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Sim S, Park CM, Lee SH, Cho H, Ji Y, Noh H, Lee SI. The effect of avian eggshell membrane structure on microbial penetration: A simulation study. Biosystems 2024; 240:105234. [PMID: 38759750 DOI: 10.1016/j.biosystems.2024.105234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/12/2024] [Accepted: 05/13/2024] [Indexed: 05/19/2024]
Abstract
Avian eggshells exhibit excellent antimicrobial properties. In this study, we conducted simulation experiments to explore the defense mechanisms of eggshell membranes with regards to their physical features. We developed a mathematical model for the movement of microorganisms and estimated their penetration ratio into eggshell membranes based on several factors, including membrane thickness, microbial size, directional drift, and attachment probability to membrane fibers. These results not only suggest that an eggshell membrane with multiple layers and low porosity indicates high antimicrobial performance, but also imply that the fibrous network structure of the membrane might contribute to effective defense. Our simulation results aligned with experimental findings, specifically in measuring the penetration time of Escherichia coli through the eggshell membrane. We briefly discuss the significance and limitations of this pilot study, as well as the potential for these results, to serve as a foundation for the development of antimicrobial materials.
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Affiliation(s)
- Seungwoo Sim
- Ecological Technology Research Team, National Institute of Ecology, Seocheon, Chungnam, South Korea.
| | - Cheol-Min Park
- Division of Industrial Mathematics, National Institute for Mathematical Sciences, Daejeon, South Korea
| | - Sang-Hee Lee
- Division of Industrial Mathematics, National Institute for Mathematical Sciences, Daejeon, South Korea
| | - Haeun Cho
- Laboratory of Behaviour and Ecology, Interdisciplinary Program of EcoCreative, Ewha Womans University, Seoul, South Korea
| | - Youngheum Ji
- School of Undergraduate Studies, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
| | - Heeso Noh
- Department of Nano and Electronic Physics, Kookmin University, Seoul, South Korea
| | - Sang-Im Lee
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
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Lopes PC, Gormally BMG, Emmi A, Schuerman D, Liyanage C, Beattie UK, Romero LM. Maternal Responses in the Face of Infection Risk. Integr Comp Biol 2022; 62:1584-1594. [PMID: 35675319 DOI: 10.1093/icb/icac082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/27/2022] [Accepted: 06/01/2022] [Indexed: 01/05/2023] Open
Abstract
When animals are sick, their physiology and behavior change in ways that can impact their offspring. Research is emerging showing that infection risk alone can also modify the physiology and behavior of healthy animals. If physiological responses to environments with high infection risk take place during reproduction, it is possible that they lead to maternal effects. Understanding whether and how high infection risk triggers maternal effects is important to elucidate how the impacts of infectious agents extend beyond infected individuals and how, in this way, they are even stronger evolutionary forces than already considered. Here, to evaluate the effects of infection risk on maternal responses, we exposed healthy female Japanese quail to either an immune-challenged (lipopolysaccharide [LPS] treated) mate or to a healthy (control) mate. We first assessed how females responded behaviorally to these treatments. Exposure to an immune-challenged or control male was immediately followed by exposure to a healthy male, to determine whether treatment affected paternity allocation. We predicted that females paired with immune-challenged males would avoid and show aggression towards those males, and that paternity would be skewed towards the healthy male. After mating, we collected eggs over a 5-day period. As an additional control, we collected eggs from immune-challenged females mated to healthy males. We tested eggs for fertilization status, embryo sex ratio, as well as albumen corticosterone, lysozyme activity, and ovotransferrin, and yolk antioxidant capacity. We predicted that immune-challenged females would show the strongest changes in the egg and embryo metrics, and that females exposed to immune-challenged males would show intermediate responses. Contrary to our predictions, we found no avoidance of immune-challenged males and no differences in terms of paternity allocation. Immune-challenged females laid fewer eggs, with an almost bimodal distribution of sex ratio for embryos. In this group, albumen ovotransferrin was the lowest, and yolk antioxidant capacity decreased over time, while it increased in the other treatments. No differences in albumen lysozyme were found. Both females that were immune-challenged and those exposed to immune-challenged males deposited progressively more corticosterone in their eggs over time, a pattern opposed to that shown by females exposed to control males. Our results suggest that egg-laying Japanese quail may be able to respond to infection risk, but that additional or prolonged sickness symptoms may be needed for more extensive maternal responses.
