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Clairardin SG, Barnett CA, Sakaluk SK, Thompson CF. Experimentally increased in ovo testosterone leads to increased plasma bactericidal activity and decreased cutaneous immune response in nestling house wrens. J Exp Biol 2011; 214:2778-82. [DOI: 10.1242/jeb.054833] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
SUMMARY
Maternally derived testosterone in the eggs of birds may benefit nestlings by increasing various aspects of their growth, condition and behavioral development, but these benefits may come at a cost, including suppression of immune responsiveness. Experiments on a variety of species in which in ovo levels of testosterone have been experimentally increased have produced mixed results; some have found increased growth and suppressed immune function of nestlings whereas others have found the opposite. In an attempt to clarify the relationship between in ovo testosterone and nestling size, mass, health state and immune responsiveness, we experimentally increased levels of testosterone in the eggs of house wrens (Troglodytes aedon). We simultaneously determined the size, mass, hematocrit (a measure of health state), cutaneous immune response to phytohaemagglutinin and plasma bactericidal activity of nestlings near the time of fledging. We predicted that nestlings hatching from testosterone-injected eggs would exhibit lower immune responsiveness, but achieve greater mass, size and condition, than nestlings hatching from vehicle-injected control eggs. Instead, we found that nestlings hatching from testosterone-injected eggs had a weaker cutaneous immune response but greater bactericidal activity than those hatching from control eggs. They did not, however, differ significantly in mass, size or hematocrit from controls. These results suggest that experimentally increased in ovo testosterone induced a trade-off between bactericidal activity and the cutaneous immune response. The opposite responses by two different measures of immune function to experimentally increased in ovo testosterone underscore the importance of including multiple immune assays when investigating the potential for trade-offs with the immune system and other physiological functions.
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Affiliation(s)
- Sandrine G. Clairardin
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Craig A. Barnett
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Scott K. Sakaluk
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Charles F. Thompson
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
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52
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Ho DH, Reed WL, Burggren WW. Egg yolk environment differentially influences physiological and morphological development of broiler and layer chicken embryos. ACTA ACUST UNITED AC 2011; 214:619-28. [PMID: 21270311 DOI: 10.1242/jeb.046714] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Maternal effects are important in epigenetic determination of offspring phenotypes during all life stages. In the chicken (Gallus gallus domesticus), transgenerational transfer of egg yolk factors may set the stage for morphological and physiological phenotypic differences observed among breeds. To investigate the effect of breed-specific yolk composition on embryonic broiler and layer chicken phenotypes, we employed an ex ovo, xenobiotic technique that allowed the transfer of broiler and layer chicken embryos from their natural yolks to novel yolk environments. Embryonic day two broiler embryos developing on broiler yolk culture medium (YCM) had significantly higher heart rates than layer embryos developing on layer YCM (176±7 beats min(-1) and 147±7 beats min(-1), respectively). Broiler embryos developing on layer YCM exhibited heart rates typical of layer embryos developing normally on layer YCM. However, layer embryo heart rates were not affected by development on broiler YCM. Unlike O(2) consumption, development rate and body mass of embryos were significantly affected by exposure to different yolk types, with both broiler and layer embryos displaying traits that reflected yolk source rather than embryo genotype. Analysis of hormone concentrations of broiler and layer egg yolks revealed that testosterone concentrations were higher in broiler yolk (4.63±2.02 pg mg(-1) vs 3.32±1.92 pg mg(-1)), whereas triiodothyronine concentrations were higher in layer yolk (1.05±0.18 pg mg(-1) vs 0.46±0.22 pg mg(-1)). Thus, a complex synergistic effect of breed-specific genotype and yolk environment exists early in chicken development, with yolk thyroid hormone and yolk testosterone as potential mediators of the physiological and morphological effects.
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Affiliation(s)
- Dao H Ho
- Department of Biological Sciences, University of North Texas, Denton, TX 76203-5017, USA.
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53
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Okuliarova M, Kostal L, Zeman M. Effects of divergent selection for yolk testosterone content on growth characteristics of Japanese quail. Comp Biochem Physiol A Mol Integr Physiol 2011; 160:81-6. [PMID: 21627997 DOI: 10.1016/j.cbpa.2011.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/13/2011] [Accepted: 05/13/2011] [Indexed: 10/18/2022]
Abstract
Effects of yolk androgens on postnatal growth of offspring have been widely studied but their physiological role in the growth control is not fully understood due to an inconsistency in obtained results. We investigated androgen-mediated maternal effects on postnatal growth in relation to endocrine control mechanisms using two lines of Japanese quail divergently selected for high (HET) and low (LET) egg testosterone (T) content. Embryonic growth did not differ between the lines. During the growth period HET quail were heavier and displayed longer tarsi as compared with LET quail, with more pronounced line differences in males than females. HET males were heavier than LET males from the age of 2 weeks, reached the age of maximum growth rate earlier, and displayed higher asymptotic body weight than LET males. Accelerated growth in HET males was not accompanied by increased postembryonic plasma T concentrations. Plasma triiodothyronine levels did not differ between lines while plasma thyroxine levels were decreased in HET as compared with LET female chicks. Line differences in body weight disappeared in adult quail suggesting that yolk androgens, increased in a physiological way, resulted in stimulation of juvenile growth rate in precocial Japanese quail under stable social and environmental conditions.
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Affiliation(s)
- Monika Okuliarova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
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54
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Poisbleau M, Demongin L, Chastel O, Eens M, Quillfeldt P. Yolk androgen deposition in rockhopper penguins, a species with reversed hatching asynchrony. Gen Comp Endocrinol 2011; 170:622-8. [PMID: 21130090 DOI: 10.1016/j.ygcen.2010.11.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 07/28/2010] [Accepted: 11/26/2010] [Indexed: 11/29/2022]
Abstract
To maximize fitness, females should invest optimally in the siblings within a litter or brood and adapt this investment to environmental conditions. Chick mass and yolk androgens have been shown to influence the outcome of sibling competition. In birds, asynchronous hatching plays a major role in this process and often leads to brood reduction. We studied maternal deposition of yolk androgens in eggs of southern rockhopper penguins (Eudyptes chrysocome chrysocome). Contrary to other avian models, laying and hatching sequences do not coincide in this species, which exhibits reversed hatching asynchrony. This provides a unique model to test whether the first egg to hatch (B-egg), which is the most likely to survive, differs in composition from the second egg to hatch (A-egg). We found that B-eggs had higher egg masses, yolk masses, yolk androgen concentrations and total yolk androgen amounts than A-eggs. This was observed consistently for the three androgens analyzed (testosterone, androstenedione and 5α-dihydrotestosterone). Laying date affected androgen deposition into A- and B-eggs differently. Interestingly, late clutches had proportionally higher androgen levels in the B-egg compared to the A-egg than early clutches. We discuss these results in relation to the chronology of egg formation and the potential effect of the observed differences on embryo development and brood reduction.
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Affiliation(s)
- M Poisbleau
- Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Schlossallee 2, 78315 Radolfzell, Germany.
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55
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Guibert F, Richard-Yris MA, Lumineau S, Kotrschal K, Guémené D, Bertin A, Möstl E, Houdelier C. Social instability in laying quail: consequences on yolk steroids and offspring's phenotype. PLoS One 2010; 5:e14069. [PMID: 21124926 PMCID: PMC2989911 DOI: 10.1371/journal.pone.0014069] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 11/02/2010] [Indexed: 12/01/2022] Open
Abstract
Individual phenotypic characteristics of many species are influenced by non-genetic maternal effects. Female birds can influence the development of their offspring before birth via the yolk steroid content of their eggs. We investigated this prenatal maternal effect by analysing the influence of laying females' social environment on their eggs' hormonal content and on their offspring's development. Social instability was applied to groups of laying Japanese quail females. We evaluated the impact of this procedure on laying females, on yolk steroid levels and on the general development of chicks. Agonistic interactions were more frequent between females kept in an unstable social environment (unstable females) than between females kept in a stable social environment (stable females). Testosterone concentrations were higher in unstable females' eggs than in those of stable females. Unstable females' chicks hatched later and developed more slowly during their first weeks of life than those of stable females. The emotional reactivity of unstable females' chicks was higher than that of stable females' chicks. In conclusion, our study showed that social instability applied to laying females affected, in a non-genetic way, their offspring's development, thus stressing the fact that females' living conditions during laying can have transgenerational effects.
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Affiliation(s)
- Floriane Guibert
- UMR 6552 Ethologie animale et humaine, CNRS-Université de Rennes 1, Rennes, France.
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56
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Verboven N, Monaghan P, Nager RG, Evans NP. The Effect of Maternal State on the Steroid and Macronutrient Content of Lesser Black-Backed Gull Eggs. Physiol Biochem Zool 2010; 83:1009-22. [DOI: 10.1086/656568] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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57
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Kozlowski CP, Ricklefs RE. Egg size and yolk steroids vary across the laying order in cockatiel clutches: a strategy for reinforcing brood hierarchies? Gen Comp Endocrinol 2010; 168:460-5. [PMID: 20600043 DOI: 10.1016/j.ygcen.2010.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 04/20/2010] [Accepted: 06/14/2010] [Indexed: 11/18/2022]
Abstract
When a female bird begins incubation before clutch completion, the nestlings hatch sequentially, and a size hierarchy forms within the brood. This size hierarchy may be minimized or exacerbated through differential allocation of resources to eggs across the laying order. In this study, we characterize intra-clutch variation in cockatiel clutches by measuring egg mass, yolk mass, and concentrations of yolk testosterone, androstenedione, and corticosterone. Cockatiels are a long-lived member of the Psittaciformes. Because asynchronous hatching may reduce sibling competition and allow for extended development periods in long-lived birds, we predicted that female cockatiels would allocate maternal resources in a way that would reinforce the brood size hierarchy. Significant within-clutch differences in egg size and steroid concentrations were observed. Eggs at the end of the laying sequence were smaller and had significantly smaller yolks than eggs early in the laying order. Fifth-laid eggs, as well as first-laid eggs, contained significantly lower concentrations of testosterone than eggs in other positions of the laying sequence. No differences in yolk androstenedione concentration were observed. Yolk corticosterone concentrations increased linearly with laying order. Together, these patterns might reinforce the brood size hierarchy created by asynchronous hatching.
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Affiliation(s)
- Corinne P Kozlowski
- Research Department, Saint Louis Zoo, 1 Government Drive, St Louis, MO 63110, USA.
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58
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Garcia-Fernandez V, Amy M, Lacroix A, Malacarne G, Leboucher G. Eavesdropping on Male Singing Interactions Leads to Differential Allocation in Eggs. Ethology 2010. [DOI: 10.1111/j.1439-0310.2010.01784.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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59
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Elevated testosterone levels affect female breeding success and yolk androgen deposition in a passerine bird. Behav Processes 2009; 82:312-8. [DOI: 10.1016/j.beproc.2009.07.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 07/22/2009] [Accepted: 07/26/2009] [Indexed: 11/21/2022]
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60
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Partecke J, Schwabl H. Organizational effects of maternal testosterone on reproductive behavior of adult house sparrows. Dev Neurobiol 2009; 68:1538-48. [PMID: 18814315 DOI: 10.1002/dneu.20676] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Despite the well-known, long-term, organizational actions of sex steroids on phenotypic differences between the sexes, studies of maternal steroids in the vertebrate egg have mainly focused on effects seen in early life. Long-term organizational effects of yolk hormones on adult behavior and the underlying mechanisms that generate them have been largely ignored. Using an experiment in which hand-reared house sparrows (Passer domesticus) from testosterone- or control-treated eggs were kept under identical conditions, we show that testosterone treatment in the egg increased the frequency of aggressive, dominance, and sexual behavior of 1-year-old, reproductively competent house sparrows. We also show that circulating plasma levels of progesterone, testosterone, 5alpha-dihydrotestosterone, and 17beta-estradiol did not differ between treatment groups. Thus, a simple change in adult gonadal hormone secretion is not the primary physiological cause of long-term effects of maternal steroids on adult behavior. Rather, differences in adult behavior caused by exposure to yolk testosterone during embryonic development are likely generated by organizational modifications of brain function. Furthermore, our data provide evidence that hormone-mediated maternal effects are an epigenetic mechanism causing intra-sexual variation in adult behavioral phenotype.
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Affiliation(s)
- Jesko Partecke
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236, USA.
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61
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Schmidt J, Cole C, Zanes R, Satterlee D. Length of incubation and hatchling body weight in quail selected for reduced or exaggerated adrenocortical responsiveness to brief restraint. Br Poult Sci 2009; 50:266-71. [DOI: 10.1080/00071660802710140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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62
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Dor R, Lotem A. HERITABILITY OF NESTLING BEGGING INTENSITY IN THE HOUSE SPARROW (PASSER DOMESTICUS). Evolution 2009; 63:738-48. [DOI: 10.1111/j.1558-5646.2008.00598.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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63
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Egg composition in relation to social environment and maternal physiological condition in the collared flycatcher. Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0727-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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64
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Müller W, Vergauwen J, Eens M. Long-lasting consequences of elevated yolk testosterone levels on female reproduction. Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0714-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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65
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Soma M, Hiraiwa-Hasegawa M, Okanoya K. Early ontogenetic effects on song quality in the Bengalese finch (Lonchura striata var. domestica): laying order, sibling competition, and song syntax. Behav Ecol Sociobiol 2008. [DOI: 10.1007/s00265-008-0670-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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66
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Cortinovis S, Galassi S, Melone G, Saino N, Porte C, Bettinetti R. Organochlorine contamination in the Great Crested Grebe (Podiceps cristatus): effects on eggshell thickness and egg steroid levels. CHEMOSPHERE 2008; 73:320-325. [PMID: 18644614 DOI: 10.1016/j.chemosphere.2008.05.071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 05/16/2008] [Accepted: 05/27/2008] [Indexed: 05/26/2023]
Abstract
Eggs of the Great Crested Grebe (Podiceps cristatus) were collected from a breeding area on Lake Maggiore (Northern Italy) from 2001 to 2005 in the vicinity of a p,p'-DDT manufacturer, whose production was stopped in 1996. DDT homologue and PCB congener levels were determined and compared to levels in eggs collected from other breeding areas on Lake Maggiore and in a presumably less contaminated area on Lake Garda. Although Lake Garda eggs on average possessed a lower level of p,p'-DDE than Lake Maggiore eggs, they had significantly higher levels of PCBs and could not be used as a reference population for the measurement of eggshell thickness. Nevertheless, a negative linear relationship was found between p,p'-DDE concentration and eggshell thickness for eggs collected from both lakes, indicating a possible causal relationship. Testosterone and 17beta-estradiol concentrations were also determined for eggs collected from both lakes in 2004. Average concentrations of both hormones were the lowest in eggs from Lake Maggiore; however, the very high variability within broods did not result in any significant difference between the lakes.
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Affiliation(s)
- Serena Cortinovis
- Department of Biology, University of Milan, Via Celoria 26, 20133 Milano, Italy
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67
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Alonso-Alvarez C, Pérez-Rodríguez L, Mateo R, Chastel O, Viñuela J. The oxidation handicap hypothesis and the carotenoid allocation trade-off. J Evol Biol 2008; 21:1789-97. [PMID: 18713241 DOI: 10.1111/j.1420-9101.2008.01591.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxidation handicap hypothesis proposes that testosterone mediates the trade-off between the expression of secondary sexual traits and the fight against free radicals. Coloured traits controlled by testosterone can be produced by carotenoid pigments (yellow-orange-red traits), but carotenoids also help to quench free radicals. Recently, it has been shown that testosterone increases the amount of circulating carotenoids in birds. Here, a testosterone-mediated trade-off in the carotenoid allocation between colour expression and the fight against oxidative stress is proposed. Male red-legged partridges were treated with testosterone, anti-androgens or manipulated as controls. Testosterone-treated males maintained the highest circulating carotenoid levels, but showed the palest red traits and no evidence of oxidative damage. Increased levels of a key intracellular antioxidant (i.e. glutathione) indicated that an oxidative challenge was in fact induced but controlled. The trade-off was apparently solved by reducing redness, allowing increased carotenoid availability, which could have contributed to buffer oxidative stress.
