Xiaoyu Shi, Ph.D.
Ph.D. University of California, Davis
Postdoc University of California, San Francisco
Research Areas: Structural Biology, Super-Resolution Microscopy, Systems Biology, Cell Signaling, Cilia Biology, Developmental Biology, Bioimaging, Biophysics, Cell Biology.
Cells are the essential building blocks of life. They participate in the development and function of organs at all spatial scales – from molecular signaling to tissue patterning. The mission of Shi’s lab is to elucidate how cells drive developmental mechanisms across all scales. To answer these questions, we leverage super-resolution microscopy and chemical synthesis to develop novel cutting-edge imaging and multiomics methods and apply these methods to study the following specific topics:
I. How cellular machineries are organized at the molecular scale?
Seeing is believing. A major objective of our research program is to directly visualize how cells organize proteins, RNA, and DNA in space and time. We have developed a series of super-resolution microscopy methods to dissect the architecture of cellular structures at the molecular resolution, and with high labeling efficiency, brightness, and detection sensitivity. We are particularly interested in the structure-function relationships of the nuclear lamina, chromatin, cytoplasmic vesicles, and cellular protrusions called cilia.
Methods: Expansion Microscopy (ExM), Stochastic Optical Reconstruction Microscopy (STORM), Structured Illumination Microscopy (SIM), Airyscan Microscopy
II. How do primary cilia mediate Hedgehog signaling?
Hedgehog signaling pathway is the key signaling regulator of embryonic tissue patterning and adult tissue homeostasis. Defects in Hedgehog signaling can cause a multitude of developmental diseases, such as a congenital heart disease, and cancers, such as melanoma. Primary cilia, specialized protrusions on cell membrane, have an essential role in Hedgehog signaling in mammals. Our research objective is to determine the molecular mechanisms that underlie the regulation of Hedgehog signaling by primary cilia. Empowered by fast imaging and endogenous labeling technologies, we are able to directly watch and analyze the behavior of signaling and transporter molecules in action.
Methods: Live-cell single-particle tracking, Light-sheet microscopy, Total Internal Reflection Fluorescence Microscopy (TIRF), photoconversion
III. How single-cell multiomic data are organized at the spatial scale?
Over the last few years we are witnessing rapid advances in the fields of single-cell transcriptomics, genomics and proteomics. However, most tissues and organs are solid, with cells encased within a complex extracellular matrix network. Studying single cells from solid tissues usually requires their mechanical and enzymatic disaggregation. As a result, the positional information is lost, which is otherwise essential for proper understanding of how cells cooperate in tissues. We take optical and chemical approaches to develop novel, spatially-resolved multiomic methods, which isolate cells without homogenization, enable cell phenotyping with super resolution, and allow multiomics in the same single cells. This novel platform will significantly advance our knowledge on how cell phenotypes are maintained in native tissue and become perturbed in disease.
- X. Shi*, Q. Li*, Z. Dai, A.A. Tran, S. Feng, A.D. Ramirez, Z. Lin, X. Wang, T.T. Chow, I.B. Seiple#, B. Huang#, Label-retention expansion microscopy, submitted, (2019) [bioRxiv link]
- X. Shi, G. Garcia, Y. Wang, J. Reiter, B. Huang, Alignment of super-resolution images for semi-flexible structures in 3D, PLoS One 0212735 (2019). [link]
- T.T. Chow, X. Shi, J.H. Wei, J. Guan, G. Stadler, B. Huang, E. Blackburn, Local enrichment of HP1alpha at telomeres alters their structure and regulation of telomere protection, Nature Communications 9, 3583 (2018). [link]
- X. Shi*, G. Garcia*, J.C. Van De Weghe, R. McGorty, G.J. Pazour, D. Doherty, B. Huang#, J.F. Reiter#, Super-resolution microscopy reveals that disruption of ciliary transition zone architecture is a cause of Joubert syndrome, Nature Cell Biology 19, 1178 (2017). [link]
- J. Guan, H. Liu, X. Shi, S. Feng, B. Huang, Tracking multiple genomic elements using correlative CRISPR imaging and sequential DNA FISH, Biophysical Journal 112,1077 (2017). [link]
** New and Notable**
- X. Shi, H. Gao, Q.-Z. Yin, Y.-C. Chang, R.C. Wiens, W. M. Jackson, C.Y. Ng, Branching ratio measurements of the predissociation of 12C16O by time-slice velocity-map ion imaging in the energy region from 106,250 to 107,800 cm-1, Journal of Physical Chemistry A 122, 8136, (2018).
- X. Shi, Q.-Z. Yin, H. Gao, Y.C. Chang, W.M. Jackson, R. Wiensand C.Y. Ng, A Predissociation Branching Ratio Comparison of CO and N2: Implications for Oxygen Nitrogen Isotope Evolution in the Early Solar System, Astrophysical Journal850, 48 (2017). [link]