Pheomelanin in the skin of <i>Hymenochirus boettgeri</i> (Amphibia: Anura: Pipidae)

Wolnicka-Głubisz, Agnieszka; Pecio, Anna; Podkowa, Dagmara; Kolodziejczyk, Lukasz M.; Płonka, Przemysław M.

doi:10.1111/j.1600-0625.2012.01511.x

Cited by 44 publications

(42 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Phaeomelanin was thought to be restricted to warm-blooded animals, presumably evolving convergently for metabolic reasons (40). However, it appears that phaeomelanin is actually more widespread in ectothermic organisms than previously thought (14)(15)(16)(17). As proposed recently (20), the more pure melanins in mammals and birds could reflect the marked shift in external integument with the evolution of hair and feathers for insulation in these warm-blooded animals rather than physiology (13).…”

Section: Melanosome Shrinkage During Burial Diagenesis and Maturationmentioning

confidence: 55%

“…In extant mammals and birds, eumelanosomes are oblong, with a higher aspect ratio than phaeomelanosomes, which are smaller and more spherical (3,13). It is not clear whether other amniotes or fishes produce morphologically distinct melanosomes, but chemical evidence distinguishes pure eumelanin and phaeomelanin in turtles (14), and phaeomelanin has been tentatively reported in frogs (15), fish (16), and chitons (Mollusca) (17). Melanosome morphology currently serves as the primary basis for interpretations of fossil feather color, as it correlates with several distinct melaninbased colors and iridescence in modern birds (1,3,4).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Chemical, experimental, and morphological evidence for diagenetically altered melanin in exceptionally preserved fossils

Colleary

Dolocan²,

Gardner

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

107

170

View full text Add to dashboard Cite

In living organisms, color patterns, behavior, and ecology are closely linked. Thus, detection of fossil pigments may permit inferences about important aspects of ancient animal ecology and evolution. Melanin-bearing melanosomes were suggested to preserve as organic residues in exceptionally preserved fossils, retaining distinct morphology that is associated with aspects of original color patterns. Nevertheless, these oblong and spherical structures have also been identified as fossilized bacteria. To date, chemical studies have not directly considered the effects of diagenesis on melanin preservation, and how this may influence its identification. Here we use time-of-flight secondary ion mass spectrometry to identify and chemically characterize melanin in a diverse sample of previously unstudied extant and fossil taxa, including fossils with notably different diagenetic histories and geologic ages. We document signatures consistent with melanin preservation in fossils ranging from feathers, to mammals, to amphibians. Using principal component analyses, we characterize putative mixtures of eumelanin and phaeomelanin in both fossil and extant samples. Surprisingly, both extant and fossil amphibians generally exhibit melanosomes with a mixed eumelanin/phaeomelanin composition rather than pure eumelanin, as assumed previously. We argue that experimental maturation of modern melanin samples replicates diagenetic chemical alteration of melanin observed in fossils. This refutes the hypothesis that such fossil microbodies could be bacteria, and demonstrates that melanin is widely responsible for the organic soft tissue outlines in vertebrates found at exceptional fossil localities, thus allowing for the reconstruction of certain aspects of original pigment patterns.

show abstract

Section: Melanosome Shrinkage During Burial Diagenesis and Maturationmentioning

confidence: 55%

mentioning

confidence: 99%

Chemical, experimental, and morphological evidence for diagenetically altered melanin in exceptionally preserved fossils

Colleary

Dolocan²,

Gardner

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

107

170

View full text Add to dashboard Cite

show abstract

“…1h). The presence of the pigment pheomelanin, contained within pheomelanosomes, has recently been demonstrated in amphibian skin (Wolnicka-Glubisz et al 2012); however this does not Fig. 6 XANES spectra of zinc standards, blonde human hair and FS003b tadpole at the zinc K edge shown as the normalized absorption (a) and the first derivative (b).…”

Section: Physical Structurementioning

confidence: 99%

Bacteria or melanosomes? A geochemical analysis of micro-bodies on a tadpole from the Oligocene Enspel Formation of Germany