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Affiliation(s)
- C Alonso-Alvarez
- Instituto de Investigación en Recursos Cinegéticos, IREC, CSIC, UCLM, JCCM, Ciudad Real, Spain.
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68
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Navara KJ, Mendonça MT. Yolk androgens as pleiotropic mediators of physiological processes: A mechanistic review. Comp Biochem Physiol A Mol Integr Physiol 2008; 150:378-86. [DOI: 10.1016/j.cbpa.2008.05.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 05/01/2008] [Accepted: 05/02/2008] [Indexed: 01/01/2023]
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69
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López-Rull I, Miksik I, Gil D. Egg pigmentation reflects female and egg quality in the spotless starling Sturnus unicolor. Behav Ecol Sociobiol 2008. [DOI: 10.1007/s00265-008-0617-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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70
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71
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Tschirren B, Richner H. Differential effects of yolk hormones on maternal and paternal contribution to parental care. Anim Behav 2008. [DOI: 10.1016/j.anbehav.2008.01.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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72
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Groothuis TGG, Schwabl H. Hormone-mediated maternal effects in birds: mechanisms matter but what do we know of them? Philos Trans R Soc Lond B Biol Sci 2008; 363:1647-61. [PMID: 18048291 PMCID: PMC2606725 DOI: 10.1098/rstb.2007.0007] [Citation(s) in RCA: 305] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Over the past decade, birds have proven to be excellent models to study hormone-mediated maternal effects in an evolutionary framework. Almost all these studies focus on the function of maternal steroid hormones for offspring development, but lack of knowledge about the underlying mechanisms hampers further progress. We discuss several hypotheses concerning these mechanisms, point out their relevance for ecological and evolutionary interpretations, and review the relevant data. We first examine whether maternal hormones can accumulate in the egg independently of changes in hormone concentrations in the maternal circulation. This is important for Darwinian selection and female physiological trade-offs, and possible mechanisms for hormone accumulation in the egg, which may differ among hormones, are reviewed. Although independent regulation of plasma and yolk concentrations of hormones is conceivable, the data are as yet inconclusive for ovarian hormones. Next, we discuss embryonic utilization of maternal steroids, since enzyme and receptor systems in the embryo may have coevolved with maternal effect mechanisms in the mother. We consider dose-response relationships and action pathways of androgens and argue that these considerations may help to explain the apparent lack of interference of maternal steroids with sexual differentiation. Finally, we discuss mechanisms underlying the pleiotropic actions of maternal steroids, since linked effects may influence the coevolution of parent and offspring traits, owing to their role in the mediation of physiological trade-offs. Possible mechanisms here are interactions with other hormonal systems in the embryo. We urge endocrinologists to embark on suggested mechanistic studies and behavioural ecologists to adjust their interpretations to accommodate the current knowledge of mechanisms.
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Affiliation(s)
- Ton G G Groothuis
- Behavioural Biology, University of Groningen, 9750 AA Haren, The Netherlands.
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73
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Gil D, Bulmer E, Celis P, López-Rull I. Adaptive developmental plasticity in growing nestlings: sibling competition induces differential gape growth. Proc Biol Sci 2008; 275:549-54. [PMID: 18089540 DOI: 10.1098/rspb.2007.1360] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sibling competition has been shown to affect overall growth rates in birds. However, growth consists on the coordinated development of a multitude of structures, and there is ample scope for developmental plasticity and trade-offs among these structures. We would expect that the growth of structures that are used in sibling competition, such as the gape of altricial nestlings, should be prioritized under intense competition. We conducted an experiment in the spotless starling (Sturnus unicolor), cross-fostering nestlings to nests with different levels of sibling competition. We predicted that nestlings subjected to higher levels of sibling competition should develop larger gapes than control birds. We found that, halfway through the nestling period, overall size (a composite index of mass, wing, tarsus and bill) was reduced in nests with intense sibling competition, whereas gape width remained unaffected. At the end of the nestling period, experimental nestlings had wider gapes than controls. Additionally, a correlative study showed that nestling gape width increased when feeding conditions worsened and overall size decreased. These patterns could either be due to increased growth of gape flanges or to delayed reabsorption of this structure. Our results show that birds can invest differentially in the development of organs during growth, and that the growth of organs used in sibling competition is prioritized over structural growth.
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Affiliation(s)
- Diego Gil
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), José Gutierrez Abascal 2, 28006, Madrid, Spain.
