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Updated: Apr 10, 2026
High-Resolution C. elegans Imaging Across All Larval Stages
Published on: May 23, 2025
Morphologically defined sub-stages of C. elegans vulval development in the fourth larval stage
Darren Z L Mok1, Paul W Sternberg2, Takao Inoue3,4
1Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Blk MD7, #02-06, Singapore, 117597, Singapore.
Background:
During the fourth larval (L4) stage, vulval cells of C. elegans undergo extensive morphogenesis accompanied by changes in gene expression. This phase of vulval development, occurring after the well-studied induction of vulval cells, is not well understood but is potentially a useful context in which to study how a complex temporal sequence of events is regulated during development. However, a system for precisely describing different phases of vulval development in the L4 stage has been lacking.
Results:
We defined ten sub-stages of L4 based on morphological criteria as observed using Nomarski microscopy (L4.0 ~ L4.9). Precise timing of each sub-stage at 20 °C was determined. We also re-examined the timing of expression for several gene expression markers, and correlated the sub-stages with the timing of other developmental events in the vulva and the uterus.
Conclusions:
This scheme allows the developmental timing of an L4 individual to be determined at approximately one-hour resolution without the need to resort to time course experiments. These well-defined developmental stages will enable more precise description of gene expression and other developmental events.