Barden

Bergmann

Edwards

et al. 2014

Palaeobio Palaeoenv

View full text Add to dashboard Cite

Many exceptionally preserved fossils have long been thought the product of preservation by bacterial autolithification, based largely upon the presence of, micronsized, spherical or elongate bodies on their surface. This has recently been challenged by studies of similar fossils which cite morphological and geochemical evidence that these structures could be fossilized melanosomes, melanin-containing organelles. We geochemically analysed a tadpole from the Oligocene Enspel Formation, Germany, which displays such spherical bodies on its surface. Pyrolysis gas chromatography mass spectroscopy (Py-GCMS) and Fourier transform infrared spectrometry (FTIR) indicate that the organic remains of the tadpole are original and are not the result of external contamination, shown by the different chemical compositions of the fossil and its enclosing matrix. Py-GCMS also demonstrates the presence of bacterial and plant biomarkers in the matrix but not the tadpole, suggesting that the spherical bodies are unlikely to be bacterial, and also that such fossils do not develop their dark colour from incorporating plant material, as has been suggested. X-ray absorption spectroscopy (XAS) shows high levels of organically bound Zn(II) in the fossilized soft tissue, a metal known to chelate both eu-and pheomelanin.The zinc in the tadpole shows greater similarity to that bound in pheomelanized extant samples than to that in eumelanized ones. Though further geochemical analysis of both pure pheomelanin and bacterial samples is required to completely exclude a bacterial origin, these results are in line with a pheomelanic origin for the spherical bodies on the tadpole.

show abstract

“…Comparison of the lineshape of these EPR spectra indicates that eumelanin reveals the simple single line (Figure 2a) and EPR line of pheomelanin reveals the complex shape with the unresolved hyperine structure (Figure 2b). The lineshapes of the EPR spectra of DOPAmelanin [17-19, 26, 34-37] and pheomelanin [22,31,[38][39][40] were presented in a lot of papers. EPR spectra were measured for free radicals in melanotic tumor cells [44][45][46][47][48][49][50][51][52].…”

Section: Introductionmentioning

confidence: 99%

“…This absorption is the base of electron paramagnetic resonance (EPR) spectroscopy [41][42][43]. Free radicals in eumelanin [17-19, 26, 40] and pheomelanin [22,31,[38][39][40] are responsible for the EPR spectra, which difer in the shape. Typical EPR spectra of the model eumelanin DOPA-melanin and pheomelanin are shown in Figure 2.…”

Section: Introductionmentioning

confidence: 99%

Application of Electron Paramagnetic Resonance Spectroscopy to Examine Free Radicals in Melanin Polymers and the Human Melanoma Malignum Cells

Pilawa¹,

Zdybel²,

Chodurek³

2017

Melanin

View full text Add to dashboard Cite

The studies of free radicals in melanin and the human melanoma malignum cells by an X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy were presented. The original results were compared with those published earlier. The aim of this work was application of the advanced spectral analysis to determine free radical properties in melanin biopolymers obtained from diferent melanotic tumor cells and free radicals existing in the human melanoma cells. Magnetic spin-latice interactions in melanin samples were tested. The evolution of lineshape of tumor cells with increasing of microwave power was determined to conirm their complex free radical system. The useful shape parameters were proposed. The shape of melanotic tumor cells was analyzed. EPR spectra of free radicals in the melanin isolated from diferent tumor cells measured in the wide range of microwave power were analyzed. The melanins were obtained from the control tumor cells and the cells cultured with the several antitumor substances. The usefulness of the electron paramagnetic resonance spectroscopy was conirmed.

show abstract

Pheomelanin in the skin of Hymenochirus boettgeri (Amphibia: Anura: Pipidae)

Cited by 44 publications

References 33 publications

Chemical, experimental, and morphological evidence for diagenetically altered melanin in exceptionally preserved fossils

Chemical, experimental, and morphological evidence for diagenetically altered melanin in exceptionally preserved fossils

Bacteria or melanosomes? A geochemical analysis of micro-bodies on a tadpole from the Oligocene Enspel Formation of Germany

Application of Electron Paramagnetic Resonance Spectroscopy to Examine Free Radicals in Melanin Polymers and the Human Melanoma Malignum Cells

Contact Info

Product

Resources

About