Sex-specific effects of prenatal testosterone on nestling plasma antioxidant capacity in the zebra finch

Tobler, Michael; Sandell, Maria I.

doi:10.1242/jeb.020826

Cited by 56 publications

(41 citation statements)

References 47 publications

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“…higher in T-injected birds), although the difference was not significant. By contrast, Tobler and Sandell (Tobler and Sandell, 2009) found lower plasma antioxidant levels in male, but not in female, zebra finches (Taeniopygia guttata) hatched from T-injected yolks. These opposite results might be due to disparities in the methods used to assess antioxidants.…”

Section: Discussionmentioning

confidence: 70%

“…These opposite results might be due to disparities in the methods used to assess antioxidants. Alternatively, sex-related differences in the antioxidant metabolism of both species might arise owing to the different rearing conditions of nestlings, as, while our study was conducted with wild great tits, Tobler and Sandell (Tobler and Sandell, 2009) studied zebra finches in captivity, which could result in the availability of antioxidants being drastically different between the studied populations. Tobler and Sandell (Tobler and Sandell, 2009) suggested that yolk T could have programmed the nestling metabolism, leading to a higher T production in males, and ultimately, to a weaker TAS.…”

Section: Discussionmentioning

confidence: 99%

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Yolk testosterone shapes the expression of a melanin-based signal in great tits: an antioxidant-mediated mechanism?

Galván

Alonso‐Álvarez

2010

Journal of Experimental Biology

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SUMMARYConspicuous traits produced by melanin deposition in integuments are often involved in visual communication. The information content of melanin-based signals is unclear as their expression is tightly controlled by genes and, apparently, is less dependent on individual condition. In birds, high heritabilities have been attributed to melanin-based plumages, often on the basis of eggswapping manipulations (cross-fostering experiments). However, it is well known that female birds can differentially transfer testosterone to the egg yolk. Furthermore, high testosterone levels have been related to high oxidative stress. As we recently found that oxidative stress experienced during development influences the expression of melanin-based traits, here we manipulated the level of yolk testosterone in great tits (Parus major) to assess the influence of this maternal effect on the expression of the black breast stripe, a well-known melanin-based signal. We predicted that fledglings hatched from eggs with high testosterone levels will not only show larger black stripes but also experience changes in their antioxidant machinery. Indeed, the size of the black stripe of great tits hatched from testosterone-injected eggs was almost double that of controls. Furthermore, the same individuals showed a trend to higher levels of circulating antioxidants, which suggests an adaptive response against some testosterone-induced oxidative challenge.

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Section: Discussionmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 99%

Yolk testosterone shapes the expression of a melanin-based signal in great tits: an antioxidant-mediated mechanism?

Galván

Alonso‐Álvarez

2010

Journal of Experimental Biology

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“…Recent evidence suggests that higher concentrations of yolk testosterone might directly or indirectly (i.e. through an increased growth rate [30]) impair antioxidant defences and increase the production of reactive oxygen and nitrogen species [8,9]. For example, chicks that have hatched from testosterone-injected eggs suffered from reduced plasma antioxidant levels [8] (zebra finch, Taeniopygia guttata) and DNA damage repair efficiency in response to an oxidative challenge [9] (domestic chickens, Gallus gallus).…”

Section: Discussionmentioning

confidence: 99%

“…through an increased growth rate [30]) impair antioxidant defences and increase the production of reactive oxygen and nitrogen species [8,9]. For example, chicks that have hatched from testosterone-injected eggs suffered from reduced plasma antioxidant levels [8] (zebra finch, Taeniopygia guttata) and DNA damage repair efficiency in response to an oxidative challenge [9] (domestic chickens, Gallus gallus). Our result suggests that species with a fast growth stimulated by high levels of yolk testosterone might counterbalance the negative effects of this developmental strategy on oxidative stress levels by allocating high levels of antioxidants, and particularly vitamin E, to their eggs.…”

Section: Discussionmentioning

confidence: 99%

Co-adjustment of yolk antioxidants and androgens in birds

Giraudeau

Ducatez

2016

Biol. Lett.

