Ontogeny of the rhythmic melatonin production in a precocial and an altricial bird, the Japanese quail and the European starling

Zeman, Michal; Gwinner, Eberhard

doi:10.1007/bf00216615

Cited by 24 publications

(20 citation statements)

References 23 publications

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“…Secondly, we provided evidence that the eggs of cavity-nesting species, which receive very little light (Cassey 2009;Holveck et al 2010), permitted more light, on average, to pass than eggs of open nesters. This may be necessary to assist with development (Shafey & Al-mohsen 2002;Shafey 2004) and to establish the embryonic circadian rhythm (Zeman & Gwinner 1993), in these extremely light poor environments. For example, in secondarily cavity-nesting House Sparrows Passer domesticus, greater light exposure speeds up embryonic development (Cooper et al 2011).…”

Section: Discussionmentioning

confidence: 99%

First light for avian embryos: eggshell thickness and pigmentation mediate variation in development and UV exposure in wild bird eggs

et al. 2014

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Summary 1.The avian embryo's development is influenced by both the amount and the wavelength of the light that passes through the eggshell. Commercial poultry breeders use light of specific wavelengths to accelerate embryonic growth, yet the effects of the variably patterned eggshells of wild bird species on light transmission and embryonic development remain largely unexplored. 2. Here, we provide the first comparative phylogenetic analysis of light transmission, through a diverse range of bird eggshells (74 British breeding species), in relation to the eggshell's thickness, permeability, pigment concentration and surface reflectance spectrum (colour). 3. The percentage of light transmitted through the eggshell was measured in the spectral range 250-700 nm. Our quantitative analyses confirm anecdotal reports that eggshells filter the light of the externally coloured shell. Specifically, we detected a positive relationship between surface eggshell reflectance ('brightness') and the percentage of light transmitted through the eggshell, and this relationship was strongest at wavelengths in the human-visible blue-green region of the spectra (c. 435 nm). 4. We show that less light passes through thicker eggshells with greater total pigment concentrations. By contrast, permeability (measured as water vapour conductance) did not covary significantly with light transmission. Eggs of closed-nesting species let more light pass through, compared with open nesters. 5. We postulate that greater light transmission is required to assist embryonic development under low light exposure. Importantly, this result provides an ecological explanation for the repeated evolution of immaculate, white-or pale-coloured eggshells in species nesting in enclosed spaces. 6. Finally, we detected correlative support for the solar radiation hypothesis, in that eggshells of bird species with a longer incubation period let significantly less of the potentially harmful, ultraviolet (UV) light pass through the eggshell. In summary, we demonstrate suites of avian eggshell properties, including eggshell structure and pigmentation, which are consistent with an evolutionary pressure to both enhance and protect embryonic development.

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Section: Discussionmentioning

confidence: 99%

First light for avian embryos: eggshell thickness and pigmentation mediate variation in development and UV exposure in wild bird eggs

et al. 2014

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“…The importance of light exposure for the synchronization of embryonic development with the photoperiod implies a crucial role of eggshell pigmentation in the establishment of a circadian clock of pre‐ and peri‐natal chicks of both precocial and altricial species (Zeman and Gwinner 1993, Zeman et al 1999). Specifically, shell pigmentation must not completely occlude light from the egg as the circadian rhythm established in the embryo determines the timing of hatching and the hatchlings day–night rhythm until at least three days after hatching (Zeman and Gwinner 1993, Zeman et al 1999).…”

Section: Circadian Rhythm Hypothesismentioning

confidence: 99%

Review: an embryo's eye view of avian eggshell pigmentation

Maurer¹,

Portugal²,

Cassey³

2011

Journal of Avian Biology

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Current research into the evolution and adaptive function of avian eggshell pigmentation, including maculation, has focused mostly on signalling‐based and structural function hypotheses but ignored the potential consequences of shell pigmentation for the developing avian embryo, especially in moderating the embryo's interaction with its light environment. The exposure of the eggs to sunlight that frequently accompanies avian incubation behaviour is one of the major evolutionary steps setting apart birds and reptiles, and coincides with the appearance of eggshell pigmentation. This suggests that shell pigments could play a major role in ensuring the successful development of the avian embryo. We propose that the effects of shell pigments on the egg contents should be considered in addition to established hypotheses of shell pigmentation such as crypsis, egg recognition or a possible structural function. This approach has the potential to identify trade‐offs between different pigment functions and to resolve some of the long standing paradoxa in the evolution of eggshell colour, such as the occurrence of conspicuous blue eggs in passerines or the secondary evolution of white eggshells in cavity nesters. In particular, we identify seven hypotheses, which address how the interaction of eggshell pigments and the light environment may influence embryonic development. These hypotheses are the: thermo‐regulation; UV‐B protection; photo‐acceleration; lateralization; circadian rhythm; photo‐reactivation; and antimicrobial defence. We believe that the understanding of eggshell pigmentation will greatly benefit from taking these hypotheses into consideration when studying the functional significance of eggshell pigmentation and suggest a number of promising directions for future experimental and comparative research.

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“…Although several studies have examined the ability of the pineal gland (including in the chicken) to rhythmically synthesize melatonin during development (e.g. [30–35]), none have addressed the issue of amplitude or rhythmicity of pineal NA in chickens at different developmental stages. Thus, in the present study we analysed changes in steady‐state levels of pineal NA in the chicken during two months posthatching.…”

Section: Introductionmentioning

confidence: 99%

Posthatching developmental changes in noradrenaline content in the chicken pineal gland

Zawilska¹,

Berezińska²,

Stasikowska³

et al. 2004

Journal of Pineal Research

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Noradrenaline (NA) levels in pineal gland of chickens at various posthatching stages (P2, P4, P8, P15, P30 and P57) were determined by high-performance liquid chromatography with electrochemical detection. Pineal NA content markedly increased between P2 and P30. P30 and P57 chickens, kept from the day of hatching under a 12:12 hr light-dark (LD) illumination cycle, exhibited rhythmic changes in pineal NA, with levels in the dark period being markedly higher than in the light period. In younger birds pineal NA concentrations did not show pronounced daily variations. In 4-wk-old chickens (P28-30) kept under constant darkness (DD), the rhythmic pattern of pineal NA persisted for 1 day (with higher values during the subjective dark phase than during the subjective light phase), but this disappeared 24 hr after the introduction of DD. In contrast, NA content in pineal glands isolated from birds maintained for 2 days under continuous light was similar to that found during the light phase of the LD cycle, and did not exhibit significant rhythmicity. In P30 chickens, pretreated with alpha-methyl-p-tyrosine (AMPT, an inhibitor of tyrosine hydroxylase, the key regulatory enzyme in the biosynthesis of catecholamines), pineal NA content declined slowly and monophasically during the light phase. During the dark phase the AMPT-induced decay of NA was biphasic--namely an initial rapid decline over the first 15 min which was followed by a slow-rate decline--an observation indicating that NA turnover was higher in the dark. Acute exposure of the dark-adapted P30 and P57 chickens to light significantly decreased pineal NA content, but did not affect pineal NA concentrations in younger birds. Our results suggest that the NA rhythm in the chicken pineal gland and its sensitivity to light regulation progressively develop during the first month of life.

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Ontogeny of the rhythmic melatonin production in a precocial and an altricial bird, the Japanese quail and the European starling

Cited by 24 publications

References 23 publications

First light for avian embryos: eggshell thickness and pigmentation mediate variation in development and UV exposure in wild bird eggs

First light for avian embryos: eggshell thickness and pigmentation mediate variation in development and UV exposure in wild bird eggs

Review: an embryo's eye view of avian eggshell pigmentation

Posthatching developmental changes in noradrenaline content in the chicken pineal gland

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