the perpendicular direction. Adapted with permission from [196]. c Confocal microscopy can achieve excellent imaging quality for imaging tasks that do not require penetration deeper than 100 μm. Figure modified with permission from [197]. d SiMView combines two-photon microscopy with light-sheet microscopy that delivers high imaging speeds and near complete physical coverage of the embryo while reducing photobleaching and phototoxic effects. Scale bar: 50 μm. Figure modified with permission from [94]. e Second-harmonic generation microscopy visualizes muscular architecture and trachea system in detail without fluorophore labeling. Figure modified with permission from [112]. f Third-harmonic generation microscopy was used to visualize lipid trafficking. Scale bar: 50 μm. Figure modified with permission from [113]. g Micro-CT reveals the postmating responses by Drosophila female reproductive tract. Figure modified with permission from [125]