Browsing by Author "Karadas, Filiz"

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Antioxidant Systems in Chick Embryo Development. Part 1. Vitamin E, Carotenoids and Selenium
(Keai Publishing Ltd, 2016) Surai, Peter F.; Fisinin, Vladimir I.; Karadas, Filiz
Chick viability is known to be an important factor determining profitability of the poultry industry. Chick embryo tissues contain a high proportion of highly polyunsaturated fatty acids in the lipid fraction and therefore need antioxidant defence. The antioxidant system of the developing embryo and newly hatched chick includes the antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase), water-soluble antioxidants (ascorbic acid, taurine, carnitine, glutathione, etc.), fat-soluble antioxidants (vitamin E, carotenoids, coenzyme Q) as well as selenium (Se). In fact, the high levels of endogenous antioxidants within the egg and embryonic tissues can clearly serve as a major adaptive mechanism for the protection of the tissue during the oxidative stress experienced at hatching. It has been shown that among different nutrients in the maternal diet which could significantly affect chick embryo development and their viability in the early posthatch life, natural antioxidants have been suggested to play a central role. Our data indicate that increased supplementation of the maternal diet can substantially increase concentrations of vitamin E, carotenoids (especially canthaxanthin) and Se in developing chick tissues and significantly decrease susceptibility to lipid peroxidation being effective nutritional tools to deal with various commercial stresses in poultry production. (C) 2016, Chinese Association of Animal Science and Veterinary Medicine. Production and hosting by Elsevier B. V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Antioxidants and Embryo Phenotype: Is There Experimental Evidence for Strong Integration of the Antioxidant System
(Company of Biologists Ltd, 2017) Possenti, Cristina Daniela; Karadas, Filiz; Colombo, Graziano; Caprioli, Manuela; Rubolini, Diego; Milzani, Aldo; Parolini, Marco
Organisms have evolved complex defense systems against oxidative stress. Bird eggs contain maternally derived antioxidants that protect embryos from oxidative damage. The antioxidant system components are thought to be integrated, but few studies have analyzed the covariation between antioxidant concentrations, embryo `oxidative status' and morphology. In addition, no study has tested the effects of experimental change in yolk antioxidant concentration on other antioxidants, on their reciprocal relationships and on their relationships with embryo oxidative status or growth, which are expected if antioxidants defenses are integrated. In yellowlegged gull (Larus michahellis) embryos, we analyzed the covariation between several antioxidants, markers of `oxidative status' [total antioxidant capacity (TAC), concentration of pro-oxidants (TOS), lipid peroxidation (LPO) and protein carbonylation (PC)] in the yolk, liver and brain, and morphology. Yolk and liver antioxidant concentrations were positively correlated reciprocally and with embryo size, and positively predicted TAC but not oxidative status. TOS and LPO were positively correlated in the liver, while TAC and LPO were negatively correlated in the brain. Weak relationships existed between antioxidants and TOS, PC and LPO. The effects of antioxidants on oxidative status and morphology were non-synergistic. An experimental physiological increase in yolk vitamin E had very weak effects on the relationships between other antioxidants or oxidative status and vitamin E concentration, the concentration of other antioxidants or oxidative status; the covariation between other antioxidants and oxidative status, and relationships between morphology or oxidative status and other antioxidants, challenging the common wisdom of strong functional relationships among antioxidants, at least for embryos in the wild.
Changes in Broiler Chick Tissue Concentrations of Lipid-Soluble Antioxidants Immediately Post-Hatch
(Elsevier Science inc, 2011) Karadas, Filiz; Surai, Peter F.; Sparks, Nicholas H. C.