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Affiliation(s)
- Patricia C Lopes
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Brenna M G Gormally
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Aubrey Emmi
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Delilah Schuerman
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Chathuni Liyanage
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
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van Veelen HPJ, Salles JF, Matson KD, van Doorn GS, van der Velde M, Tieleman BI. The microbial environment modulates non-genetic maternal effects on egg immunity. Anim Microbiome 2022; 4:44. [PMID: 35902980 PMCID: PMC9331593 DOI: 10.1186/s42523-022-00195-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/29/2022] [Indexed: 11/10/2022] Open
Abstract
Background In a diverse microbial world immune function of animals is essential. Diverse microbial environments may contribute to extensive variation in immunological phenotypes of vertebrates, among and within species and individuals. As maternal effects benefit offspring development and survival, whether females use cues about their microbial environment to prime offspring immune function is unclear. To provide microbial environmental context to maternal effects, we asked if the bacterial diversity of the living environment of female zebra finches Taeniopygia guttata shapes maternal effects on egg immune function. We manipulated environmental bacterial diversity of birds and tested if females increased immunological investment in eggs in an environment with high bacterial diversity (untreated soil) versus low (gamma-sterilized soil). We quantified lysozyme and ovotransferrin in egg albumen and IgY in egg yolk and in female blood, and we used 16S rRNA gene sequencing to profile maternal cloacal and eggshell microbiotas. Results We found a maternal effect on egg IgY concentration that reflected environmental microbial diversity: females who experienced high diversity deposited more IgY in their eggs, but only if maternal plasma IgY levels were relatively high. We found no effects on lysozyme and ovotransferrin concentrations in albumen. Moreover, we uncovered that variation in egg immune traits could be significantly attributed to differences among females: for IgY concentration in yolk repeatability R = 0.80; for lysozyme concentration in albumen R = 0.27. Furthermore, a partial least squares path model (PLS-PM) linking immune parameters of females and eggs, which included maternal and eggshell microbiota structures and female body condition, recapitulated the treatment-dependent yolk IgY response. The PLS-PM additionally suggested that the microbiota and physical condition of females contributed to shaping maternal effects on egg immune function, and that (non-specific) innate egg immunity was prioritized in the environment with low bacterial diversity. Conclusions The microbial environment of birds can shape maternal effects on egg immune function. Since immunological priming of eggs benefits offspring, we highlight that non-genetic maternal effects on yolk IgY levels based on cues from the parental microbial environment may prove important for offspring to thrive in the microbial environment that they are expected to face. Supplementary Information The online version contains supplementary material available at 10.1186/s42523-022-00195-8.
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Wang Y, Wang J, Kuang Y, Shen W. Packaging with hydrogen gas modified atmosphere can extend chicken egg storage. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:976-983. [PMID: 34302359 DOI: 10.1002/jsfa.11431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/05/2021] [Accepted: 07/24/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Although hydrogen gas (H2 ) has been widely used in industry and gradually used in medicine, it is less applied to agriculture, especially in modified atmosphere packing (MAP). RESULTS During chicken egg storage, H2 MAP not only slowed down or delayed the reduction in antioxidant capacities, but also alleviated the deterioration of egg quality. The extent of micro-cracks in the eggshell was also negatively influenced by H2 , which might result in eggs being less vulnerable to microbes. The earlier results demonstrated that the H2 MAP-extended shelf life of chicken eggs might be caused by the responses of eggshell and re-establishment of redox homeostasis. According to the data collected from different provinces of China, cost-economics analysis further suggested that the increase in the extra cost caused by H2 was trivial compared with the original price of eggs. CONCLUSION Together, H2 MAP can prolong the shelf life of chicken eggs with the prospect of wider application. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Yueqiao Wang
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agriculture University, Nanjing, P.R. China
| | - Junjie Wang
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agriculture University, Nanjing, P.R. China
| | - Yong Kuang
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agriculture University, Nanjing, P.R. China
| | - Wenbiao Shen
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agriculture University, Nanjing, P.R. China
- Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai, P.R. China
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Development of ostrich eggshell and nano-levan-based edible biopolymer composite films: characterization and bioactivity. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-021-04069-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Attard MRG, Bowen J, Corado R, Hall LS, Dorey RA, Portugal SJ. Ecological drivers of eggshell wettability in birds. J R Soc Interface 2021; 18:20210488. [PMID: 34637642 PMCID: PMC8510701 DOI: 10.1098/rsif.2021.0488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 09/13/2021] [Indexed: 01/22/2023] Open
Abstract
Complex and at times extreme environments have pushed many bird species to develop unique eggshell surface properties to protect the embryo from external threats. Because microbes are usually transmitted into eggs by moisture, some species have evolved hydrophobic shell surfaces that resist water absorption, while also regulating heat loss and the exchange of gases. Here, we investigate the relationship between the wettability of eggshells from 441 bird species and their life-history traits. We measured the initial contact angle between sessile water droplets and the shell surface, and how far the droplet spread. Using phylogenetic comparative methods, we show that body mass, annual temperature and eggshell maculation primarily explained variance in water contact angle across eggshells. Species nesting in warm climates were more likely to exhibit highly hydrophobic eggshells than those nesting in cold climates, potentially to reduce microbial colonization. In non-passerines, immaculate eggs were found to have more hydrophobic surfaces than maculate eggshells. Droplets spread more quickly on eggshells incubated in open nests compared to domed nests, likely to decrease heat transfer from the egg. Here, we identify clear adaptations of eggshell wettability across a diverse range of nesting environments, driven by the need to retain heat and prevent microbial adhesion.
