Résumé
Phmamm-16Organism: Phallusia mammillata (Phlebobranch ascidian)Description:This dataset contains live imaging data of embryonic development in Phallusia mammillata. The oocyte was microinjected with mRNAs encoding PH-GFP (membrane marker), H2B-mCherry (nuclear marker), and ERK-KTR-mClover (biosensor of ERK activity) prior to fertilization.Imaging conditions:The embryo was imaged live with a Luxendo MuVi-SPIM light-sheet microscope for ~5 hours, from the 32-cell stage (Tp1, St. 6) up to the late neurula stage (Tp150, St. 16). Acquisitions were performed every 2 minutes at 18 °C in artificial seawater (ASW, salinity: 38 ppt).Temporal alignment:Embryonic development in Phallusia mammillata shows natural variability in timing between individuals. To enable direct comparison across datasets, developmental time was normalized based on cell number. Phmamm-8 was chosen as the reference embryo, and Phmamm-16 was temporally aligned to it. In the normalized timeline, the acquisition of Phmamm-16 corresponds to a starting point (t0) of approximately 201 minutes post fertilization (tpf), with an effective acquisition interval of 1.90 minutes. This temporal alignment was performed using the ASCIDIAN package (see documentation for details). This allows stage-by-stage comparison of Phmamm-16 with Phmamm-8 and the other ascidian embryo datasets.Data processing:Fusion of images from four angles, whole-cell segmentation and temporal registration to correct for embryo movement were performed using the ASTEC pipeline (detailed documentation available here).Cell identification and fate assignments were executed using the ASCIDIAN package (documentation available here).Dataset versions:Biasuz et al., 2025 (v2):Fused and temporally registered images (.nii format): Available as "Phmamm-16-v2_intrareg_fuse.tar.gz".Intraregistered segmented images compensating embryo movements (.nii format): Available as "Phmamm-16-v2_intrareg_post.tar.gz".Individual cell geometric and naming properties (.xml format): Available as "Phmamm-16-v2-properties.tar.gz".For additional details about the .nii format, please refer to this resource.Important noteDue to a processing issue discovered after the deletion of the original RAWDATA, the fusion image for time step 83 was incorrectly generated. This erroneous image is preserved and marked with the suffix "_original". For analytical purposes, the fusion image for time step 83 provided in this dataset is duplicated from the preceding time step (time step 82).