Related Papers
Herpetological Journal
Light-induced changes in pigmentation through ontogeny in cane toad tadpoles (Rhinella marina)
Lynne Beaty
Scientific reports
The first see-through frog created by breeding: description, inheritance patterns, and dermal chromatophore structure
2016 •
Mohammed Mafizul Islam
We have succeeded in creating see-through frogs from natural color mutants of the Japanese brown frog Rana japonica, which usually possesses an ochre or brown back; this coloration enables the organs, blood vessels, and eggs to be observed through the skin without performing dissection. We crossed two kinds of recessive color mutant (black-eyed and gray-eyed) frogs through artificial insemination, and F2 offspring produced frogs whose skin is translucent throughout the life cycle. Three kinds of dermal chromatophores-xanthophores, iridophores, and melanophores-are observed in a layered arrangement in the skin of wild-type frogs, but few chromatophores were present in the skin of the see-through frogs. The translucent skin enables observation of organ growth and cancer formation and progression in the animal, which can be monitored over its entire life without the need for dissection. See-through frogs thus provide a useful animal model for environmental, medical, and biological rese...
PeerJ
A histological analysis of coloration in the Peruvian mimic poison frog (Ranitomeya imitator)
Kyle Summers
Aposematism continues to be a phenomenon of central interest in evolutionary biology. The life history of the mimic poison frog, Ranitomeya imitator, relies heavily on aposematism. In order for aposematic signals to be effective, predators must be able to learn to avoid the associated phenotype. However, in R. imitator, aposematism is associated with four different color phenotypes that mimic a complex of congeneric species occurring across the mimic frog’s geographic range. Investigations of the underlying mechanics of color production in these frogs can provide insights into how and why these different morphs evolved. We used histological samples to examine divergence in the color production mechanisms used by R. imitator to produce effective aposematic signals across its geographic range. We measured the coverage of melanophores and xanthophores (the area covered by chromatophores divided by total area of the skin section) in each color morph. We find that morphs that produce ora...
Annals of the New York Academy of Sciences
Relationship between Melanotrope Cell Heterogeneity and Background Adaptation in the Frog Intermediate Lobea
1998 •
Hubert Vaudry
BMC Genomics
Being red, blue and green: the genetic basis of coloration differences in the strawberry poison frog (Oophaga pumilio)
2020 •
ARIEL IGNACIO RODRÍGUEZ
BackgroundAnimal coloration is usually an adaptive attribute, under strong local selection pressures and often diversified among species or populations. The strawberry poison frog (Oophaga pumilio) shows an impressive array of color morphs across its distribution in Central America. Here we quantify gene expression and genetic variation to identify candidate genes involved in generating divergence in coloration between populations of red, green and blue O. pumilio from the Bocas del Toro archipelago in Panama.ResultsWe generated a high quality non-redundant reference transcriptome by mapping the products of genome-guided and de novo transcriptome assemblies onto a re-scaffolded draft genome of O. pumilio. We then measured gene expression in individuals of the three color phenotypes and identified color-associated candidate genes by comparing differential expression results against a list of a priori gene sets for five different functional categories of coloration – pteridine synthesis, carotenoid synthesis, melanin synthesis, iridophore pathways (structural coloration), and chromatophore development. We found 68 candidate coloration loci with significant expression differences among the color phenotypes. Notable upregulated examples include pteridine synthesis genes spr, xdh and pts (in red and green frogs); carotenoid metabolism genes bco2 (in blue frogs), scarb1 (in red frogs), and guanine metabolism gene psat1 (in blue frogs). We detected significantly higher expression of the pteridine synthesis gene set in red and green frogs versus blue frogs. In addition to gene expression differences, we identified 370 outlier SNPs on 162 annotated genes showing signatures of diversifying selection, including eight pigmentation-associated genes.ConclusionsGene expression in the skin of the three populations of frogs with differing coloration is highly divergent. The strong signal of differential expression in pteridine genes is consistent with a major role of these genes in generating the coloration differences among the three morphs. However, the finding of differentially expressed genes across pathways and functional categories suggests that multiple mechanisms are responsible for the coloration differences, likely involving both pigmentary and structural coloration. In addition to regulatory differences, we found potential evidence of differential selection acting at the protein sequence level in several color-associated loci, which could contribute to the color polymorphism.
Journal of Microscopy and Ultrastructure
Comparative light and electron microscopic studies of dorsal skin melanophores of Indian toad, Bufo melanostictus
2014 •
Dr. Ishrat Naaz
Pigment composition of the bright skin in the poison toad Melanophryniscus rubriventris (Anura: Bufonidae) from Argentina
ines bonansea, Marcos Vaira
Zoomorphology
Pigment cell distribution in a rapid colour changing amphibian (Litoria wilcoxii)
2016 •
Jean-Marc Hero
2017 Rapid skin colour changes in amphibians and other colour changing animals are possible due to different distributions of pigment cells (chromatophores) and the movement of pigment within them. Amphibians possess three types of chromatophore: xanthophores, iridophores and melanophores which are collectively referred to as the dermal chromatophore unit. Male stony creek frogs (Litoria wilcoxii) are capable of undergoing rapid colour change from brown to yellow during amplexus. Based on previous studies, it is expected that this is achieved through a change in chromatophore distribution or pigment movement within chromatophores. We examined brown and yellow dorsal skin samples from male L. wilcoxii using light microscopy which allowed us to determine differences in chromatophore and pigment distribution between each colour phase. Additionally, we compared thigh skin sections, which are comprised of permanently yellow and black patches. We found that in dorsal skin sections of yellow frogs, melanophore pigment granules had aggregated to the centre of the melanophore underneath the yellow xanthophore, whilst pigment was dispersed throughout the melanophores, partially covering the xanthophores in brown frogs. Black thigh sections consisted of elongated melanophores, other cell types appeared to be absent. In contrast, yellow thigh sections contained only xanthophores. This study demonstrates that the process of colour change in L. wilcoxii is through pigment aggregation and dispersion within melanophores. In addition, we show that there is significant variation in pigment cell distribution between colour changing and non-colour changing integument.
Journal of Clinical Biochemistry and Nutrition
Skin Pigmentary Variants in Rana Nigromaculata
2006 •
Ichiro Tazawa
Vision Research
Unusual choroid pigment distribution in the retina of a south american frog
1980 •
Valdir Pessoa