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Affiliation(s)
- Marie R. G. Attard
- Department of Biological Sciences, School of Life and Environmental Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
- School of Engineering and Innovation, Open University, Milton Keynes MK7 6AA, UK
| | - James Bowen
- School of Engineering and Innovation, Open University, Milton Keynes MK7 6AA, UK
| | - René Corado
- Western Foundation of Vertebrate Zoology, Camarillo, CA 93012-8506, USA
| | - Linnea S. Hall
- Western Foundation of Vertebrate Zoology, Camarillo, CA 93012-8506, USA
| | - Robert A. Dorey
- Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK
| | - Steven J. Portugal
- Department of Biological Sciences, School of Life and Environmental Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
- The Natural History Museum, Tring, Herts HP23 6AP, UK
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Guinea fowl (Numida meleagris) eggs and free-range housing: a convenient alternative to laying hens' eggs in terms of food safety? Poult Sci 2021; 100:101006. [PMID: 33662664 PMCID: PMC7930637 DOI: 10.1016/j.psj.2021.01.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/21/2020] [Accepted: 01/02/2021] [Indexed: 02/07/2023] Open
Abstract
The aim of this study was to evaluate the impact of the genotype (guinea fowl, native breed Leghorn, and commercial hybrid hens), storage time (0, 14, 28 d) and storage temperature (fresh, 5, 20°C) on eggshell quality traits and microbiological contamination of eggshell, eggshell membranes, and albumen. A total of 150 hens (50 hens per genotype—divided into 2 equal groups because of the results replication) were used. There were 150 eggs (50 per genotype) used for microbial analysis and 600 eggs used for the analysis of eggshell quality. The effects of genotype, storage time, and storage temperature were observed. Moreover, interactions between these factors were calculated. The significant effect of genotype (P = 0.0001) was found in egg weight, in all observed parameters of eggshell quality (proportion, thickness, strength, surface, and index), eggshell contamination of Escherichia coli (EC) and total number of micro-organisms (TNM), penetration of TNM into eggshell membranes (P = 0.0014), and penetration of TNM into albumen (P = 0.0019). Storage time significantly affected egg weight and all parameters of eggshell quality except the eggshell strength and index. It also significantly affected count of Enterococcus (ENT) on eggshell, TNM in eggshell membranes and TNM in albumen. Storage temperature significantly influenced egg weight (P = 0.0001) and all parameters but eggshell thickness and surface. Regarding the microbial contamination, storage temperature significantly affected a count of ENT on shell, TNM in shell membranes, and TNM in albumen. Concerning significant interactions, the interaction among genotype and storage time was found significant (P = 0.0148). Fresh and 28-day-old commercial hybrid eggs were the most contaminated, whereas guinea fowl eggs (fresh and 14 d old) and Leghorn hen eggs (fresh, 14, 28 d old) had the lowest level of contamination by EC. When looking for an alternative to laying hens, guinea fowls should be taken into consideration due to their higher resistance to diseases, ability of adaptation to different environmental conditions, and especially in terms of eggshell quality and therefore egg safety.
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Eeva T, Espín S, Sánchez-Virosta P, Rainio M. Weather effects on breeding parameters of two insectivorous passerines in a polluted area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 729:138913. [PMID: 32375066 DOI: 10.1016/j.scitotenv.2020.138913] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/16/2020] [Accepted: 04/20/2020] [Indexed: 06/11/2023]
Abstract
Direct and indirect effects of environmental pollution affect negatively to birds' breeding performance in both urban and industrial environments, but much less is known on how pollution and natural stress factors work together. In our long-term study (1991-2018), we explored whether industrial pollution and associated habitat changes increase the sensitivity of breeding parameters (hatching and fledging success, nestling growth) to temperature and precipitation in two insectivorous bird species, the great tit (Parus major) and the pied flycatcher (Ficedula hypoleuca). We found that both species are rather weather sensitive in terms of their fledging success, but especially in the F. hypoleuca, the negative effect was strengthened in a polluted environment. For both study species, all the breeding parameters, except growth of F. hypoleuca nestlings, were inferior in the polluted area and negatively affected by cold weather. Independent of pollution, the duration of rainy spells during the nestling period had an overall negative effect on fledging success of F. hypoleuca, and this effect became stronger at cold temperatures. The length of rainy spells was, however, positively associated with nestling wing length in both species, possibly because of better availability of some important food resources for wing growth in more humid conditions. The weather-pollution interactions in our study populations were not overwhelmingly strong, but those found in F. hypoleuca show that such interactions exist, they are species-specific and in our study system most likely associated to pollution-related resource (e.g. food) limitation. Higher sensitivity of F. hypoleuca to low temperatures is likely related to its less well-insulated nests and higher dependence on aerial prey, the availability of which is especially reduced during cold and rainy spells. Our study indicates that anthropogenic stress, such as pollution, has synergistic effects with natural stress factors affecting passerine birds' breeding performance.
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Affiliation(s)
- Tapio Eeva
- Department of Biology, University of Turku, Turku 20014, Finland.
| | - Silvia Espín
- Area of Toxicology, Department of Socio-Sanitary Sciences, University of Murcia, Campus de Espinardo, 30100 Murcia, Spain
| | - Pablo Sánchez-Virosta
- Area of Toxicology, Department of Socio-Sanitary Sciences, University of Murcia, Campus de Espinardo, 30100 Murcia, Spain
| | - Miia Rainio
- Department of Biology, University of Turku, Turku 20014, Finland
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Nwaogu CJ, Cresswell W, Tieleman BI. Geographic variation in baseline innate immune function does not follow variation in aridity along a tropical environmental gradient. Sci Rep 2020; 10:5909. [PMID: 32246110 PMCID: PMC7125124 DOI: 10.1038/s41598-020-62806-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/16/2020] [Indexed: 11/09/2022] Open
Abstract
Geographic variation in aridity determines environmental productivity patterns, including large-scale variability in pathogens, vectors and associated diseases. If disease risk decreases with increasing aridity and is matched by immune defense, we predict a decrease in innate immune function along a gradient of increasing aridity from the cool-wet forest to the hot-dry Sahel, from south to north in Nigeria. We sampled blood and measured five innate immune indices from 286 Common Bulbuls Pycnonotus barbatus between 6 and 13°N. We sampled in the dry season; we resampled the first location (Jos) also as the last sample location to test temporal change in immune function. Immune indices did not decrease with aridity. One immune index, nitric oxide concentration showed a weak quadratic pattern. In Jos, ovotransferrin concentration, haemagglutination and haemolysis titres increased 12 weeks into the dry season, contrary to expectations that immune indices should decrease with increased dryness. In this tropical system, innate immune function does not decrease with increasing aridity but temporal factors within a location may influence immune function more strongly than spatial variation in aridity, suggesting that immune variation does not follow a simple environmental productivity pattern. Consequently, caution should probably be exercised in predicting effects of climate variability on immune function or disease risk.
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Affiliation(s)
- Chima J Nwaogu
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands. .,School of Biology, University of St Andrews, Harold Mitchell Building, St Andrews Fife, KY16 9TH, St. Andrews, UK. .,A.P. Leventis Ornithological Research Institute, Jos, Nigeria. .,Fitzpatrick Institute of African Ornithology, University of Cape Town, 7701, Rondebosch, Cape Town, South Africa.
| | - Will Cresswell
- School of Biology, University of St Andrews, Harold Mitchell Building, St Andrews Fife, KY16 9TH, St. Andrews, UK.,A.P. Leventis Ornithological Research Institute, Jos, Nigeria
| | - B Irene Tieleman
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
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Javůrková VG, Pokorná M, Mikšík I, Tůmová E. Concentration of egg white antimicrobial and immunomodulatory proteins is related to eggshell pigmentation across traditional chicken breeds. Poult Sci 2019; 98:6931-6941. [PMID: 31420680 PMCID: PMC8913977 DOI: 10.3382/ps/pez472] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/30/2019] [Indexed: 12/14/2022] Open
Affiliation(s)
- Veronika Gvoždíková Javůrková
- Department of Animal Science, Czech University of Life Sciences, Kamýcká 129, 165 00 Prague – Suchdol, Czech Republic
- Corresponding author
| | - Monika Pokorná
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44 Prague 2, Czech Republic
| | - Ivan Mikšík
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Eva Tůmová
- Department of Animal Science, Czech University of Life Sciences, Kamýcká 129, 165 00 Prague – Suchdol, Czech Republic
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Chen X, Li X, He Z, Hou Z, Xu G, Yang N, Zheng J. Comparative study of eggshell antibacterial effectivity in precocial and altricial birds using Escherichia coli. PLoS One 2019; 14:e0220054. [PMID: 31339918 PMCID: PMC6655735 DOI: 10.1371/journal.pone.0220054] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 07/08/2019] [Indexed: 02/05/2023] Open
Abstract
In this study, we compared the antibacterial effectivity of the eggs of six precocial and four altricial bird species using Escherichia coli, based on their eggshell traits. The ultrastructure of eggshell was observed using a scanning electron microscope (SEM). According to SEM results, eggs from precocial birds (chicken, turkey, quail, duck, ostrich, and goose) had cuticle on the eggshells, while eggs from altricial birds (pigeon, budgerigar, munia, and canary) did not. The environment/selection pressure may induce the divergent evolution process in eggs of precocial and altricial birds. The E. coli experiment results showed that chicken, turkey, quail, duck, and goose eggs, with a high cuticle opacity, exhibited a much lower E. coli penetration rate. In contrast, the eggs with poor (ostrich) or without (pigeon, budgerigar, munia, and canary) cuticle exhibited a higher penetration rate. It is suggested that cuticle is a main barrier against bacterial penetration in precocial birds’ eggs. Turkey and quail eggs showed the lowest E. coli contamination rate (3.33% and 2.22%, respectively), probably because of the tightly connected nanosphere structure on their cuticle. As for altricial birds’ eggs, the eggs of budgerigar, munia, and canary with small pore diameter (0.57 to 1.22 μm) had a lower E. coli penetration rate than pigeon eggs (45.56%, 66.67%, 50%, and 97.78%, respectively, P < 0.05), indicating that pore diameter played a significant role in defending against bacterial trans-shell invasion. We found that eggshell thickness and pore area decreased with egg size. The cuticle quality had no relationship with egg size, but was closely related to the bird species. The E. coli penetration rate of altricial birds’ eggs was significantly higher than that of precocial birds’ eggs, mainly because the pores are exposed on the eggshell surface and cuticle protection is absent. This study provides detailed information on the eggshell cuticle, which gives insight into the cuticle evolution process that occurred in precocial and altricial bird species. Moreover, the results of E. coli penetration may help understanding the antibacterial behavior in birds.
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Affiliation(s)
- Xia Chen
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Xingzheng Li
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zhaoxiang He
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zhuocheng Hou
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Guiyun Xu
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Ning Yang
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Jiangxia Zheng
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
- * E-mail:
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12
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Svobodová J, Šmídová L, Javůrková VG. Different incubation patterns affect selective antimicrobial properties of the egg interior: experimental evidence from eggs of precocial and altricial birds. ACTA ACUST UNITED AC 2019; 222:jeb.201442. [PMID: 30814292 DOI: 10.1242/jeb.201442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 02/22/2019] [Indexed: 12/14/2022]
Abstract
Avian eggs contend with omnipresent microorganisms entering the egg interior, where they affect embryo viability and hatchling phenotype. The incubation behaviour and deposition of egg white antimicrobial proteins (AMPs) vary highly across the avian altricial-precocial spectrum. Experimental evidence of how these alterations in avian reproductive strategies affect the antimicrobial properties of the precocial and altricial egg interior is lacking, however. Here, we tested the egg white antimicrobial activity in eggs of two representative model species, from each end of the avian altricial-precocial spectrum, against potentially pathogenic and beneficial probiotic microorganisms. Eggs were experimentally treated to mimic un-incubated eggs in the nest, partial incubation during the egg-laying period, the onset of full incubation and the increased deposition of two main egg white AMPs, lysozyme and ovotransferrin. We moreover assessed to what extent egg antimicrobial components, egg white pH and AMP concentrations varied as a result of different incubation patterns. Fully incubated precocial and altricial eggs decreased their antimicrobial activity against a potentially pathogenic microorganism, whereas partial incubation significantly enhanced the persistence of a beneficial probiotic microorganism in precocial eggs. These effects were most probably conditioned by temperature-dependent alterations in egg white pH and AMP concentrations. While lysozyme concentration and pH decreased in fully incubated precocial but not altricial eggs, egg white ovotransferrin increased along with the intensity of incubation in both precocial and altricial eggs. This study is the first to experimentally demonstrate that different incubation patterns may have selective antimicrobial potential mediated by species-specific effects on antimicrobial components in the egg white.
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Affiliation(s)
- Jana Svobodová
- Czech University of Life Sciences, Faculty of Environmental Sciences, Department of Ecology, Kamýcká 1176, 165 21 Prague 6, Czech Republic
| | - Lucie Šmídová
- Charles University, Faculty of Science, Department of Zoology, Viničná 7, 128 44 Prague 2, Czech Republic
| | - Veronika Gvoždíková Javůrková
- Czech University of Life Sciences, Faculty of Agrobiology, Food and Natural Resources, Department of Animal Science, Kamýcká 957, 165 21 Prague 6, Czech Republic
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Peralta-Sánchez JM, Martín-Platero AM, Wegener-Parfrey L, Martínez-Bueno M, Rodríguez-Ruano S, Navas-Molina JA, Vázquez-Baeza Y, Martín-Gálvez D, Martín-Vivaldi M, Ibáñez-Álamo JD, Knight R, Soler JJ. Bacterial density rather than diversity correlates with hatching success across different avian species. FEMS Microbiol Ecol 2019; 94:4847879. [PMID: 29438507 DOI: 10.1093/femsec/fiy022] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 02/07/2018] [Indexed: 01/09/2023] Open
Abstract
Bacterial communities within avian nests are considered an important determinant of egg viability, potentially selecting for traits that confer embryos with protection against trans-shell infection. A high bacterial density on the eggshell increases hatching failure, whether this effect could be due to changes in bacterial community or just a general increase in bacterial density. We explored this idea using intra- and interspecific comparisons of the relationship between hatching success and eggshell bacteria characterized by culture and molecular techniques (fingerprinting and high-throughput sequencing). We collected information for 152 nests belonging to 17 bird species. Hatching failures occurred more frequently in nests with higher density of aerobic mesophilic bacteria on their eggshells. Bacterial community was also related to hatching success, but only when minority bacterial operational taxonomic units were considered. These findings support the hypothesis that bacterial density is a selective agent of embryo viability, and hence a proxy of hatching failure only within species. Although different avian species hold different bacterial densities or assemblages on their eggs, the association between bacteria and hatching success was similar for different species. This result suggests that interspecific differences in antibacterial defenses are responsible for keeping the hatching success at similar levels in different species.
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Affiliation(s)
- Juan Manuel Peralta-Sánchez
- Departamento de Microbiología, Universidad de Granada, Calle Fuentenueva, s/n, E-18071 Granada, Spain.,Department of Integrative Ecology, Estación Biológica de Doñana, C.S.I.C. Avda. Américo Vespucio s/n, E-41092 Seville, Spain
| | | | | | - Manuel Martínez-Bueno
- Departamento de Microbiología, Universidad de Granada, Calle Fuentenueva, s/n, E-18071 Granada, Spain
| | - Sonia Rodríguez-Ruano
- Departamento de Microbiología, Universidad de Granada, Calle Fuentenueva, s/n, E-18071 Granada, Spain.,Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic
| | - José Antonio Navas-Molina
- Department of Computer Science & Engineering University of California San Diego, La Jolla, CA 92093, USA
| | - Yoshiki Vázquez-Baeza
- Department of Computer Science & Engineering University of California San Diego, La Jolla, CA 92093, USA
| | - David Martín-Gálvez
- European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, Cambridge, CB10 1SD, UK
| | - Manuel Martín-Vivaldi
- Departamento de Zoología, Universidad de Granada, Campus de Fuentenueva, s/n, E-18071 Granada, Spain
| | - Juan Diego Ibáñez-Álamo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen. 9700 CC Groningen, The Netherlands
| | - Rob Knight
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA
| | - Juan José Soler
- Departamento de Ecología Funcional y Evolutiva. Estación Experimental de Zonas Áridas, C.S.I.C., E-04120 Almería, Spain
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14
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Valcu CM, Scheltema RA, Schweiggert RM, Valcu M, Teltscher K, Walther DM, Carle R, Kempenaers B. Life history shapes variation in egg composition in the blue tit Cyanistes caeruleus. Commun Biol 2019; 2:6. [PMID: 30740542 PMCID: PMC6320336 DOI: 10.1038/s42003-018-0247-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 12/02/2018] [Indexed: 12/26/2022] Open
Abstract
Maternal investment directly shapes early developmental conditions and therefore has long-term fitness consequences for the offspring. In oviparous species prenatal maternal investment is fixed at the time of laying. To ensure the best survival chances for most of their offspring, females must equip their eggs with the resources required to perform well under various circumstances, yet the actual mechanisms remain unknown. Here we describe the blue tit egg albumen and yolk proteomes and evaluate their potential to mediate maternal effects. We show that variation in egg composition (proteins, lipids, carotenoids) primarily depends on laying order and female age. Egg proteomic profiles are mainly driven by laying order, and investment in the egg proteome is functionally biased among eggs. Our results suggest that maternal effects on egg composition result from both passive and active (partly compensatory) mechanisms, and that variation in egg composition creates diverse biochemical environments for embryonic development.
