Publication details
Oxidační stres jako mediátor kondiční závislosti karotenoidních ornamentů v pohlavním výběru u ptáků
| Title in English | Oxidative stress as a mediator of condition dependence of sexually selected ornaments in birds |
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| Year of publication | 2014 |
| Type | Conference abstract |
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| Citation | |
| Description | It is widely accepted that carotenoid-based ornaments act as honest signals of an individual quality during mate choice. However, despite two decades of intense research the proximate mechanism ensuring honesty of such signals remains unknown. Recently, there were proposed three hypotheses based on maintaining of redox homeostasis and suggesting that oxidative stress (OS) could be an universal mediator linking ornament expression with immune response and other metabolically demanding processes. Carotenoids can act as: (1) important antioxidants (AO) – trade-off between their allocation into AO defences and into ornamentation, (2) no influence of carotenoids on redox state – oxidation of carotenoids during elevated OS alters or destroys their colour or (3) prooxidants – products of carotenoid oxidation can be harmful at high concentrations. We tested these hypotheses in zebra finches (Taeniopygia guttatta). The effect of experimental manipulations of the level of OS and availability of carotenoids on bill colouration and antioxidant system in different tissue (plasma, liver, hearth) was evaluated in full-factorial design. For the first time, our results showed negative effect of OS on the carotenoid-based ornament in adult bird.This supports the plausibility of the hypothesis proposing OS as a mediator of condition-dependent expression of carotenoid-based ornaments. There was however no correlation between beak colour and measured AO mechanisms, which suggests that carotenoid ornaments do not act as direct signals of AO functions. We observed no AO effect of carotenoids. Moreover, when combined with elevated OS, high carotenoid levels intensified alterations of some of the AO mechanisms in plasma suggesting even harmful (prooxidant) effect of their degradation products. This study was supported by grants GAČR P506/12/2472, GAUK 283811 and by the project PROVAZ CZ.1.07/2.4.00/17.0138. |