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74
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Sex-specific costs of hatching last: an experimental study on herring gulls (Larus argentatus). Behav Ecol Sociobiol 2008. [DOI: 10.1007/s00265-008-0582-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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75
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Cucco M, Guasco B, Malacarne G, Ottonelli R, Tanvez A. Yolk testosterone levels and dietary carotenoids influence growth and immunity of grey partridge chicks. Gen Comp Endocrinol 2008; 156:418-25. [PMID: 18299130 DOI: 10.1016/j.ygcen.2007.12.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 12/18/2007] [Accepted: 12/25/2007] [Indexed: 10/22/2022]
Abstract
Early maternal effects in the form of substances accumulated in the egg, such as carotenoids and hormones, can be physiologically relevant for a good development of offspring. It has been found in different species that testosterone (T) can be beneficial to offspring by increasing growth rate, but detrimental by reducing immunocompetence and increasing oxidative stress. Carotenoids on the other hand are suggested to be beneficial because they can counteract the oxidative stress and the immune-depressive effect of T. In this study we analyzed the effect of prenatal T exposure in the grey partridge. We injected eggs with three doses of T (high, intermediate, and physiological). After hatching, chicks exposed to a prenatal high dose of T were fed with two diets (rich or poor) differing in beta-carotene content. We found a significant effect of T on both chick growth and cell-mediated immunity, with high T doses resulting in detrimental effects while low doses were beneficial. Detrimental effects of the high dose of T on immunity were mitigated by beta-carotene consumed in the diet. The differences between groups were observed in the early period of life (age 10 days for mass, and age 10 and 21 days for immunity), and disappeared in the following period, and up to 1 and 2 years later. Overall, our observations show that T in the egg is not detrimental but beneficial, and that negative effects are found only at supraphysiological concentrations. The negative effects of T on immunity could be balanced if chicks could consume a diet rich in beta-carotene.
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Affiliation(s)
- Marco Cucco
- University of Piemonte Orientale, DISAV Dipartimento di Scienze dell'Ambiente e della Vita, via Bellini 25, Alessandria, Italy.
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76
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Göth A, Eising CM, Herberstein ME, Groothuis TGG. Consistent variation in yolk androgens in the Australian Brush-turkey, a species without sibling competition or parental care. Gen Comp Endocrinol 2008; 155:742-8. [PMID: 18086471 DOI: 10.1016/j.ygcen.2007.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 10/03/2007] [Accepted: 11/06/2007] [Indexed: 11/16/2022]
Abstract
Maternal hormones are an excellent pathway for the mother to influence offspring development, and birds provide exceptional opportunities to study these hormone-mediated maternal effects. Two dominant hypotheses about the function of yolk androgens in avian eggs concern maternal manipulation of sibling competition and post hatching paternal care. In megapodes, however, neither sibling competition nor post hatching parental care exists. Eggs are incubated by external heat sources, and chicks dig themselves out of their underground nest and live independently of their parents and their siblings. In this first study on egg androgens of such a megapode, the Australian Brush-turkey Alectura lathami, we found nevertheless substantial amounts of maternal androgens. Since size of the incubation mound, incubation temperature, egg size and laying date greatly vary in this species, we analysed variation in testosterone (T), androstenedione (A4) and dihydrotestosterone (DHT) in relation to these factors. T concentrations were significantly higher in eggs from bigger mounds and laid at greater depth, which may compensate via anabolic effects for the longer duration and higher energetic requirements of chicks when digging themselves out. T concentrations were higher in smaller eggs, and both yolk A4 and T concentrations increased with laying date, perhaps as a compensatory measure, while DHT concentrations only varied across different mounds. These results indicate that maternal androgens may influence offspring development outside the contexts of sibling competition or parental care.
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Affiliation(s)
- Ann Göth
- Department of Biological Sciences, Macquarie University, North Ryde, Sydney NSW 2109, Australia.
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77
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Schmaltz G, Quinn JS, Schoech SJ. Do group size and laying order influence maternal deposition of testosterone in smooth-billed ani eggs? Horm Behav 2008; 53:82-9. [PMID: 17942099 DOI: 10.1016/j.yhbeh.2007.09.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 08/17/2007] [Accepted: 09/04/2007] [Indexed: 11/28/2022]
Abstract
The avian egg contains maternal hormones that affect behavior, growth, morphology, and offspring survival. Evidence to date suggests that patterns of yolk androgen deposition could provide females with a means to manipulate sibling competition and, thereby, increase their fitness. We examined yolk testosterone (T) concentrations in eggs of the smooth-billed ani (Crotophaga ani) to understand patterns of androgen deposition in eggs of this plural-breeding joint-nesting cooperatively breeding species. We tested the hatching asynchrony adjustment hypothesis, which states that increases in yolk androgen levels over the laying sequence function to mitigate the disadvantage of being a later-hatched chick in species without adaptive brood reduction. We also investigated the effect of group size on yolk T deposition to test the hypothesis that females in multi-female groups could give a competitive edge to their own chicks by depositing higher T levels in their eggs. Predictions of the hatching asynchrony adjustment hypothesis were supported in both single- and multi-female groups as yolk testosterone levels increased from early- to late-laid eggs. This suggests that ani females can influence nestling competition and chick survival by within-clutch differential T allocation. Unexpectedly, we did not observe an effect of group size on yolk T deposition. Yolk testosterone concentrations may not be a mere reflection of a female's hormonal status as female plasma circulating levels of T did not vary in the same direction as yolk T levels. Results of this study therefore support the idea that females may adaptively manipulate chick behavior through hormonal deposition in eggs.
