Visualizing every hepatocyte in an intact adult vertebrate liver｜ Institute of Cellular and Organismic Biology, Academia Sinica

Visualizing every hepatocyte in an intact adult vertebrate liver

Vertebrate organs undergo massive growth during the post-embryonic period. Yet, our    understanding of how this organ-wide process is organized at single-cell resolution has been limited by an inability to monitor individual cells of different types throughout intact adult organs. Here we establish an integrated workflow of whole adult-organ expansion microscopy (WAO-ExM) that enables in toto single-cell-resolved visualization of every hepatocyte within a complete adult vertebrate liver. We found that an intact adult liver spanning ~5 mm thickness had an average of 1,265,206 hepatocytes. Integration of lineage tracing with WAO-ExM revealed that cell number increases were driven by a few hepatocytes undergoing drastic clonal expansion at the whole-organ scale. Disruption of extracellular matrix laminins decoupled liver shaping from total cell number increases, suggesting independent regulatory control of tissue architecture and cell proliferation. Altogether, these findings bridge micrometer-scale cell behaviors with centimeter-scale organ growth, and establish a generalizable platform for adult vertebrate organs to be fully resolved at bona fide single-cell resolution.

Reference: Roan HY, Tian XJ, Chu WC, Lee CM, Chen H, Santoso F, Wang CH, Liu YH, Kumar U, Hsiao HY, Yuh CH, Chen BC*, Chen CH*. “Whole-organ single-cell mapping defines growth dynamics and clonal organization in developing and adult zebrafish livers” PLoS Biology, https://doi.org/10.1371/journal.pbio.3004007

Whole Adult-Organ Expansion Microscopy (WAO-ExM) image of an expanded adult zebrafish liver. The lower-right inset shows a magnified view highlighting the subcellular resolution achieved by WAO-ExM.