The cartoon shows the migration of Q neuroblasts and their descendants in the L1 larval stage. Image: Institute of BiophysicsPostembryonic development is an essential step during the formation of multicellular organisms after embryonic growth. For example, C. elegans adults are composed of 959 somatic cells, and more than 400 of them are generated in the postembryonic stage. To better understand the process of postembryonic development, scientists need to carry out cell dynamics studies.

High-resolution live imaging has been widely performed in embryos in cell cultures and provides a wealth of information for understanding embryonic development. However, due to the length and complexity of the postembryonic developmental stage and the difficulties in handling live organisms, live-imaging protocols to study postembryonic development are still scarce. Since many processes, including asymmetric cell division and directed cell migration, cannot be easily mimicked in cell culture, the development of a live-imaging system is in urgent need.

Recently, Ou Guangshuo’s group at the Institute of Biophysics, Chinese Academy of Sciences (IBP) developed a live-imaging system to observe the cellular dynamics during C. elegans postembryonic development. They constructed fluorescent transgenic C. elegans strains and conducted time-lapse microscopy analysis. To improve the throughput of imaging, they also developed a C. elegans triple-fluorescence imaging approach with a worm-optimized blue fluorescent protein (TagBFP), green fluorescent protein (GFP) and mCherry.

Together with C. elegans genetics studies, Ou’s group has applied the method successfully in their recent studies, including identification of molecular markers of migrating cells, discovery of a novel asymmetric cell division mechanism, investigation of autophagy gene functions in degrading apoptotic cell corpse and uncovering of the apoptotic mimicry in the midbody clearance.

The novel in vivo live-imaging protocol may provide insights into understanding postembryonic development of organisms and deciphering the molecular mechanisms underlying cellular and developmental processes.

Ou’s group published an article on Nature Protocols introducing their novel fluorescence microscopy system and potential applications and problems as well.

This work was supported by grants from the Ministry of Science and Technology of China, National Natural Science Foundation of China and Chinese Academy of Sciences and the “Thousand Talents Program for Distinguished Young Scholars.”