Advances in multiphoton microscopy for imaging embryos

Multiphoton imaging is a promising approach for addressing current issues in systems biology and high-content investigation of embryonic development. Recent advances in multiphoton microscopy, including light-sheet illumination, optimized laser scanning, adaptive and label-free strategies, open new opportunities for embryo imaging. However, the literature is often unclear about which microscopy technique is most adapted for achieving specific experimental goals. In this review, we describe and discuss the key concepts of imaging speed, imaging depth, photodamage, and nonlinear contrast mechanisms in the context of recent advances in live embryo imaging. We illustrate the potentials of these new imaging approaches with a selection of recent applications in developmental biology.