The antioxidant protection of the chicken (Gallus gallus) embryo during incubation and early postnatal development plays an important role in chick viability. To assess the antioxidant capacity of the newly hatched chick, we determined the concentrations of vitamin A, vitamin E, carotenoids and coenzyme Q(10) in the major tissues of chicks which had been held in an incubator for up to 36 h post-hatch. Concentrations of total carotenoids and free retinol and retinol esters in the tissues did not differ significantly over the 36 h period post-hatch (p > 0.05). In contrast concentrations of vitamin E (alpha-tocopherol, gamma-tocopherol, and alpha-tocotrienol and gamma-tocotrienol) in various tissues (liver, heart, brain and leg muscle) decreased significantly in chicks that had been held in the incubator for 36 h when compared to younger chicks that were held for up to 18 h. Comparatively high concentrations of coenzyme Q(10) were detected in the yolk sac membrane, liver and heart, the concentrations being dependent on age of chicks, the highest value being recorded 18 h post-hatch. In most of the tissues studied, coenzyme Q(10) concentrations decreased substantially between 18 and 36 h post-hatch. This study demonstrated that there are tissue-specific changes in the concentrations of the major antioxidants (vitamin E and coenzyme Q(10)) during the 36 h post-hatch. (c) 2011 Elsevier Inc. All rights reserved.
A Comparison of Fat-Soluble Antioxidants in Wild and Farm-Reared Chukar Partridges (Alectoris Chukar)
(Elsevier Science inc, 2017) Karadas, Filiz; Moller, Anders Pape; Karagecili, Mehmet Resit
This study assessed differences in antioxidant (carotenoid, retinol, retinol-ester, vitamin E and coenzyme Q(10)) composition of egg yolk and tissue in chukar partridges (Alectoris chukar) newly hatched from eggs of birds maintained in captivity on commercial maize-soybean based diets and birds from the wild whose diet was obtained from the natural environment. All eggs were incubated in a commercial hatchery. Day-old chicks from both groups were sacrificed and dissected for antioxidant analysis. Fat soluble antioxidant concentrations of egg yolk and tissues were determined by HPLC. Total carotenoids, retinol, alpha-tocopherol, and total vitamin E concentration of wild egg yolks were significantly higher compared to yolks from farm-reared birds (p < 0.05). However, gamma tocopherol, and coenzyme Q(10) were not significantly different in the yolks of either wild or farmed birds (p > 0.05). The concentration of total carotenoids in all tissues of wild chukar one-day old partridges was significantly higher than in farmed one-day old chukar partridge tissues (p < 0.05). Alpha tocopherol, free-retinol, retinal-esters and total vitamin A were significantly higher in most tissues of wild chukar when compared to farmed chicks (p < 0.05). Coenzyme Qio concentrations of heart, kidney and brain tissues of farm-reared chukar day old chicks were significantly higher than tissues from wild birds, although leg and breast tissues of wild chicks were significantly higher than in farmed birds (p < 0.05). These findings suggest that maternal access to antioxidants in the diet of farmed chukar partridges could positively influence fat soluble antioxidant concentrations in the egg yolk and tissues of day old chicks.
Condition Dependence of Nestling Mouth Colour and the Effect of Supplementing Carotenoids on Parental Behaviour in the Hihi (Notiomystis Cincta)
(Springer, 2008) Ewen, John G.; Thorogood, Rose; Karadas, Filiz; Cassey, Phillip
Carotenoids are integument pigments that often reflect foraging efficiency, disease resistance and body condition. In contrast to the widespread attention this relationship has received in adult birds, the condition dependence of nestling colouration remains an understudied component of animal communication. Here we assess the condition dependence of carotenoid pigmentation in nestling hihi (Notiomystis cincta, an endangered New Zealand bird) and examine the influence of carotenoid supplementation on nestling quality and parental visitation rates. Our results show that carotenoids provided to breeding adult hihi were transferred to their offspring and resulted in an intensified orange-yellow flange colour. After accounting for carotenoid supplementation the parameter that most consistently explained variation in nestling flange colour was nestling tarsus length at 23 days, indicating condition dependence of this trait. We did not, however, detect direct effects of carotenoid supplementation on nestling mass or immune response (or any other fitness parameter measured). Carotenoid supplementation did, however, result in an increased paternal provisioning rate.