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Mothers can shape the developmental trajectory of their offspring through the transmission of resources such as hormones, antioxidants or immunoglobulins. Over the last two decades, an abundant literature on maternal effects in birds has shown that several of these compounds (i.e. androgens, glucocorticoids and antioxidants) often influence the same offspring phenotypic traits (i.e. growth, immunity or oxidative stress levels), making interaction effects between egg components a likely scenario. However, the potential interactive effects of maternally transmitted compounds on offspring development and potential co-adjustment of these compounds within an egg are still poorly understood. Here, we report the results of an interspecific comparative analysis on birds' egg yolk composition (i.e. androgens and antioxidants) where we found that yolk carotenoid and vitamin E concentrations are positively associated, supporting the hypothesis that these two antioxidants act in synergy. The concentrations of vitamin E also increased with increasing concentrations of testosterone. This last result confirms the emerging idea that androgens and antioxidants are co-adjusted within eggs and that maternally transmitted antioxidants might limit the potential direct and indirect effects of prenatal exposure to high testosterone levels on oxidative stress.

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“…2005), increased energy expenditure (Tobler et al. 2007), reduced antioxidant activity (in males only: Tobler and Sandell 2009), nestling survival (Sockman and Schwabl 2000; Muriel et al. 2015), and even maybe long‐term survival (Ruuskanen et al.…”

Section: Introductionmentioning

confidence: 99%

Maternal effects as drivers of sibling competition in a parent–offspring conflict context? An experimental test

Merkling

Perrot

Helfenstein

et al. 2016

Ecology and Evolution

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Maternal effects occur when the mother's phenotype influences her offspring's phenotype. In birds, differential allocation in egg yolk components can allow mothers to compensate for the competitive disadvantage of junior chicks. We hypothesize that the parent–older chick conflict peaks at intermediate conditions: parents benefit from the younger chick(s) survival, but its death benefits the older chick in terms of growth and survival. We thus expect maternal compensation to follow a bell‐shaped pattern in relation to environmental conditions. We studied a black‐legged kittiwake (Rissa tridactyla) population where previous results revealed increased allocation of yolk testosterone in younger as compared to older chicks in intermediate conditions, in line with our theoretical framework. We therefore predicted a maternally induced increase in aggressiveness, growth, and survival for younger chicks born in intermediate environmental conditions. Controlling for parental effects and chick sex, we manipulated food availability before egg laying to create a situation with intermediate (Unfed group) and good (Fed group) environmental conditions. Within each feeding treatment, we further created experimental broods where the natural hatching order was reversed to maximize our chances to observe an effect of feeding treatment on the younger chicks' aggressiveness. As predicted, we found that chick aggressiveness was higher in younger chicks born from the Unfed group (i.e., in intermediate environmental conditions), but only when they were put in a senior position, in reversed broods. Predictions on growth and survival were not confirmed. Mothers thus seem to favor the competitiveness of their younger chick in intermediate conditions via egg yolk components, but our study also suggests that hatching asynchrony need to be small for maternal compensation to be efficient. We emphasize the need for further studies investigating other chick behaviors (e.g., begging) and focusing on the relative role of different yolk components in shaping parent–offspring conflict over sibling competition.

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Sex-specific effects of prenatal testosterone on nestling plasma antioxidant capacity in the zebra finch

Cited by 56 publications

References 47 publications

Yolk testosterone shapes the expression of a melanin-based signal in great tits: an antioxidant-mediated mechanism?

Yolk testosterone shapes the expression of a melanin-based signal in great tits: an antioxidant-mediated mechanism?

Co-adjustment of yolk antioxidants and androgens in birds

Maternal effects as drivers of sibling competition in a parent–offspring conflict context? An experimental test

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