OCT News 2013 Student Paper Awarded to Jing-gao Zheng from Tsinghua University
Jing-Gao Zheng from Tsinghua University was a winner of the 2013 OCT News Student Paper Award for his submission “Understanding early patterning and polarity of preimplantation mouse embryos with full-field optical coherence tomography.” Below is a summary of his work:
Morphogenetic relationship between early patterning and the polarity formation is of fundamental interest and remains controversial issues in mammalian preimplantation development. Label-free subcellular 3D live imaging technique is very helpful to its related studies.
We have developed a novel system of full-field optical coherence tomography (FF-OCT) for non-invasive 3D sub-cellular live imaging of preimplantation mouse embryos with no need of dye labeling. For the first time, label-free 3D live images were achieved for the mouse embryos at various typical preimplantation stages with a spatial resolution of 0.7 μm and imaging rate of 24 fps. In addition, factors that relate to early patterning and the polarity such as pronuclei in zygote, shapes of zona pellucida, location of second polar body (2PB), and blastocyst axis were quantitatively measured.
For further analysis, we extended our work and made some successful attempts to study the dynamics of developmental processes during mouse preimplantation embryonic lives. We focused our imaging on the event of the first cleavage to investigate 3D spatial morphogenetic relationship between the 2PB and the first cleavage plane. Coupled with 3D quantitative study, we showed that only 25 % of the predicted first cleavage planes, as defined by the apposing plane of two pronuclei passed through the 2PB. Also, only 27% of the real cleavage planes passed through the 2PB. These results suggest that the 2PB is not a convincing spatial cue for the event of the first cleavage.
Our studies demonstrate the feasibility of FF-OCT in providing new insights and potential breakthroughs to the controversial issues of early patterning and polarity in mammalian developmental biology.