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Pheomelanin synthesis varies with protein food abundance in developing goshawks

The accumulation of the amino acid cysteine in lysosomes produces toxic substances, which are avoided by a gene (CTNS) coding for a transporter that pumps cystine out of lysosomes. Melanosomes are lysosome-related organelles that synthesize melanins, the most widespread pigments in animals. The synthesis of the orange melanin, termed pheomelanin, depends on cysteine levels because the sulfhydryl group is used to form the pigment. Pheomelanin synthesis may, therefore, be affected by cysteine homeostasis, although this has never been explored in a natural system. As diet is an important source of cysteine, here such an effect was indirectly tested by searching for an association between food abundance and pheomelanin content of feathers in a wild population of Northern goshawk Accipiter gentilis. As predicted on the basis that CTNS expression may inhibit pheomelanin synthesis and increase with food abundance -as previously found in other strictly carnivorous birds- the feather pheomelanin content in nestling goshawks, but not in adults, decreased as the abundance of prey available to them increased. In contrast, variation in the feather content of the non-sulphurated melanin form (eumelanin) was only explained by sex in both nestlings and adults. The feather pheomelanin content of nestlings was also found negatively related to that of their mothers, suggesting a relevant environmental influence on pheomelanin synthesis. Overall, these findings suggest that variation in pheomelanin synthesis may be a side effect of the maintenance of cysteine homeostasis. This may help explaining variability in the expression of pigmented phenotypes. informacion[at]ebd.csic.es: Galván et al (2019) Pheomelanin synthesis varies with protein food abundance in developing goshawks. J Comp Physiol B https://doi.org/10.1007/s00360-019-01222-y


https://link.springer.com/article/10.1007/s00360-019-01222-y
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Content with tag melanogenesis .

Pheomelanin synthesis varies with protein food abundance in developing goshawks

The accumulation of the amino acid cysteine in lysosomes produces toxic substances, which are avoided by a gene (CTNS) coding for a transporter that pumps cystine out of lysosomes. Melanosomes are...

Recent shift in the pigmentation phenotype of a wild Neotropical primate

The colors of primates are among the most diverse phenotypes in mammals. These colors are mostly produced by the deposition of melanin pigments in hairs. Many species show considerable variability...

Raman spectroscopy quantification of eumelanin subunits in natural unaltered pigments

Eumelanins are large polymers composed of 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). ROS generation is higher during the synthesis of DHI than during the synthesis...

Color measurement of the animal integument predicts the content of specific melanin forms

The appearance of animals largely depends on melanins present in their integument. However, it is unclear how different melanin forms create different animal color phenotypes. Reflectance...

Review of the main characteristics of bird integumentary melanins

Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding...