CC BY
22P-I
Laser optics to uncover mysteries of early development
I.V. Larina1
1Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
Over the last decades, developments in laser-based technologies significantly contributed to multiple areas of biomedicine; however, their application in developmental biology still has a lot of area for exploration. Early mammalian development is of very dynamic and dramatic structural changes, happening on different spatial scales, these ranging from subcellular to the whole organism. Because embryonic development happens deep within the female body, our current understanding of its dynamics is derived from static histological analysis, low-resolution visualizations, and studies of invertebrate models (e.g. sea urchin) and, as a result, do not necessarily represent what really happens. In our pursuit of building a comprehensive understanding of mammalian developmental dynamics in vivo, we took advantage of multiple laser-based technologies and developed a series of imaging methods and protocols combining functional optical coherence tomography (OCT), vital fluorescence reporters, optogenetic control, non-linear microscopy, intravital imaging approaches and mouse models of human developmental defects. We established functional OCT imaging methods providing information about transferring of oocytes/embryos, the contraction of the oviduct muscle, distribution of the frequency of cilia beat, as well as sperm behavior in the ampulla. These new observations revealed never-before-seen dynamic events which contradicted current views in scientific community and suggesting a role for cilia dynamics in the regulation of sperm movements. We are also investigating biomechanical regulation of cardiovascular development and cardiodynamics in live culture. We developed techniques for volumetric heard imaging at cellular resolution, blood flow analysis and 4-D angiography in the heart. These methods were applied to analysis of the pumping mechanism of early hearts and characterization of mutant phenotypes mimicking human congenital heart defects, suggesting regulatory role of heart contractions in cardiogenesis. We are now developing optogenetics to non-invasively manipulate cardiodynamics and second harmonic generation analysis of collagen to define the role of cardiac forces in maintaining mechanical homeostasis. Laser-based technologies have great potential to answer many important biological questions, leading to a better understanding, prevention, and treatment of congenital defects and embryonic failures in humans. Additionally, highly dynamic and diverse developmental processes with variety of challenging and exciting questions provide a great platform for laser physicists and optical engineers to develop new imaging and manipulation methods, pushing forward technological developments in optical engineering.
