Localized ERK activation can trigger mitotic entry in Drosophila embryo.
Movie shows mitotic waves initiated from the center of optoSOS embryo. optoSOS allows for ectopic activation of the RAS/ERK pathway in response to optical stimulation. The Red box indicates the illuminated region, where ERK signaling is activated. Histone-mIFP is used to visualize the nuclei. Interphase and M-phase nuclei are marked by yellow and blue, respectively. Scale bar = 50 µm. Taken from Yang L et al. 2024 (Dev Cell).
Deformation of the hindgut at the onset of gastrulation in Drosophila embryo.
The embryo is patterned with genes that specify cell fates and instruct behaviors. At the onset of gastrulation, cells within these genetically patterned domains change shape and rearrange to generate in- and out-of-plane deformations, behaving as active materials. Here, we show a surface generated from nuclei within a tissue that has been presumed to be passive, the hindgut primordium. We use this tissue to study the interactions between active and passive tissues, the role of embryonic geometry, and mechanics in morphogenesis.