Evidence map›Paper›PMID 40101169›Full record

ArticlePLoS genetics2025

Evolution of canonical circadian clock genes underlies unique sleep strategies of marine mammals for secondary aquatic adaptation.

Daiqing Yin, Zhaomin Zhong, Fan Zeng, Zhikang Xu, Jing Li, Wenhua Ren, Guang Yang, Han Wang, Shixia Xu

Abstract read
In one paragraph

Article in PLoS genetics, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Daiqing YinJiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.ORCID https://orcid.org/0009-0007-6682-5864
Zhaomin ZhongCenter for Circadian Clocks, Soochow University, Suzhou, Jiangsu, PR China.
Fan ZengJiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
Zhikang XuJiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
Jing LiJiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
Wenhua RenJiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
Guang YangJiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
Han WangCenter for Circadian Clocks, Soochow University, Suzhou, Jiangsu, PR China.
Shixia XuJiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.ORCID https://orcid.org/0009-0000-6496-3744

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

To satisfy the needs of sleeping underwater, marine mammals, including cetaceans, sirenians, and pinnipeds, have evolved an unusual form of sleep, known as unihemispheric slow-wave sleep (USWS), in which one brain hemisphere is asleep while the other is awake. All aquatic cetaceans have only evolved USWS without rapid eye movement (REM) sleep, whereas aquatic sirenians and amphibious pinnipeds display both bihemispheric slow-wave sleep (BSWS) and USWS, as well as REM sleep. However, the molecular genetic changes underlying USWS remain unknown. The present study investigated the evolution of eight canonical circadian genes and found that positive selection occurred mainly within cetacean lineages. Furthermore, convergent evolution was observed in lineages with USWS at three circadian clock genes. Remarkably, in vitro assays showed that cetacean-specific mutations increased the nuclear localization of zebrafish clocka, and enhanced the transcriptional activation activity of Clocka and Bmal1a. In vivo, transcriptome analysis showed that the overexpression of the cetacean-specific mutant clocka (clocka-mut) caused the upregulation of the wakefulness-promoting glutamatergic genes and the differential expression of multiple genes associated with sleep regulation. In contrast, the GABAergic and cholinergic pathways, which play important roles in promoting sleep, were downregulated in the bmal1a-mut-overexpressing zebrafish. Concordantly, sleep time of zebrafish overexpressing clocka-mut and bmal1a-mut were significantly less than the zebrafish overexpressing the wild-type genes, respectively. These findings support our hypothesis that canonical circadian clock genes may have evolved adaptively to enhance circadian regulation ability relating to sleep in cetaceans and, in turn, contribute to the formation of USWS.

Indexed as

Adaptation, PhysiologicalCetaceaCircadian ClocksEvolution, MolecularSleepSleep, Slow-WaveAnimalsAquatic OrganismsCircadian RhythmCLOCK ProteinsMammalsPhylogenyZebrafishCLOCK Proteins

Identifiers

PMID40101169
PMCPMC11919277

What Socratic holds

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.