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Affiliation(s)
- Gregory Schmaltz
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1
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78
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Gil D. Chapter 7 Hormones in Avian Eggs: Physiology, Ecology and Behavior. ADVANCES IN THE STUDY OF BEHAVIOR 2008. [DOI: 10.1016/s0065-3454(08)00007-7] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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79
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SNIVELY ERIC, RUSSELL ANTHONYP. Functional morphology of neck musculature in the Tyrannosauridae (Dinosauria, Theropoda) as determined via a hierarchical inferential approach. Zool J Linn Soc 2007. [DOI: 10.1111/j.1096-3642.2007.00334.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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80
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Radder RS, Shine R. Are the phenotypic traits of hatchling lizards affected by maternal allocation of steroid hormones to the egg? Gen Comp Endocrinol 2007; 154:111-9. [PMID: 17632106 DOI: 10.1016/j.ygcen.2007.05.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 05/14/2007] [Accepted: 05/26/2007] [Indexed: 10/23/2022]
Abstract
In lizards as in many other kinds of animals, strong maternal effects on the phenotypic traits of hatchlings are frequently reported. One plausible non-genetic mechanism that might produce such differences among clutches involves maternal allocation of steroid hormones. Lizard eggs often display considerable inter-clutch variation in the quantities of maternally allocated steroids, and exogenous application of such steroids has been reported to influence the phenotypic traits (especially, sex) of hatchlings. We examined correlations between naturally occurring yolk steroid levels and offspring traits in the scincid lizard Bassiana duperreyi, and also conducted experimental trials (exogenous application of testosterone or 17beta-oestradiol to eggs) to test for causal effects of hormones. Although exogenous hormones readily reversed sex of the hatchling lizards, no other phenotypic traits of the hatchlings (morphology, locomotor performance) were significantly correlated with naturally occurring levels of testosterone, dihydrotestosterone or estrogen, nor were these phenotypic traits significantly affected by exogenous application of hormones. Hence, our results do not support the hypothesis that reproducing female lizards manipulate the phenotypic traits of their offspring by differential allocation of steroid hormones.
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Affiliation(s)
- Rajkumar S Radder
- School of Biological Sciences A08, The University of Sydney, NSW 2006, Australia.
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81
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Are yolk androgens and carotenoids in barn swallow eggs related to parental quality? Behav Ecol Sociobiol 2007. [DOI: 10.1007/s00265-007-0470-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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82
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Maternally derived egg yolk steroid hormones and sex determination: Review of a paradox in reptiles. J Biosci 2007; 32:1213-20. [DOI: 10.1007/s12038-007-0123-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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83
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JAWOR JODIEM, MCGLOTHLIN JOELW, CASTO JOSEPHM, GREIVES TIMOTHYJ, SNAJDR ERICA, BENTLEY GEORGEE, KETTERSON ELLEND. Testosterone response to GnRH in a female songbird varies with stage of reproduction: implications for adult behaviour and maternal effects. Funct Ecol 2007. [DOI: 10.1111/j.1365-2435.2007.01280.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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84
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Gil D, Faure JM. Correlated response in yolk testosterone levels following divergent genetic selection for social behaviour in Japanese quail. ACTA ACUST UNITED AC 2007; 307:91-4. [PMID: 17171709 DOI: 10.1002/jez.a.340] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Maternal effects are a powerful tool that parents can use to modify the phenotype of their offspring. In birds, the amount of androgens that females deposit in their eggs has been shown to influence early development and adult behavioural phenotypes. Differences in such behavioural strategies have been used as the target of artificial selection programmes with a view to improve animal welfare. In this study, we tested whether artificial selection for divergent social behaviour in Japanese quail had resulted in correlated changes in yolk androgen levels. We used lines that had been selected at the chick stage for high and low motivation to regain contact with a group of conspecific chicks. This procedure has led to important behavioural differences in the high and low line in a suite of behavioural correlates of sociality. We found that eggs laid by the line selected for high motivation for social reinstatement contained more than twice the amount of yolk testosterone of eggs laid by females from the low line, while the unselected line laid eggs with intermediate levels. This finding strongly suggests a functional link between these two traits, and underlines the possible role of yolk androgen modulation in promoting the evolution of behavioural syndromes.
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Affiliation(s)
- Diego Gil
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), José Gutiérrez Abascal 2, E-28006 Madrid, Spain.
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85
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ALONSO-ALVAREZ CARLOS, BERTRAND SOPHIE, SORCI GABRIELE. Sex-specific transgenerational effects of early developmental conditions in a passerine. Biol J Linn Soc Lond 2007. [DOI: 10.1111/j.1095-8312.2007.00811.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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86
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Gil D, Biard C, Lacroix A, Spottiswoode CN, Saino N, Puerta M, Moller AP. Evolution of Yolk Androgens in Birds: Development, Coloniality, and Sexual Dichromatism. Am Nat 2007; 169:802-19. [PMID: 17479466 DOI: 10.1086/516652] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 09/20/2006] [Indexed: 11/03/2022]
Abstract
Current theory recognizes the adaptive value of maternal effects in shaping offspring phenotypes in response to selective pressures and vindicates the value of these traits in fostering adaptation and speciation. Yolk androgens in birds are a relatively well-known maternal effect and have been linked to adaptations related to development, coloniality life, and sexual selection. We tested whether interspecific patterns of yolk androgen levels (androstenedione and testosterone) were related to interspecific variation in development, sexual selection, and coloniality. First, we found no relationship between androgen levels and duration of development as reflected by incubation and nestling periods. However, androstenedione concentration was positively related to the relative duration of the incubation period and negatively related to the relative duration of the nestling period. These relationships were confirmed by analyses of phylogenetically independent contrasts. We suggest that androstenedione concentration may have evolved as a mechanism to shift the relative duration of development between the egg and nestling stages in response to selective pressures that differentially affect the duration of each stage. Second, neither plumage dichromatism nor mating system explained significant variation in yolk androgen levels after correction for similarity among species due to common descent. This finding indicates that sexual selection has not been an important selective pressure for this maternal effect. Third, we found a highly significant positive relationship between degree of breeding coloniality and concentration of androstenedione but not testosterone. These effects were confirmed in analyses of contrasts controlling for similarity due to common descent. Since the relationship with coloniality was different for each androgen, it is unlikely that increased levels of androgens in highly colonial species are a mere consequence of elevated androgen levels in mothers. Rather, our results suggest that high levels of androstenedione in eggs of colonial species are an adaptation to colony life, possibly related to the production of highly competitive phenotypes. In conclusion, from a comparative perspective, the results of this study support the role of maternal effects in promoting adaptation to certain environmental pressures.