Determination of Gossypol Levels of Cottonseed Meal Produced in the Southeastern Anatolia Region
(2024) Karageçılı, Mehmet Resıt; Karadas, Filiz
The levels of free and total gossypol and the raw nutrient content (crude protein, crude oil, dry matter, crude ash, neutral detergent fiber, and acid detergent fiber) in cottonseed meals that are produced in Southeastern Anatolia were determined in the present study. Gossypol and raw nutrient content analyses were carried out by using the cottonseed meal samples obtained from 12 different cottonseed oil factories located in Diyarbakır, Şanlıurfa, Adıyaman, Batman, Mardin, and Gaziantep. As a result of the present study, free gossypol levels in the cottonseed meal samples were 1937, 1878, 1916, 1845, 1442, and 1528 mg/kg, respectively. The free gossypol contents in the cottonseed meal samples obtained from Diyarbakır, Şanlıurfa, Adıyaman, and Batman provinces were statistically significantly higher when compared to samples obtained from Mardin and Gaziantep (p0.05), except for Gaziantep, where the samples had significantly lower oil and significantly higher protein content (p
The Effect of Organic Selenium in Feeding of Ewes in Late Pregnancy on Selenium Transfer To Progeny
(Revista Brasileira Zootecnia Brazilian Journal Animal Sci, 2017) Erdogan, Sibel; Karadas, Filiz; Yilmaz, Ayhan; Karaca, Serhat
The objective of this study was to determine the effect of supplemented organic selenium at different levels to concentrate feed of Norduz ewes in late pregnancy on maternal serum, placenta, colostrum, and offspring serum concentrations. This study was conducted using two-year-old 35 Norduz ewes. Ewes were randomly assigned to one of three dietary treatments for 57 days prepartum and at the seven days postpartum. Group 1 was fed a standard pregnant sheep concentrate basal diet without any additional Se supplement (control). Experiment groups were fed diets supplemented with 0.150 mg/kg, 0.300 mg/kg, and 0.450 mg/kg organic selenium to the same basal diet. Results showed that addition of selenium to gestating ewe diets increased Se in serum after one week of feeding. Ewes supplemented with 0.300 and 0.450 mg/kg Se had increased placenta, serum, and colostrum Se levels compared with those fed the control diet (P<0.05). There was a strong positive correlation between placental and serum Se concentration in ewes. Colostrum Se increased linearly with dietary Se in the treatment groups. At birth, lamb serum Se ranged from 48.96 ng/mL to 195.52 ng/mL and was affected by the Se concentration of the ewe diets, which indicated placenta transfer of selenium from the dam. As selenium level increased in basal diet, an upward trend was observed in maternal free thyroxine concentration. Likewise, serum free triiodothyronine, free thyroxine, and immunoglobulin G concentrations of lambs from the three treatment groups were significantly greater than of the control lambs. As a result, selenium supplementation was important for maintaining Se and immunoglobulin G concentration in placenta, serum, and colostrum in ewes.