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Affiliation(s)
- Cristina-Maria Valcu
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
| | - Richard A. Scheltema
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Ralf M. Schweiggert
- Plant Foodstuff Technology and Analysis, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany
| | - Mihai Valcu
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
| | - Kim Teltscher
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
| | - Dirk M. Walther
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Reinhold Carle
- Plant Foodstuff Technology and Analysis, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany
- Biological Science Department, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Bart Kempenaers
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
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15
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Fassbinder-Orth CA, Igl LD, Hahn DC, Watts KM, Wilcoxen TE, Ramos-Álvarez KR. Do Life History Traits Influence Patterns of Maternal Immune Elements in New World Blackbirds (Icteridae)? Integr Org Biol 2018. [DOI: 10.1093/iob/oby011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Avian immunology developed originally by investigating domesticated poultry species (Galliformes), but in recent decades eco-immunological studies of wild bird species have revealed that avian immune systems are more diverse than initially assumed. This study compares six immunological elements in eggs of six species within the same family, the New World blackbirds (Icteridae),whose members differ most notably in two life history parameters, brood parasitism and body size. We measured the maternal immune investment of passive immune components in both yolk and albumen: lysozyme, ovotransferrin, and immunoglobulins (Igs), and LPS-specific Igs. We predicted that brood parasites would have higher levels of immune activity for both innate and adaptive immunity compared with non-brood parasites, and that increased body size could increase microbial exposure of larger animals, resulting in an increase in some adaptive immune responses, such as LPS-specific Igs. We found that brood parasites had significantly higher levels of Igs and lysozyme levels in albumen, but significantly lower levels of Igs in yolk compared with non-brood parasites. Igs in yolk scaled according to body size, with the smallest organisms (the brood parasites) having the lowest levels, and the largest organism (common grackle) having the highest. Our results confirm the findings of other studies of comparative immunity among species in a single taxon that (1) similarities in immune investment cannot be assumed among closely related species and (2) single measures of immune defense cannot be assumed to be indicators of a species’ overall immune strategy, as life history traits can differentially affect immune responses.
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Affiliation(s)
- C A Fassbinder-Orth
- Department of Biology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - L D Igl
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, 8711 37th Street Southeast, Jamestown, ND 58401, USA
| | - D C Hahn
- U.S. Geological Survey, Patuxent Wildlife Research Center, 12110 Beech Forest Road Laurel, MD 20708, USA
| | - K M Watts
- Department of Biology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
- Novozymes Blair, Inc., 600 South 1st Street, Blair, NE 68008, USA
| | - T E Wilcoxen
- Department of Biology, Millikin University, 1184 West Main Street, Decatur, IL 62522, USA
| | - K R Ramos-Álvarez
- Departamento de Recursos Naturales y Ambientales de Puerto Rico, Laboratorio de Investigaciones Pesqueras, P.O. Box 3665, Marina Station, Mayagüez, PR 00681, Puerto Rico
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16
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Brusch GA, Heulin B, DeNardo DF. Dehydration during egg production alters egg composition and yolk immune function. Comp Biochem Physiol A Mol Integr Physiol 2018; 227:68-74. [PMID: 30300746 DOI: 10.1016/j.cbpa.2018.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 12/31/2022]
Abstract
Parent-offspring conflicts occur when resources are limited for allocation, and, historically, energy has been the primary currency of focus when examining these trade-offs. Water is a fundamental resource that has received far less consideration for parent-offspring conflicts. Previous research suggests that, when water is limited, reproductive females are compromised in favor of developing embryos. However, these studies limited their assessments to standard metrics such as clutch size and mass. We tested the hypothesis that the mother-offspring conflict over limited water resources leads to finer scale morphological and physiological impacts on the eggs in Children's pythons (Antaresia childreni). We predicted that water deprivation during gravidity alters female investment into her eggs, impacting egg water content and shell development. Additionally, we predicted that the yolk in these dehydrated eggs would have enhanced immune performance metrics, as has been documented in dehydrated adults. We found that eggs from water-deprived females were dehydrated as indicated by reduced percent water and greater yolk osmolality compared to eggs from females that received ad libitum water. We also found that eggs from dehydrated mothers had thinner shells and higher water loss rates. The impacts were not entirely negative as dehydrated eggs had higher antimicrobial capabilities. Also, thinner and more permeability eggshells might allow for elevated rates of rehydration from nest substrate. Overall, by examining an array of egg traits, we demonstrated that dehydration of gravid females impacts the eggs, not just the females as previously reported. As a result, the mother-offspring conflicts are indeed two-sided.
