ArticleHeredity2016
Relaxed selective constraints drove functional modifications in peripheral photoreception of the cavefish P. andruzzii and provide insight into the time of cave colonization.
Article in Heredity, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers.
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22 citing papers in PubMed, 44 citations in OpenAlex.
- Genomic and transcriptomic analyses reveal the adaptation to semi-aquatic and aquatic life in spiders.Molecular biology and evolution · 2026Article
- Conservation of dark CPD photolyase function in blind cavefish.Nature communications · 2025Article
- Population Genomics of Premature Termination Codons in Cavefish With Substantial Trait Loss.Molecular biology and evolution · 2025Article
- Sporadic feeding regulates robust food entrainable circadian clocks in blind cavefish.iScience · 2024Article
- Gene loss and relaxed selection ofProceedings. Biological sciences · 2024Article
- Eyeless cave-dwellingScience advances · 2023Article
- Mitochondrial phylogeography and molecular evolution of the rhodopsin visual pigment in troglobitic populations ofZoological research · 2023Article
- De novo human brain enhancers created by single-nucleotide mutations.Science advances · 2023Article
- Cavefishes in Chronobiological Research: A Narrative Review.Clocks & sleep · 2023Review
- Novel genome sequence of Chinese cavefish (Triplophysa rosa) reveals pervasive relaxation of natural selection in cavefish genomes.Molecular ecology · 2022Article
- Biogeography and eye size evolution of the ogre-faced spiders.Scientific reports · 2022Article
- Article
- Regulation of ddb2 expression in blind cavefish and zebrafish reveals plasticity in the control of sunlight-induced DNA damage repair.PLoS genetics · 2021Article
- Contrasting Gene Decay in Subterranean Vertebrates: Insights from Cavefishes and Fossorial Mammals.Molecular biology and evolution · 2021Article
- Prospects for sociogenomics in avian cooperative breeding and parental care.Current zoology · 2020Article
- Parallel selection on ecologically relevant gene functions in the transcriptomes of highly diversifying salmonids.BMC genomics · 2019Article
- Beyond drugs: the evolution of genes involved in human response to medications.Proceedings. Biological sciences · 2019Article
- Expression of extraocularPeerJ · 2019Article
- Extra-Visual Systems in the Spatial Reorientation of Cavefish.Scientific reports · 2018Article
- Mutations in blind cavefish target the light-regulated circadian clock gene, period 2.Scientific reports · 2018Article
Corrections and comments
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Authors and funding
9 authors at 4 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The genetic basis of phenotypic changes in extreme environments is a key but rather unexplored topic in animal evolution. Here we provide an exemplar case of evolution by relaxed selection in the Somalian cavefish Phreatichthys andruzzii that has evolved in the complete absence of light for at least 2.8 million years. This has resulted in extreme degenerative phenotypes, including complete eye loss and partial degeneration of the circadian clock. We have investigated the molecular evolution of the nonvisual photoreceptor melanopsin opn4m2, whose mutation contributes to the inability of peripheral clocks to respond to light. Our intra- and inter-species analyses suggest that the 'blind' clock in P. andruzzii evolved because of the loss of selective constraints on a trait that was no longer adaptive. Based on this change in selective regime, we estimate that the functional constraint on cavefish opn4m2 was relaxed at ∼5.3 Myr. This implies a long subterranean history, about half in complete isolation from the surface. The visual photoreceptor rhodopsin, expressed in the brain and implicated in photophobic behavior, shows similar evolutionary patterns, suggesting that extreme isolation in darkness led to a general weakening of evolutionary constraints on light-responsive mechanisms. Conversely, the same genes are still conserved in Garra barreimiae, a cavefish from Oman, that independently and more recently colonized subterranean waters and evolved troglomorphic traits. Our results contribute substantially to the open debate on the genetic bases of regressive evolution.
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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 OpenQuestion graph.