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Affiliation(s)
- Diego Gil
- Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales (Consejo Superior de Investigaciones Cientificas), Jose Gutierrez Abascal 2, Madrid, Spain.
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87
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Food supply during prelaying period modifies the sex-dependent investment in eggs of Eurasian kestrels. Behav Ecol Sociobiol 2007. [DOI: 10.1007/s00265-007-0405-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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88
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Sex-specific maternal effect on egg mass, laying order, and sibling competition in the Bengalese finch (Lonchura striata var. domestica). Behav Ecol Sociobiol 2007. [DOI: 10.1007/s00265-007-0400-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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89
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Foster VS, Burley NT. Sex Allocation in Response to Maternal Condition: Different Tactics of Care-Giving by Male and Female Zebra Finches. Ethology 2007. [DOI: 10.1111/j.1439-0310.2007.01350.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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90
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Rubolini D, Martinelli R, von Engelhardt N, Romano M, Groothuis TG, Fasola M, Saino N. Consequences of prenatal androgen exposure for the reproductive performance of female pheasants (Phasianus colchicus). Proc Biol Sci 2007; 274:137-42. [PMID: 17018428 PMCID: PMC1679874 DOI: 10.1098/rspb.2006.3696] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Maternal hormones in vertebrate eggs can mediate important forms of maternal effects. However, the function of hormone transfer to the eggs is still debated, especially because long-term fitness consequences have been little studied. We investigated the effect of prenatal exposure to physiologically elevated yolk testosterone (T) levels on reproduction of female pheasants (Phasianus colchicus) in captivity. We found that females hatching from T-injected eggs (T-females) had a lower egg-laying rate than controls, and their eggs were more frequently infertile than those laid by control females. There were no effects of prenatal maternal treatment on egg size and yolk T concentration, but eggs carrying a female embryo laid by T-females had smaller yolks than eggs with a male embryo, while there was no sex difference in yolk size among the eggs laid by control females. Progeny sex ratio was unaffected by maternal treatment. These findings suggest that the transfer of high androgen levels to the eggs by the mother is constrained by complex trade-offs between direct effects on her daughters' reproduction and by trans-generational differential consequences on male and female descendants.
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Affiliation(s)
- Diego Rubolini
- Dipartimento di Biologia Animale, Università degli Studi di Paviapiazza Botta 9, 27100 Pavia, Italy
| | - Roberta Martinelli
- Dipartimento di Biologia, Università degli Studi di Milanovia Celoria 26, 20133 Milano, Italy
| | - Nikolaus von Engelhardt
- Department of Behavioural Biology, University of GroningenPO Box 14, 9750, AA Haren, The Netherlands
| | - Maria Romano
- Dipartimento di Biologia, Università degli Studi di Milanovia Celoria 26, 20133 Milano, Italy
| | - Ton G.G Groothuis
- Department of Behavioural Biology, University of GroningenPO Box 14, 9750, AA Haren, The Netherlands
| | - Mauro Fasola
- Dipartimento di Biologia Animale, Università degli Studi di Paviapiazza Botta 9, 27100 Pavia, Italy
| | - Nicola Saino
- Dipartimento di Biologia, Università degli Studi di Milanovia Celoria 26, 20133 Milano, Italy
- Author for correspondence ()
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91
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Radder R, Ali S, Shine R. Offspring Sex Is Not Related to Maternal Allocation of Yolk Steroids in the Lizard Bassiana duperreyi (Scincidae). Physiol Biochem Zool 2007; 80:220-7. [PMID: 17252518 DOI: 10.1086/510639] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2006] [Indexed: 11/03/2022]
Abstract
The eggs of birds and reptiles contain detectable levels of several steroid hormones, and experimental application of such steroids can reverse genetically determined sex of the offspring. However, any causal influence of maternally derived yolk steroids on sex determination in birds and reptiles remains controversial. We measured yolk hormones (dihydrotestosterone, testosterone, and 17 beta-estradiol) in newly laid eggs of the montane scincid lizard Bassiana duperreyi. This species is well suited to such an analysis because (1) offspring sex is influenced by incubation temperatures and egg size as well as by sex chromosomes, suggesting that yolk hormones might somehow be involved in the complex pathways of sex determination, and (2) experimental application of either estradiol or fadrozole to such eggs strongly influences offspring sex. We obtained yolk by biopsy, before incubating the eggs at a temperature that produces a 50:50 sex ratio. Yolk steroid levels varied over a threefold range between eggs from different clutches, but there were no significant differences in yolk steroids, or in relative composition of steroids, between eggs destined to become male versus female. Further, yolk steroid concentrations were not significantly related to egg size. Thus, yolk steroid hormones do not appear to play a critical role in sex determination for B. duperreyi.
