ArticleProceedings. Biological sciences2016
Multiple rod-cone and cone-rod photoreceptor transmutations in snakes: evidence from visual opsin gene expression.
Article in Proceedings. Biological sciences, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.
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.
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.
Who cites it
14 citing papers in PubMed, 60 citations in OpenAlex.
- Canonical PKCα-immunoreactive rod bipolar cells are present in nocturnal snakes but not in diurnal snakes.Scientific reports · 2026Article
- Deep-sea fish reveal an alternative developmental trajectory for vertebrate vision.Science advances · 2026Article
- Camouflage, conspicuousness, and inducible color change in a polymorphic, sexually dichromatic frog.Integrative organismal biology (Oxford, England) · 2025Article
- The evolutionary history and spectral tuning of vertebrate visual opsins.Developmental biology · 2023Review
- Developmental changes of opsin gene expression in ray-finned fishes (Actinopterygii).Proceedings. Biological sciences · 2022Article
- Chromosome-Level Genome Assembly Reveals Dynamic Sex Chromosomes in Neotropical Leaf-Litter Geckos (Sphaerodactylidae: Sphaerodactylus).The Journal of heredity · 2022Article
- Visual Gene Expression Reveals a cone-to-rod Developmental Progression in Deep-Sea Fishes.Molecular biology and evolution · 2021Article
- Eye-Transcriptome and Genome-Wide Sequencing for Scolecophidia: Implications for Inferring the Visual System of the Ancestral Snake.Genome biology and evolution · 2021Article
- Evolutionary adaptation of visual pigments in geckos for their photic environment.Science advances · 2021Article
- Visual adaptation of opsin genes to the aquatic environment in sea snakes.BMC evolutionary biology · 2020Article
- A dune with a view: the eyes of a neotropical fossorial lizard.Frontiers in zoology · 2019Article
- Molecular Adaptations for Sensing and Securing Prey and Insight into Amniote Genome Diversity from the Garter Snake Genome.Genome biology and evolution · 2018Article
- Daily activity patterns influence retinal morphology, signatures of selection, and spectral tuning of opsin genes in colubrid snakes.BMC evolutionary biology · 2017Article
- Pushing the limits of photoreception in twilight conditions: The rod-like cone retina of the deep-sea pearlsides.Science advances · 2017Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors at 7 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
In 1934, Gordon Walls forwarded his radical theory of retinal photoreceptor 'transmutation'. This proposed that rods and cones used for scotopic and photopic vision, respectively, were not fixed but could evolve into each other via a series of morphologically distinguishable intermediates. Walls' prime evidence came from series of diurnal and nocturnal geckos and snakes that appeared to have pure-cone or pure-rod retinas (in forms that Walls believed evolved from ancestors with the reverse complement) or which possessed intermediate photoreceptor cells. Walls was limited in testing his theory because the precise identity of visual pigments present in photoreceptors was then unknown. Subsequent molecular research has hitherto neglected this topic but presents new opportunities. We identify three visual opsin genes, rh1, sws1 and lws, in retinal mRNA of an ecologically and taxonomically diverse sample of snakes central to Walls' theory. We conclude that photoreceptors with superficially rod- or cone-like morphology are not limited to containing scotopic or photopic opsins, respectively. Walls' theory is essentially correct, and more research is needed to identify the patterns, processes and functional implications of transmutation. Future research will help to clarify the fundamental properties and physiology of photoreceptors adapted to function in different light levels.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.