Effects of Egg Weight and in Ovo Injection of Α-Tocopherol on Chick Development, Hatching Performance, and Lipid-Soluble Antioxidant Concentrations in Quail Chick Tissues
(Copernicus Gesellschaft Mbh, 2018) Babacanoglu, Elif; Karagecili, Mehmet Resit; Karadas, Filiz
Lipid-soluble antioxidants can be more effective for chick development when provided via in ovo (IO) injection than when supplemented to the maternal diet. This study was conducted to evaluate the effects of egg weight (EW) and JO injection of alpha-tocopherol on chick development, hatching performance and lipid-soluble antioxidant concentrations in residual yolk sac (RYS), liver and brain tissues of quail chicks. Eggs were obtained from quail breeders at days 72 and 128 of age and incubated at 37.8 degrees C and 60 % relative humidity. Each egg was numbered and weighed prior to incubation, and the average EW of all eggs was 11.76 +/- 0.05 g. The eggs were divided into light (< 11.76 EW; EWL) and heavy (> 11.76 EW; EWH) groups (148 eggs per EW). Each EW group was divided into two IO groups: the control (non-injection) group and alpha-tocopherol group, in which 3.75 mg of alpha-tocopherol per egg was injected into the yolk sac followed by a 120 h incubation period. There were 64 eggs for each EW-IO treatment combination (16 eggs per EW per tray). The chick and RYS weights were significantly lower in the EWL group than in the EWH group. A significant EW by IO interaction suggested that IO increased the eggshell temperature of light quail eggs. The non-injected light eggs had a shorter hatching time due to the interaction of EW with IO. Hatchability, embryonic mortalities, and the cumulative hatching rate were not affected by EW or IO. The chick and middle toe lengths increased following IO administration (P < 0.05), which indicated that IO administration had positive effects on chick quality. However, shank length decreased following IO administration with an unchanged relative asymmetry (RA). IO significantly affected the absolute weights of the liver and heart and the relative weight of the heart, which was lower in the alpha-tocopherol group than in the control group. IO administration had no effect on total retinol and carotenoid concentrations in the RYS, liver and brain. Vitamin E, alpha-tocopherol and delta-tocopherol concentrations in the RYS, liver and brain were significantly higher in the alpha-tocopherol-treated chicks than in the control chicks. The highest brain alpha-tocopherol concentration was found in the alpha-tocopherol-treated chicks of the EWH group, indicating a significant interaction between EW and IO. The highest total lipid-soluble antioxidant concentrations were obtained following IO alpha-tocopherol treatment (P < 0.05), in the order brain < liver < RYS, but this pattern was not observed with delta-tocopherol. In conclusion, IO injection of alpha-tocopherol into the yolk sac affected the concentrations of tissue-specific lipid-soluble antioxidants in the RYS and tissues of newly hatched quail chicks, and EW had effects on various parameters.
Effects of Maternal Dietary Supplementation With Three Sources of Carotenoids on the Retinyl Esters of Egg Yolk and Developing Quail Liver (Vol 140, Pg 430, 2006)
(Elsevier Science inc, 2007) Karadas, Filiz; Surai, Peter F.; Sparks, Nick H. C.; Grammenidis, Evangelos
Evidence for Genetic Hybridization Between Released and Wild Game Birds: Phylogeography and Genetic Structure of Chukar Partridge, Alectoris Chukar, in Turkey
(Mdpi, 2022) Albayrak, Tamer; Davila Garcia, Jose Antonio; Ozmen, Ozlem; Karadas, Filiz; Ates, Duygu; Wink, Michael
The Chukar Partridge (Alectoris chukar, Galliformes) is one of the most important game birds in its native range, spanning from the Balkans to eastern Asia, and the regions of Europe, North America and New Zealand where it was introduced. Previous studies found two main genetic lineages of the species forming an eastern and a western clade. Chukar Partridges are raised in game farms and released to supplement natural populations for shooting in the USA, Canada, Greece, and Turkey. To explore intraspecific genetic structure, phylogeography, and possible genetic admixture events of A. chukar in Turkey, we genotyped individuals from fourteen wild and five captive populations at two mitochondrial and ten microsatellite DNA loci in. Wild and farmed Chukar Partridge samples were analyzed together to investigate possible influences of intraspecific hybridizations. We found that the farmed chukars, which mainly (85%) cluster into the eastern clade, and wild ones were genetically distinct. The latter could be separated into six management units (MUs), with partridges from Gokceada Island in the Aegean Sea forming the most divergent population. Intraspecific hybridization was detected between wild and captive populations. This phenomenon causes rampant introgression and homogenization. The phylogeographic analysis revealed admixture among wild populations; nevertheless, this did not impair pointing to Anatolia as likely having a "refugia-within-refugia" structure. We recommend that the genetic structure of Chukar Partridge and its MUs be taken into account when developing the policy of hunting, production, and release to preserve the genetic integrity of this species.
