An all-optical approach to modulate and quantitatively analyse embryo morphogenetic movements by using ultrashort laser pulses

Abstract : The regulation of morphogenetic movements that shape an embryo during its development remains a challenging issue in developmental biology, and may in certain cases involve mechanical sensitivity. Addressing this issue requires novel experimental approaches. We show that the combination of femtosecond laser pulse-induced ablation and multiphoton microcopy can be used to modulate and quantify morphogenetic movements in Drosophila embryos. We characterized the effects of focused nanoJoule pulse trains in developing embryos. We used targeted ablations to locally modify the embryo structural integrity and modulate morphogenesis. Femtosecond-pulse induced ablation was combined with nonlinear microscopy based on two-photon-excited fluorescence (2PEF) and third-harmonic generation (THG). Correlation-based analysis of microscopy data allowed us to track the outcome of ablations and to analyze tissue deformations. These experiments provided insight into the interplay between gene expression and tissue deformations in developing embryos.