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Affiliation(s)
- George A Brusch
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85281, USA.
| | - Benoit Heulin
- Paimpont Biological Station, CNRS UMR6553, University of Rennes 1, 35380 Paimpont, France
| | - Dale F DeNardo
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85281, USA
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17
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Rubio E, Sanllorente O, Tieleman BI, Ibáñez-Álamo JD. Fecal sacs do not increase nest predation in a ground nester. JOURNAL OF ORNITHOLOGY 2018; 159:985-990. [PMID: 30956930 PMCID: PMC6417374 DOI: 10.1007/s10336-018-1566-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/24/2018] [Accepted: 05/14/2018] [Indexed: 06/09/2023]
Abstract
Most altricial birds remove their nestlings' feces from the nest, but the evolutionary forces driving this behavior are poorly understood. A possible adaptive explanation for this could be that birds avoid the attraction of nest predators to their nests due to the visual or olfactory cues produced by feces (nest predation hypothesis). This hypothesis has received contrasting support indicating that additional experimental studies are needed, particularly with respect to the visual component of fecal sacs. To test this hypothesis, we conducted an experiment manipulating the presence of fecal sacs on inactive Woodlark (Lullula arborea) nests. This ground nester has highly cryptic nests that are mainly depredated by visually oriented nest predators (i.e., corvids) in our study population, making it an excellent system to test for the nest predation hypothesis. Our results showed that the presence of fecal sacs in the nest does not seem to be an important factor explaining nest predation. Interestingly, the effect of nest concealment, the most important factor explaining nest predation in Woodlark nests, depended on whether the nest was depredated the previous year or not, supporting the importance of using different nesting sites between years. Our findings indicate that this important nest sanitation behavior is not likely motivated by nest predation and highlight the need to explore alternative selective pressures in this context.
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Affiliation(s)
- Enrique Rubio
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands
| | - Olivia Sanllorente
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands
| | - B. Irene Tieleman
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands
| | - Juan Diego Ibáñez-Álamo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands
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18
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Krkavcová E, Kreisinger J, Hyánková L, Hyršl P, Javůrková V. The hidden function of egg white antimicrobials: egg weight-dependent effects of avidin on avian embryo survival and hatchling phenotype. Biol Open 2018. [PMID: 29540428 PMCID: PMC5936061 DOI: 10.1242/bio.031518] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Avidin is a key egg white antimicrobial protein with strong binding capacity for biotin, an essential growth and immune cell precursor. As such, it is assumed to have a pronounced, though still poorly explored, effect on hatchling phenotype. We tested the effect of experimentally increased egg white avidin concentration (AVIDIN+) on hatching success, chick morphology, post-hatching growth performance and innate immune function in a model bird, Japanese quail (Coturnix japonica). Probability of embryo survival in the late embryonic phase increased with increasing egg weight in control eggs, but not in AVIDIN+ eggs. Chicks hatching from lighter AVIDIN+ eggs had a shorter tarsus than chicks hatching from heavier AVIDIN+ eggs. This suggests that an increase in egg white avidin favours embryo survival in lighter eggs during late embryogenesis, but at the expense of reduced structural body size. Plasma complement activity in 6-day-old AVIDIN+ chicks decreased with increasing body mass and tarsus length; the opposite was observed in control chicks, implying that the later post-hatching innate immune function of larger chicks was compromised by an increase in egg white avidin concentration. Here, we document an important role of egg white antimicrobials in maintenance of embryo viability, avian hatchling morphology and immune phenotype. Summary: This is the first experimental study to evaluate the effects of increased concentration of egg white antimicrobial protein avidin on embryo viability, hatchling morphology and immune phenotype in birds.
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Affiliation(s)
- Eva Krkavcová
- Department of Zoology, Charles University, Viničná 7, 128 44, Prague, Czech Republic
| | - Jakub Kreisinger
- Department of Zoology, Charles University, Viničná 7, 128 44, Prague, Czech Republic
| | - Ludmila Hyánková
- Department of Genetics and Breeding of Farm Animals, VÚŽv.v.i., Přátelství 815, 104 00, Prague-Uhříněves, Czech Republic
| | - Pavel Hyršl
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Veronika Javůrková
- The Czech Academy of Sciences, Institute of Vertebrate Biology, Květná 8, 603 65 Brno, Czech Republic .,Department of Animal Husbandry, Czech University of Life Sciences, Kamýcká 129, 165 00 Prague - Suchdol, Czech Republic
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19
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Martínez-García Á, Martín-Vivaldi M, Rodríguez-Ruano SM, Peralta-Sánchez JM, Valdivia E, Soler JJ. Nest Bacterial Environment Affects Microbiome of Hoopoe Eggshells, but Not That of the Uropygial Secretion. PLoS One 2016; 11:e0158158. [PMID: 27409772 PMCID: PMC4943718 DOI: 10.1371/journal.pone.0158158] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/10/2016] [Indexed: 11/18/2022] Open
Abstract
The study of associations between symbiotic bacterial communities of hosts and those of surrounding environments would help to understand how bacterial assemblages are acquired, and how they are transmitted from one to another location (i.e. symbiotic bacteria acquisition by hosts). Hoopoes (Upupa epops) smear their eggshells with uropygial secretion (oily secretion produced in their uropygial gland) that harbors antibiotic producing bacteria. Trying to elucidate a possible role of nest material and cloaca microbiota in determining the bacterial community of the uropygial gland and the eggshells of hoopoes, we characterized bacterial communities of nest material, cloaca, uropygial gland and eggshells by the ARISA fingerprinting. Further, by adding material with scarce bacteria and antimicrobial properties, we manipulated the bacterial community of nest material and thus tested experimentally its effects on the microbiomes of the uropygial secretion and of the eggshells. The experiment did not influence the microbiome of the uropygial secretion of females, but affected the community established on eggshells. This is the first experimental evidence indicating that nest material influences the bacterial community of the eggshells and, therefore, probability of embryo infection. Some of the bacterial strains detected in the secretion were also in the bacterial communities of the nest material and of cloaca, but their occurrence within nests was not associated, which suggests that bacterial environments of nest material and cloaca are not sources of symbiotic bacteria for the gland. These results do not support a role of nest environments of hoopoes as reservoirs of symbiotic bacteria. We discuss possible scenarios explaining bacterial acquisition by hoopoes that should be further explored.