Foraging for Carotenoids: Do Colorful Male Hihi Target Carotenoid-Rich Foods in the Wild
(Oxford Univ Press inc, 2014) Walker, Leila K.; Thorogood, Rose; Karadas, Filiz; Raubenheimer, David; Kilner, Rebecca M.; Ewen, John G.
Dietary access to carotenoids is expected to determine the strength of carotenoid-based signal expression and potentially to maintain signal honesty. Species that display carotenoid-based yellow, orange, or red plumage are therefore expected to forage selectively for carotenoid-rich foods when they are depositing these pigments during molt, but whether they actually do so is unknown. We set out to address this in the hihi (Notiomystis cincta), a New Zealand passerine where males, but not females, display yellow carotenoid-based plumage. We measured circulating carotenoid concentrations in male and female hihi during breeding and molt, determined the nutritional content of common foods in the hihi diet, and conducted feeding observations of male and female hihi during molt. We found that although male and female hihi do not differ significantly in plasma carotenoid concentration, male hihi have a greater proportion of carotenoid-rich foods in their diet than do females. This is a consequence of a greater fruit and lower invertebrate intake than females and an avoidance of low-carotenoid content fruit. By combining behavioral observations with quantification of circulating carotenoids, we present evidence that colorful birds forage to maximize carotenoid intake, a conclusion we would not have drawn had we examined plasma carotenoids alone.
High Levels of Liver Antioxidants Are Associated With Life-History Strategies Characteristic of Slow Growth and High Survival Rates in Birds
(Springer Heidelberg, 2012) Galvan, Ismael; Erritzoe, Johannes; Karadas, Filiz; Moller, Anders P.
Antioxidants have a large potential to coevolve with life-histories because of their capacity to counteract the negative effects of free radicals on fitness. However, only a few studies have explored the association between antioxidant levels and life-history strategies comparing a large number of species. Here we used an extensive dataset of 125 species of birds to investigate the association between concentrations of antioxidants (carotenoids and vitamin E) in the liver, which is the main storage organ for fat-soluble antioxidants, and life-history and morphology. We found that high liver antioxidant concentrations were associated with life-history strategies characterized by "live slow, die old", in clear contrast to previous studies reporting a relationship between high plasma antioxidants and life-histories characterized by "live fast, die young". Thus, high carotenoid concentrations were present in species with large body, brain and egg sizes, high absolute metabolic rate and a resident lifestyle, while high vitamin E concentrations were present in species with large brain size and long life span and incubation period. Our results indicate that antioxidants and life-histories coevolve, and that this may be mediated by positive fitness consequences of the accumulation of liver antioxidants, as species with higher antioxidant levels live longer.
Interspecies Variation in Yolk Selenium Concentrations Among Eggs of Free-Living Birds: the Effect of Phylogeny
(Elsevier Gmbh, Urban & Fischer verlag, 2006) Pappas, Athanasios C.; Karadas, Filiz; Surai, Peter F.; Wood, Nicholas A. R.; Cassey, Phillip; Bortolotti, Gary R.; Speake, Brian K.
