Jennifer Mansfield, professor of biological sciences, was co-author on a study published in The Biological Bulletin on March 8, 2023, titled “In Amphioxus Embryos, Some Neural Tube Cells Resemble Differentiating Coronet Cells of Fishes and Tunicates.” The work analyzed embryonic neural cells of amphioxus, also called lancelets. Lancelets are small, fishlike marine animals that are among the closest living relatives of vertebrates. They are thus invaluable for understanding vertebrate evolutionary history.
The research team used transmission electron microscopy to examine the anterior (diencephalic) region of the neural tube in early amphioxus embryos. They report previously unknown cells that, based on the presence of a modified type of cilia on their surfaces, strongly resemble immature coronet cells of other chordates.
Coronet cells are thought to act in nonvisual photoreception (light detection), but their functions and evolutionary history are not well understood. Future work is needed to elucidate the function of coronet-like cells in amphioxus embryos and their relation to coronet cells of other groups. Their discovery raises new questions about the shared ancestry of this cell type or organelle in the phylum Chordata.
The current work arose in part from a collaborative TEM study of amphioxus by the research team, sponsored by a Presidential Research Award from Barnard College.