Recent advances in imaging technology have allowed scientists to observe biological dynamics at improved temporal and spatial resolutions. These improvements have facilitated studies directly observing C. elegans embryogenesis at the single cell level while maintaining viability. We have developed an automated analysis pipeline to translate time-lapse image series into extensive, easily interpreted information describing embryonic phenotypes.
C. elegans' invariant lineage provides the opportunity to compare individual cells with the same identity in different embryos. Nuclei are visualized with a histone-GFP fusion protein and imaged each minute to track every cell throughout embryogenesis. We quantified each cell's wild type proliferation, differentiation, and morphogenesis, then compared RNAi-treated embryos to wild type values. With this method we can detect aberrant behavior in single cells the first minute they are abnormal.
To assist our interpretation of abnormalities that disrupt wild type grouping (such as cells of the same lineage or fate) we identify groups of cells that divide synchronously, take on the same fate and/or migrate together. Once we uncover new groups, we can hypothesize which biological process was disrupted to produce the observed reclassification. Using this method we found interesting embryonic RNAi phenotypes for many genes including
par-2,
pie-1,
pop-1,
skn-1 and
mex-5.