Birds deposit the trace element selenium (Se) into their eggs because an adequate supply of this micronutrient is essential for embryonic development. Although there is considerable interest in egg Se with regard to topics as diverse as poultry nutrition and environmental pollution, data on the natural levels of Se in eggs of free-living avian species are currently very limited. To address this lack of information, we measured the yolk Se concentrations in eggs of 14 avian species collected in the wild. The concentrations (ng/g wet yolk) varied from 394 to 2238, with a mean value of 1040. Values (means +/- SD) for eggs from the UK, Canada and New Zealand were, respectively, 522 +/- 192 (3 species), 1194 +/- 584 (8 species) and 1147 +/- 200 (3 species). However, analysis by appropriate statistical models indicates that the effect of phylogenetic relatedeness among these species is so significant that it removes any effect of geographical location. In particular, species belonging to the order Passeriformes displayed significantly higher yolk Se levels than Non-Passeriforme species. In marked contrast to the free-living species, our previously published data indicate that the Se concentration in egg yolk of the domestic chicken is only about 100 ng/g wet yolk when the birds are maintained on a basal commercial diet without supplementary Se. The results reveal an extensive interspecies variation in yolk Se (across a 6-fold range) for eggs collected from the wild. Nevertheless, the Se concentrations in the yolks of all the free-living species were far higher (4-21-fold) than that achieved in the yolk of the domestic chicken consuming a standard basal diet. (c) 2006 Elsevier GrnbH. All rights reserved.
Is Oxidative Status Influenced by Dietary Carotenoid and Physical Activity After Moult in the Great Tit (Parus Major)
(Company Biologists Ltd, 2015) Vaugoyeau, Marie; Decenciere, Beatriz; Perret, Samuel; Karadas, Filiz; Meylan, Sandrine; Biard, Clotilde
In the context of sexual and natural selection, an allocation trade-off for carotenoid pigments may exist because of their obligate dietary origin and their role both in the antioxidant and immune systems and in the production of coloured signals in various taxa, particularly birds. When birds have expended large amounts of carotenoids to feather growth such as after autumn moult, bird health and oxidative status might be more constrained. We tested this hypothesis in a bird species with carotenoid-based plumage colour, by manipulating dietary carotenoids and physical activity, which can decrease antioxidant capacity and increase reactive oxygen metabolite (ROM) concentration. Great tits were captured after moult and kept in aviaries, under three treatments: physical handicap and dietary supplementation with carotenoids, physical handicap and control diet, and no handicap and control diet. We measured plasma composition (antioxidant capacity, ROM concentration, and vitamin A, vitamin E and total carotenoid concentrations), immune system activation (blood sedimentation) and stress response (heterophil/lymphocyte ratio) and predicted that handicap treatment should influence these negatively and carotenoid supplementation positively. Coloration of yellow feathers was also measured. Carotenoid supplementation increased total plasma carotenoid concentration, decreased feather carotenoid chroma and marginally increased ROM concentration. Handicap increased blood sedimentation only in males but had no clear influence on oxidative stress, which contradicted previous studies. Further studies are needed to investigate how physical activity and carotenoid availability might interact and influence oxidative stress outside the moult period, and their combined potential influence on attractiveness and reproductive investment later during the breeding season.
Levels of Antioxidants in Rural and Urban Birds and Their Consequences
(Springer, 2010) Moller, Anders Pape; Erritzoe, Johannes; Karadas, Filiz
Numerous animals have successfully invaded urban habitats, although the factors associated with invasion success remain poorly understood. Urban areas are characterized by warmer microclimates, higher levels of primary productivity, longer breeding seasons and higher levels of pollutants. All these factors should cause oxidative stress, favoring invasion by species that have access to high levels of antioxidants. We analyzed concentrations of two categories of dietary, fat-soluble antioxidants (total carotenoids, total vitamin E) in the liver, the main storage organ in birds. Individuals killed by cats had lower levels of vitamin E than individuals that died for other reasons, showing natural selection on stored antioxidants. Bird species that had successfully colonized urban areas had significantly higher levels of vitamin E and total carotenoids than species that did not succeed, and rural populations had higher concentrations of vitamin E and total carotenoids than urban populations of the same species. Interspecific differences in concentrations of fat-soluble antioxidants, and differences between rural and urban populations of the same species, were accounted for by diet, but also by time since urbanization and number of generations since urbanization. These findings suggest that antioxidants, and by implication the ability to cope with oxidative stress, have contributed to successful invasion of urban areas by birds, and that the concentration of these antioxidants has changed in response to the urban environment.
