Navigation Links
Traits produced by melanin may signal the bearer's capacity to combat free radicals

Some animal species have developed conspicuous traits produced by melanin pigments (for instance, dark manes in lions, black stripes in some birds and fishes). These traits are used as signals during contests for resources and/or contribute to increase the mating opportunities. However, the efficiency of these traits as signals depends on the fact that they transmit honest information about the quality of the bearer. This would be only assured by the fact that producing or maintaining the signal inevitability implies a cost. Thus, only those individuals able to afford the cost would also be able to conveniently express the signal.

Signals produced by melanin pigments have challenged our understanding because they are apparently cost-free and strongly controlled by the genotype. Melanin pigments are not as limited in production as carotenoids, yellow-red pigments common in vertebrates and only obtained from certain food items. In fact, melanin is constructed from amino acids present in proteins of the organism. However, recent experimental studies have become to disentangle the cost at the basis of melanin-based signals.

A recent article by Ismael Galvn at the Museo Nacional de Ciencias Naturales (CSIC) in Madrid and Carlos Alonso-Alvarez at IREC-CSIC, Spain, published in the online, open-access journal PLoS ONE proposes a novel hypothesis suggesting that these traits could indicate the ability of the bearer in fighting free radicals and oxidative damage. On the basis of medical bibliography, the researchers realized that tissue melanization is constrained in the presence of high enough levels of a key intracellular antioxidant named glutathione, which is considered one of the most powerful antioxidants present in virtually all animal cells.

The scientists hypothesized that low levels of this substance are also required to express melanin-based signals present in many animals. This implies that individuals able to express these signals should be also able to fight off an oxidative challenge, as a consequence of the low levels of the cited antioxidant. Only those animals with alternative antioxidant resources would be able to afford the cost of signaling. By chemically inhibiting the production of glutathione at the red blood cells, authors were able to significantly increase the size of a black stripe present in the feathers of the breast of great tits (a common garden bird). This stripe is a conspicuous trait playing a significant role during combats for territory, food or mates.

Furthermore, the reduction of glutathione levels also induced a mobilization of other antioxidant molecules to the blood plasma, supporting the cost, such as hypothesized by Alonso-Alvarez and colleagues.


Contact: Rebecca Walton
Public Library of Science

Related biology news :

1. DHS Expands Biometrics-at-Sea Program to the Florida Straits
2. At Boston symposium, NARSAD researchers report on genes and family traits
3. DNA study unlocks mystery to diverse traits in dogs
4. Biocapture surfaces produced for study of brain chemistry
5. Scientists identify the genes that cause blindness produced by corneal edema
6. Scientists find clue to mechanisms of gene signaling and regulation
7. Study finds blocking angiogenesis signaling from inside cell may lead to serious health problems
8. Researchers find signal that switches on eye development -- could lead to eye in a dish
9. Cell response to stress signals predicts tumors in women with common pre-breast cancer
10. Rong Li Lab reports protein interactions of MAP kinase signaling pathway
11. DNA variations signal lupus risk
Post Your Comments:
(Date:11/20/2015)... November 20, 2015 NXTD ) ... on the growing mobile commerce market and creator of ... Pereira , was recently interviewed on The RedChip ... on this weekend on Bloomberg Europe , Bloomberg ... --> NXTD ) ("NXT-ID" or the "Company"), ...
(Date:11/19/2015)... , Nov. 19, 2015  Based on its in-depth ... Sullivan recognizes BIO-key with the 2015 Global Frost & ... Frost & Sullivan presents this award to the company ... to the needs of the market it serves. The ... meets and expands on customer base demands, the overall ...
(Date:11/19/2015)... -- Although some 350 companies are actively involved in molecular ... according to Kalorama Information. These include Roche Diagnostics, Hologic, Abbott ... of the 6.1 billion-dollar molecular testing market, according to ... Diagnostic s .    ... one company and only a handful of companies can ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... November 26, 2015 ... Market 2016 - 2020 report analyzes that automating ... and quality in long-term samples, minimizing manual errors, ... Automation minimizes manual errors such as mislabeling or ... Further, it plays a vital role in blood ...
(Date:11/25/2015)...  PharmAthene, Inc. (NYSE MKT: PIP) announced  today that ... plan (Rights Plan) in an effort to preserve the ... Section 382 of the Internal Revenue Code (Code). ... of its NOLs could be substantially limited if the ... 382 of the Code. In general, an ownership change ...
(Date:11/25/2015)... 25, 2015 2 nouvelles études permettent ... les différences entre les souches bactériennes retrouvées dans la ... des êtres humains . Ces recherches  ouvrent une nouvelle ... prise en charge efficace de l,un des problèmes ... chats .    --> 2 nouvelles études ...
(Date:11/25/2015)... 2015 Studies reveal the differences ... and pave the way for more effective treatment for one ...   --> --> ... problems in cats, yet relatively little was understood about the ... have been conducted by researchers from the WALTHAM Centre for ...
Breaking Biology Technology: