RAMNe is a digital image resource integrating different species of ascidians. It contains 3D morphology data of three ascidians in early developmental stage consisting of 34,400 images. RAMNe was firstly constructed within two species, Ciona robusta and Ascidiella aspersa (Funakoshi et al., 2021). It was updated to v2 adding the images of Styela clava in 2023 (in submission).
Styela clava, known as leathery sea squirt, belongs to Ascidiacea, Chordata. It shows high environmental adaptation that globally distributed along the coast and the adults can be collected all year round. The genome of S. clava is approximately 340 Mb with 17480 genes. Recent studies on the transcription factors and chromosomal -level gene expression in Styela have revealed a significant increase in the number of transposons and heat shock protein-related genes, providing insights into the organism's mechanisms for environmental adaptation based on its genome and molecular networks (Wei et al. 2020). Moreover, the comprehensive genome of this species has been incorporated into EDomics, providing a comprehensive and comparative multiomics platform for the animal evo-devo community to decipher the entire history of the tree of life development and evolution (Wei et al. 2022).
In this study, we established a standard developmental table and provided the web-based digital image resource of S. clava early embryogenesis by confocal laser scanning microscopy. We observed and defined the embryogenesis and larval development in S. clava, identifying 22 stages from fertilization eggs to hatching larvae based on the morphology and developmental events (Hotta et al., 2007). These stages were categorized into six periods: zygote, cleavage, gastrula, neurula, tailbud, and larva. For each stage, there were corresponding differential interference contrast (DIC) images of embryos with chorion, DIC images without chorion, high resolution three-dimensional (3D) reconstruction images, and cross-sectional images by Phalloidin 488 staining.
RAMNe provides a comprehensive display of the spatiotemporal morphological changes that occur during the early developmental processes of S. clava. It enables easy access to 3D angles of each embryo and slice slices of different layers, and facilitates systematic comparisons of the morphology and development time of Ciona and Ascidiella at the same stage, which is valuable for studying chordate development.
Please refer to:
"Establishment of developmental atlas and transgenetic tools in ascidian Styela clava"
Marine Life Science & Technology,
Boyan Lin, Wenjie Shi, Qiogxuan Lu, Takumi T. Shito, Haiyan Yu, Bo dong (2023)
DOI: https://doi.org/10.1007/s42995-023-00200-2
Website construction: Takumi T. Shito, Haruka M. Funakoshi
Photo of S. clava: Boyan Lin, Wenjie Shi