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The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions
Published on: February 16, 2017
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Sea urchin larvae utilize light for regulating the pyloric opening
Junko Yaguchi1, Shunsuke Yaguchi2,3
1Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan.
BMC Biology
|April 6, 2021
Summary
Sea urchin larvae use light to control digestive activity via a pathway involving Go-Opsin and serotonin. This discovery sheds light on the evolution of light-dependent systems in animals.
Area of Science:
- Developmental biology
- Evolutionary biology
- Neurobiology
Background:
- Light is crucial for animal behavior and physiology, with visual and non-visual systems studied extensively.
- The evolution of light-dependent signaling in deuterostomes, particularly in Ambulacraria, is poorly understood.
- Knowledge of light-response pathways in Ambulacraria is lacking, hindering evolutionary insights.
Purpose of the Study:
- To investigate the role of light in non-visual systems of sea urchin larvae.
- To elucidate the molecular and cellular mechanisms of light-dependent digestive tract activity.
- To explore the evolutionary origins of light-regulated gut functions in deuterostomes.
Main Methods:
- Photoirradiation experiments on sea urchin larvae.
- Micro-surgical manipulations and gene knockdown studies.
- Immunohistochemistry to identify cell types and signaling molecules.
Main Results:
- Light exposure triggers pyloric opening in sea urchin larvae independently of food stimuli.
- Go-Opsin (sea urchin Opsin3.2)-expressing cells in the anterior neuroectoderm mediate light perception.
- A pathway involving Go-Opsin, serotonin, and nitric oxide (NO) regulates light-induced pyloric opening.
Conclusions:
- A novel light-Go-Opsin-serotonin-NO pathway controls pyloric opening in sea urchin larvae.
- This pathway may be conserved in Ambulacraria, suggesting an ancient role for light in regulating digestive functions.
- The findings provide insights into the primitive function of neuroectodermal neurons in regulating digestive tracts and the evolution of brain-gut interactions.
