Sleeping upside- down: Knockdown of a sleep- associated gene induces daytime sleep in the jellyfish Cassiopea

• 成果类型: Article
• 署名作者: Abrams, Michael J.; Ohdera, Aki; Francis, Diana A.; Donayre, Owen; Chen, Henry; Lu, Kevin; Hsu, Celeste Y.; Zeigler, Hannah; Harland, Richard M.
• 署名单位: University of California System; University of California Berkeley; University of Arizona
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11696
• DOI: 10.1073/pnas.2505074122
• 发表日期: 2025-07-22
• 关键词: expression; neurons; acetylcholinesterase; plasticity; nucleus; need

摘要

The conservation of sleep among diverse animals provides clear evidence for its physiological importance, but the extent of its regulatory conservation is unknown. The upside-down jellyfish Cassiopea xamachana sleeps, and this behavior is controlled by radially spaced marginal ganglia. After defining a sleep-wake threshold, we compared gene expression profiles of ganglia from animals deprived of sleep and found differential expression in many sleep-related genes including GABAergic, melatonergic, and cholinergic receptors. In particular, a nicotinic acetylcholine receptor alpha subunit-like (Chrnal-E) was strongly differentially expressed in sleep deprived animals. Animals deprived of sleep under both mechanical and light perturbations suggested chrnal-E as a key gene regulating sleep. We found that chemical cholinergic neuromodulators regulate pacemaker activity. Visualization of chrnal-E mRNA revealed it is expressed primarily within the ganglia, and that the area of expression expands after sleep deprivation. In order to confirm the functional role of chrnal-E, we developed RNAi for use in Cassiopea and determined that Chrnal-E promotes wakefulness. Finally, we field-sampled control and sleep deprived animals and found chrnal-E has lowest expression late at night in controls, while in sleep deprived animals, chrnal-E peaks at this time, supporting a link to wakefulness. Our finding that Cassiopea sleep is regulated by the cholinergic-like system underscores that some components of sleep regulation are deeply conserved even in an animal with a distributed nervous system.