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Affiliation(s)
- Rajkumar Radder
- School of Biological Sciences A08, University of Sydney, Sydney, New South Wales 2006, Australia
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92
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Carere C, Balthazart J. Sexual versus individual differentiation: the controversial role of avian maternal hormones. Trends Endocrinol Metab 2007; 18:73-80. [PMID: 17276694 DOI: 10.1016/j.tem.2007.01.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Revised: 01/03/2007] [Accepted: 01/24/2007] [Indexed: 11/24/2022]
Abstract
Avian embryos are exposed not only to endogenous sex steroids, which are produced by their gonads and have a key role in sexual differentiation, but also to maternal steroids transferred into the egg yolk, which can modulate the development of individual differences in behavior. Studies of maternal hormones have primarily focused on ultimate questions (evolutionary trade-offs, functional significance), whereas proximate mechanistic questions have been largely ignored. A central problem that must be addressed is how exposure to maternal hormones affects the individual phenotype without interfering with sexual differentiation. Separate effects could result from the action of different hormones, at different doses or at different times, on different targets.
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Affiliation(s)
- Claudio Carere
- Section of Behavioural Neurosciences, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
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93
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Gorman KB, Williams TD. Correlated evolution of maternally derived yolk testosterone and early developmental traits in passerine birds. Biol Lett 2007; 1:461-4. [PMID: 17148233 PMCID: PMC1626382 DOI: 10.1098/rsbl.2005.0346] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent studies on hormone-mediated maternal effects in birds have highlighted the influence of variable maternal yolk androgen concentration on offspring phenotype, particularly in terms of early development. If genetic differences between laying females regulate variation in yolk hormone concentration, then this physiological maternal effect is an indirect genetic effect which can provide a basis for the co-evolution of maternal and offspring phenotypes. Thus, we investigated the evolutionary associations between maternally derived yolk testosterone (T) and early developmental traits in passerine birds via a comparative, phylogenetic analysis. Our results from species-correlation and independent contrasts analyses provide convergent evidence for the correlated evolution of maternal yolk T concentration and length of the prenatal developmental period in passerines. Here, we show these traits are significantly negatively associated (species-correlation: p<0.001, r2=0.85; independent contrasts: p=0.005). Our results highlight the need for more studies investigating the role of yolk hormones in evolutionary processes concerning maternal effects.
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Affiliation(s)
- K B Gorman
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6.
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94
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Rutkowska J, Wilk T, Cichoń M. Androgen-dependent maternal effects on offspring fitness in zebra finches. Behav Ecol Sociobiol 2007. [DOI: 10.1007/s00265-007-0351-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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95
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Groothuis TG, Eising CM, Dijkstra C, Müller W. Balancing between costs and benefits of maternal hormone deposition in avian eggs. Biol Lett 2007; 1:78-81. [PMID: 17148133 PMCID: PMC1629043 DOI: 10.1098/rsbl.2004.0233] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Avian eggs contain substantial amounts of maternal androgens, and several studies have indicated that these are beneficial for the chick. Nevertheless, there is a large and systematic variation in maternal hormone concentrations both within and between clutches. If maternal androgens also involve costs, this might explain why not all mothers put high levels of androgens in their clutches. However, the simultaneous occurrence of both benefits and costs has not yet been convincingly demonstrated. We show experimentally that yolk androgens suppress immune function and simultaneously stimulate growth in black-headed gull chicks. Thus, mothers face a trade-off between these costs and benefits and may tune hormone deposition to prevailing conditions that influence chick survival.
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Affiliation(s)
- Tong G Groothuis
- Department of Animal Behaviour, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands.
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96
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Sockman KW, Sharp PJ, Schwabl H. Orchestration of avian reproductive effort: an integration of the ultimate and proximate bases for flexibility in clutch size, incubation behaviour, and yolk androgen deposition. Biol Rev Camb Philos Soc 2007. [DOI: 10.1111/j.1469-185x.2006.tb00221.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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97
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98
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Tschirren B, Fitze PS, Richner H. Maternal Modulation of Natal Dispersal in a Passerine Bird: An Adaptive Strategy to Cope with Parasitism? Am Nat 2007; 169:87-93. [PMID: 17206587 DOI: 10.1086/509945] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 08/08/2006] [Indexed: 11/03/2022]
Abstract
The decision of how far to disperse from the natal territory has profound and long-lasting consequences for young animals, yet the optimal dispersal behavior often depends on environmental factors that are difficult or impossible to assess by inexperienced juveniles. Natural selection thus favors mechanisms that allow the adaptive and flexible adjustment of the offspring's dispersal behavior by their parents via either paternal or maternal effects. Here we show that different dispersal strategies maximize the reproductive success of young great tits (Parus major) originating from a parasite-infested or a parasite-free nest and demonstrate that differential transfer of maternal yolk androgens in response to parasitism can result in a modification of the offspring's dispersal behavior that appears adaptive. It demonstrates that prenatal maternal effects are an important yet so far neglected determinant of natal dispersal and highlights the potential importance of maternal effects in mediating coevolutionary processes in host-parasite systems.
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Affiliation(s)
- Barbara Tschirren
- Evolutionary Ecology Group, Zoological Institute, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland.
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99
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Male sexual attractiveness affects the investment of maternal resources into the eggs in peafowl (Pavo cristatus). Behav Ecol Sociobiol 2006. [DOI: 10.1007/s00265-006-0337-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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100
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Carotenoids in the egg yolks of collared flycatchers (Ficedula albicollis) in relation to parental quality, environmental factors and laying order. Behav Ecol Sociobiol 2006. [DOI: 10.1007/s00265-006-0282-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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