Developmental Table and Three-Dimensional Embryological Image Resource of the Ascidian .

is an ascidian in the class of chordates-the closest relatives of vertebrates. . is a potential model organism for bio-imaging studies due to its extremely transparent embryos as well as is a globally distributed cosmopolitan species. However, there is no standard developmental table for this organism. Here, as a first step to establish . as a model organism, we report a standard developmental table as a web-based digital image resource. This resource used confocal laser scanning microscopy to scan more than 3,000 cross-sectional images and 3D-reconstructed images of . embryos during embryogenesis. With reference to the standardized developmental table of type A, 26 different developmental stages (Stages 1-26) from fertilized eggs to hatched larvae were redefined for . . Cell lineages up to the cleavage period were annotated: The cleavage patterns, the embryonic morphology, and the developmental time were then compared with . We found that the cleavage patterns and developmental time up to the neurula period in . were extremely conserved versus. . The ratio of the trunk and tail length in the tailbud period were smaller than indicating a relatively short tail. In addition, the timing of the bending of the tail is earlier than . This . standard 3D digital resource is essential for connecting different omics data to different spatiotemporal hierarchies and is useful for a system-level understanding of chordate development and evolution.