Figure 1. Using Single-Cell Transcript Counting to Study the Control of
mab-5 Expression (A) Schematic representation of the activation of MAB-5 expression in QL in response to the posterior- to-anterior gradient of EGL-20/Wnt. (B) Model of Wnt signaling based on published studies. Question marks and gray edges indicate lack of definitive evidence. (C) Final position of QL descendants in wild-type and various Frizzled loss-of-function mutants. Unless otherwise noted, compound mutants carry the same alleles as single mutants. (D) Detection of
mab-5 transcripts using smFISH over the course of QL migration. Upper: QL at different stages of its migration. V5 is a stationary cell used as spatial reference. Lower: smFISH staining of
mab-5 transcripts in the same cells as shown above. Yellow arrowheads: single
mab-5 transcripts; white arrowheads: transcription centers in the nucleus. Scale bar represents 2.5 mm. (E)
mab-5 transcription dynamics in single QL neuroblasts in wild-type animals. Upper: normalized total MD for worms collected at different time points after hatching. Black dots mark the mean, and blue bars span 2.5-97.5 percentiles. Lower: number of
mab-5 transcripts per cell plotted against MD. The histogram to the right is generated using data points to the left with MD > 8. Black lines are generated by fitting to a sigmoidal function. Red curves are generated by fitting with two Gaussian distributions. (F) mCherry transcription dynamics in the POPTOP strain.