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Affiliation(s)
| | | | | | | | - Eva Valdivia
- Departamento de Microbiología Universidad de Granada, E-18071 Granada, Spain
| | - Juan J. Soler
- Estación Experimental de Zonas Áridas (CSIC) E-04120 Almería, Spain
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20
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Abstract
Selective pressures imposed by pathogenic microorganisms to embryos have selected in hosts for a battery of antimicrobial lines of defenses that includes physical and chemical barriers. Due to the antimicrobial properties of volatile compounds of green plants and of chemicals of feather degrading bacteria, the use of aromatic plants and feathers for nest building has been suggested as one of these barriers. However, experimental evidence suggesting such effects is scarce in the literature. During two consecutive years, we explored experimentally the effects of these nest materials on loads of different groups of bacteria (mesophilic bacteria, Enterobacteriaceae, Staphylococcus and Enterococcus) of eggshells in nests of spotless starlings (Sturnus unicolor) at the beginning and at the end of the incubation period. This was also explored in artificial nests without incubation activity. We also experimentally increased bacterial density of eggs in natural and artificial nests and explored the effects of nest lining treatments on eggshell bacterial load. Support for the hypothetical antimicrobial function of nest materials was mainly detected for the year and location with larger average values of eggshell bacterial density. The beneficial effects of feathers and plants were more easily detected in artificial nests with no incubation activity, suggesting an active role of incubation against bacterial colonization of eggshells. Pigmented and unpigmented feathers reduced eggshell bacterial load in starling nests and artificial nest boxes. Results from artificial nests allowed us to discuss and discard alternative scenarios explaining the detected association, particularly those related to the possible sexual role of feathers and aromatic plants in starling nests. All these results considered together confirm the antimicrobial functionality mainly of feathers but also of plants used as nest materials, and highlight the importance of temporally and geographically environmental variation associated with risk of bacterial proliferation determining the strength of such effects. Because of costs associated to nest building, birds should adjust nest building effort to expected bacterial environments during incubation, a prediction that should be further explored.
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21
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Grizard S, Versteegh MA, Ndithia HK, Salles JF, Tieleman BI. Shifts in bacterial communities of eggshells and antimicrobial activities in eggs during incubation in a ground-nesting passerine. PLoS One 2015; 10:e0121716. [PMID: 25880684 PMCID: PMC4400097 DOI: 10.1371/journal.pone.0121716] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 02/14/2015] [Indexed: 01/26/2023] Open
Abstract
Microbial invasion of egg contents is a cause of embryonic death. To counter infection risks, the embryo is protected physically by the eggshell and chemically by antimicrobial proteins. If microbial pressure drives embryo mortality, then females may have evolved, through natural selection, to adapt their immune investment into eggs. Although frequently hypothesized, this match between immune allocation and microorganisms has not been explored yet. To examine if correlations between microbes on eggs and immunity in eggs exist, we collected eggs from red-capped larks (Calandrella cinerea) and simultaneously examined their bacterial communities and antimicrobial components—pH, lysozyme and ovotransferrin—during natural incubation. Using molecular techniques, we find that bacterial communities are highly dynamic: bacterial abundance increases from the onset to late incubation, Shannon’s α-diversity index increases during early incubation stages, and β-diversity analysis shows that communities from 1 day-old clutches are phylogenetically more similar to each other than the older ones. Regarding the antimicrobials, we notice a decrease of pH and lysozyme concentration, while ovotransferrin concentration increases during incubation. Interestingly, we show that two eggs of the same clutch share equivalent immune protection, independent of clutch age. Lastly, our results provide limited evidence of significant correlation between antimicrobial compounds and bacterial communities. Our study examined simultaneously, for the first time in a wild bird, the dynamics of bacterial communities present on eggshells and of albumen-associated antimicrobial components during incubation and investigated their relationship. However, the link between microorganisms and immunity of eggs remains to be elucidated further. Identifying invading microbes and their roles in embryo mortality, as well as understanding the role of the eggshell microbiome, might be key to better understand avian strategies of immune maternal investment.
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Affiliation(s)
- Stéphanie Grizard
- Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
- * E-mail:
| | - Maaike A. Versteegh
- Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Henry K. Ndithia
- Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
- Department of Zoology, Ornithology section, National Museums of Kenya, Nairobi, Kenya
| | - Joana F. Salles
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - B. Irene Tieleman
- Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
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22
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Environmental proxies of antigen exposure explain variation in immune investment better than indices of pace of life. Oecologia 2014; 177:281-90. [DOI: 10.1007/s00442-014-3136-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 10/24/2014] [Indexed: 10/24/2022]
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