A toolkit for mapping cell identities in relation to neighbors reveals conserved patterning of neuromesodermal progenitor populations
Fig 9
Using PRINGLE to analyze patterning in Drosophila embryos.
A: Graphic outlining dorsal-ventral (D-V) patterning boundaries of neuroectoderm and presumptive ventral mesoderm in a late Stage 5 Drosophila embryo. Adapted from [53]. B: Confocal XY and XZ slices of representative embryo labeled by hybridization chain reaction (HCR) for sim, ind, and twist, with the anterior and posterior circumferential domains of salm marking the gnathal and tail regions, respectively [65]. Nuclear membrane marker Lamin labeled by immunofluorescence. White dashed line indicates the section position in the right panel. C: Output of PRINGLE projection from ventral midline after single cell quantification of HCR signal. n = 4. D: The distance from the ventral midline to the twist boundary, ind boundaries, and approximate dorsal midline along anterior-posterior (A-P) axis reveals a seemingly stable twist boundary despite changes in the embryo D-V length. ind domain boundaries appear to converge at the posterior end. E: Directly measuring ind region width shows a linear reduction in width along the A-P axis. F: The linear reduction is maintained when considering width as a relative measure from the twist dorsal boundary to the dorsal midline. G: The location of the twist boundary relative to the ventral and dorsal midlines shifts dorsally along the A-P axis and could explain some but not all the reduction in ind width. H: In terms of distance from the twist boundary, the ventral boundary of ind is maintained at ~35μm but the dorsal boundary shifts ventrally along the A-P axis. E–H: Individual embryos shown by gray lines where left-right patterns were individually calculated and the average taken. Thick line represents the average across embryos. Shaded areas refer to 0.05 and 0.95 confidence intervals (mean ± 1.96 * (σ/(√n)). I: Possible mechanisms to explain the maintenance of the ventral ind boundary with a variable dorsal boundary. Dorsal gradient and induced vnd does not change but 1. the EFG-R active domain restricts and/or 2. the Dpp activity expands to dorsally restrict ind. Data for Fig 9 (C–H): Data file 5, https://doi.org/10.5281/zenodo.15802710.