Liver Antioxidants in Relation To Beak Morphology, Gizzard Size and Diet in the Common Eider Somateria Mollissima
(Mdpi, 2019) Moller, Anders Pape; Laursen, Karsten; Karadas, Filiz
Antioxidants in the liver are particularly abundant in capital breeders that rely on stored resources for egg production. Capital breeders like eider (hereafter common eider) Somateria mollissima have disproportionately large livers with low levels of coenzyme Q(10) when compared to other bird species. Concentrations of total carotenoids and vitamin E in the livers of eiders were smaller than predicted for similarly sized bird species. Eiders with high body condition estimated as body mass relative to skeletal body size had high levels of total carotenoids and low levels of coenzyme Q(10). The concentration of total carotenoids per gram of liver increased with age, and vitamin E and total carotenoids accumulated during the winter onwards from February to peak at the start of incubation in April. Total vitamin E, total carotenoids, and coenzyme Q(10) per gram of liver decreased with increasing beak volume. The size of the empty gizzard increased with increasing liver mass but decreased with total carotenoids and coenzyme Q(10). The main components of the diet were blue mussels Mytilus edulis (40%), draft whelk Nassarius reticulatus (27%), and periwinkle Littorina littorea (10%). The concentration of vitamin E increased with the number of razor clams Ensis sp. and draft whelks in the gizzard and the concentration of total carotenoids increased with the number of beach crabs Carcinus maenas. These observations are consistent with the hypothesis that eiders are limited in their levels of antioxidants through food limitation. Furthermore, they imply that diet and morphological characters involved in food acquisition and processing are important determinants of the level of antioxidants in the liver.
Maternal Effects and Changing Phenology of Bird Migration
(inter-research, 2011) Moller, Anders Pape; Biard, Clotilde; Karadas, Filiz; Rubolini, Diego; Saino, Nicola; Surai, Peter F.
Recent changes in migration distances and propensity for migration associated with climate change have suggested that these traits can evolve rapidly. Part of this rapid response to selection may be due to maternal effects that facilitate changes in the underlying physiology of migration. We hypothesize that exposure to large amounts of antioxidants in the egg will facilitate assimilation and metabolism of dietary antioxidants later in life, thereby allowing offspring to better cope with extreme strenuous exercise such as the bursts of rapid migration shown during spring migration. We tested the relationship between temporal change in mean arrival date of migratory birds since 1960 and concentrations of 2 antioxidants in the eggs of 14 species of birds. Only egg concentration of vitamin E was a significant predictor of advancement in spring arrival date. Furthermore, we experimentally manipulated egg content of vitamin E in barn swallows Hirundo rustica and subsequently recorded arrival date of yearling male recruits. Arrival date advanced significantly by > 1 standard deviation due to treatment, providing experimental evidence for a relationship between egg concentration of vitamin E and subsequent migration behavior. These results are consistent with the hypothesis that maternal effects have played an important role in the evolution of bird migration.
Maternal Effects in the Highly Communal Sociable Weaver May Exacerbate Brood Reduction and Prepare Offspring for a Competitive Social Environment
(Springer, 2013) van Dijk, Rene E.; Eising, Corine M.; Merrill, Richard M.; Karadas, Filiz; Hatchwell, Ben; Spottiswoode, Claire N.
Maternal effects can influence offspring phenotype with short- and long-term consequences. Yet, how the social environment may influence egg composition is not well understood. Here, we investigate how laying order and social environment predict maternal effects in the sociable weaver, Philetairus socius, a species that lives in massive communal nests which may be occupied by only a few to 100+ individuals in a single nest. This range of social environments is associated with variation in a number of phenotypic and life-history traits. We investigate whether maternal effects are adjusted accordingly. We found no evidence for the prediction that females might benefit from modifying brood hierarchies through an increased deposition of androgens with laying order. Instead, females appear to exacerbate brood reduction by decreasing the costly production of yolk mass and antioxidants with laying order. Additionally, we found that this effect did not depend on colony size. Finally, in accordance with an expected increased intensity of environmental stress with increasing colony size, we found that yolk androgen concentration increased with colony size. This result suggests that females may enhance the competitive ability of offspring raised in larger colonies, possibly preparing the offspring for a competitive social environment.
