In Vivo Imaging of Membrane-Associated Glycans in Developing Zebrafish
Scott T. Laughlin,1*
Jeremy M. Baskin,1*
Sharon L. Amacher,2
Carolyn R. Bertozzi1,2,3,4
Glycans are attractive targets for molecular imaging but have been inaccessible because of their incompatibility with genetically encoded reporters. We demonstrated the noninvasive imaging of glycans in live developing zebrafish, using a chemical reporter strategy. Zebrafish embryos were treated with an unnatural sugar to metabolically label their cell-surface glycans with azides. Subsequently, the embryos were reacted with fluorophore conjugates by means of copper-free click chemistry, enabling the visualization of glycans in vivo at subcellular resolution during development. At 60 hours after fertilization, we observed an increase in de novo glycan biosynthesis in the jaw region, pectoral fins, and olfactory organs. Using a multicolor detection strategy, we performed a spatiotemporal analysis of glycan expression and trafficking and identified patterns that would be undetectable with conventional molecular imaging approaches.
1 Department of Chemistry, University of California, Berkeley, CA 94720, USA.
2 Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
3 Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA.
4 The Molecular Foundry, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
* These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail: crb{at}berkeley.edu
