February 2, 2022
Keio University
A research team including students and faculty at the Keio University has taken the first step toward makingAscidiella aspersa(also known as the European sea squirt) a new model organism for bioimaging research by defining their developmental stages and constructing a three-dimensional embryological image resource. The team included Haruka M. Funakoshi and Takumi T. Shito, second-year master's students at Keio's Graduate School of Science and Technology along with Professor Kotaro Oka and Associate Professor Kohji Hotta of the Faculty of Science and Technology.
A. aspersais an ascidian belonging to the class of chordates—the closest relatives of vertebrates.A. aspersais a well-known invasive species that reproduces invasively not only in Japan but around the world, inflicting damage to shellfish aquaculture operations by attaching themselves to scallops. Despite this, embryos of this species are so transparent that they can transmit 90% of visible light, making scientists investigate their potential as a possible model organism for bioimaging research. However, until now there has been no standard developmental table for this species, an essential element in furthering such research.
As a first step to establishingA. aspersaas a model organism, researchers referenced the world standard developmental table of Ciona intestinalis, defining 28 different developmental stages forA. aspersathat span from fertilized egg to hatched larva. Additionally, they developed a web-based three-dimensional embryological image of the developmental table viewable by anyone in the world. This resource contains an astounding collection of over 3,000 cross-sectional and 3D images of the organism taken via confocal laser scanning microscopy.
TheA. aspersa3D image resource constructed in this study is indispensable for connecting different omics data to each developmental stage's spatiotemporal hierarchy, and is expected to aid in forming a system-level understanding of the embryonic development and phylogenic evolution of chordates—a classification that includes humans. If research on this species continues to expand the research foundation forA. aspersa, scientists believe that it could connect to potential measures to prevent these ascidians from attaching to and harming scallops.
The results of this study were published in the online edition of the Swiss scientific journalFrontiers in Cell and Developmental Biologyon December 17, 2021.
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