Maternal Effects Mediated by Antioxidants and the Evolution of Carotenoid-Based Signals in Birds
(Univ Chicago Press, 2009) Biard, Clotilde; Gil, Diego; Karadas, Filiz; Saino, Nicola; Spottiswoode, Claire N.; Surai, Peter F.; Moller, Anders P.
Bright yellow to red signals used in mate choice or intrasexual competition are based on carotenoid pigments that are hypothesized to be traded between physiological functions and coloration. These signals have recently been shown to be influenced by maternal effects. Indeed, yolk-derived carotenoids are essential for embryos to develop efficient carotenoid metabolism in posthatching life. Maternal effects facilitate adaptation to environmental variability and influence the evolution of phenotypic traits such as secondary sexual signals. Here we propose that maternal investment in yolk carotenoids promotes the evolution of carotenoid-based ornaments. We conducted a comparative analysis of lipid-soluble antioxidants (carotenoids and vitamins A and E) in the eggs of 112 species of bird. Species with large clutch sizes deposited higher yolk concentrations of the three antioxidants. There was a significant positive relationship between yolk carotenoids and the expression of male carotenoid-based signals, but not between yolk carotenoids and sexual dichromatism in these signals. These relationships were specific to carotenoids, as they were not found for vitamins A and E. This provides evidence consistent with the hypothesis that maternal effects mediated by yolk carotenoids play a role in the evolution of carotenoid-based signals as a response to sexual selection, likely based on organizational effects of carotenoids during embryo development.
Maternal Effects Mediated by Egg Quality in the Yellow-Legged Gull Larus Michahellis in Relation To Laying Order and Embryo Sex
(Bmc, 2011) Rubolini, Diego; Romano, Maria; Navara, Kristen J.; Karadas, Filiz; Ambrosini, Roberto; Caprioli, Manuela; Saino, Nicola
Background: Maternal effects mediated by egg size and quality may profoundly affect offspring development and performance, and mothers may adjust egg traits according to environmental or social influences. In avian species, context-dependency of maternal effects may result in variation in egg composition, as well as in differential patterns of covariation among selected egg components, according to, for example, position in the laying sequence or offspring sex. We investigated variation in major classes of egg yolk components (carotenoids, vitamins and steroid hormones) in relation to egg size, position in the laying sequence and embryo sex in clutches of the Yellow-legged Gull (Larus michahellis). We also investigated their covariation, to highlight mutual adjustments, maternal constraints or trade-offs in egg allocation. Results: Laying sequence-specific patterns of allocation emerged: concentration of carotenoids and vitamin E decreased, while concentrations of androgens increased. Vitamin A, estradiol and corticosterone did not show any change. There was no evidence of sex-specific allocation or covariation of yolk components. Concentrations of carotenoids and vitamins were positively correlated. Egg mass decreased along the laying sequence, and this decrease was negatively correlated with the mean concentrations of carotenoids in clutches, suggesting that nutritionally constrained females lay low quality clutches in terms of carotenoid content. Finally, clutches with smaller decline in antioxidants between first-and last-laid eggs had a larger increase in yolk corticosterone, suggesting that a smaller antioxidant depletion along the laying sequence may entail a cost for laying females in terms of increased stress levels. Conclusions: Since some of the analyzed yolk components (e. g. testosterone and lutein) are known to exert sex-specific phenotypic effects on the progeny in this species, the lack of sex-specific egg allocation by mothers may either result from trade-offs between contrasting effects of different egg components on male and female offspring, or indicate that sex-specific traits are controlled primarily by mechanisms of sexual differentiation, including endogenous hormone production or metabolism of exogenous antioxidants, during embryonic development.