1
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Carbillet J, Saks L, Sepp T. Salivary corticosterone reflects plasmatic levels in a wild seabird. Gen Comp Endocrinol 2024; 345:114390. [PMID: 37844650 DOI: 10.1016/j.ygcen.2023.114390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/11/2023] [Accepted: 10/11/2023] [Indexed: 10/18/2023]
Abstract
Wild animals have been increasingly exposed to a wide range of stressors, mainly due to the intensification of human activities and habitat modifications. Consequently, new tools in order to assess the physiological and health status of wild animals have been developed. In particular, glucocorticoids have received a special attention. Primarily metabolic hormones, they are also used to evaluate the stress level of organisms. While historically measured in blood samples, new less-invasive methods have been recently developed to measure glucocorticoids in matrices such as faeces, hairs/feathers, or saliva. To date, measurements in saliva are still in their infancy despite the numerous advantages of the matrix: non-invasive, reflects the biologically active portion of glucocorticoids, allows to measure both baseline and stress-induced levels. In addition, most studies using saliva have been performed on domestic and captive animals, and recent development in wild animals have focused on mammals. Here, we show, for the first time, that saliva could also be reliably used in free-ranging birds, as glucocorticoid levels in saliva strongly correlated with plasma levels. This promising result opens new avenues for a non-invasive sampling method to assess health status of wild birds in conservation biology and ecology.
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Affiliation(s)
- Jeffrey Carbillet
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu 51014, Estonia.
| | - Lauri Saks
- Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618 Tallinn, Harju County, Estonia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu 51014, Estonia
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2
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Sepp T, Baines C, Kreitsberg R, Scharsack JP, Nogueira P, Lang T, Fort J, Sild E, Clarke JT, Tuvikene A, Meitern R. Differences on the level of hepatic transcriptome between two flatfish species in response to liver cancer and environmental pollution levels. Comp Biochem Physiol C Toxicol Pharmacol 2024; 275:109781. [PMID: 37923151 DOI: 10.1016/j.cbpc.2023.109781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/20/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023]
Abstract
Environmental factors can cause cancer in both wild animals and humans. In ecological settings, genetic variation and natural selection can sometimes produce resilience to the negative impacts of environmental change. An increase in oncogenic substances in natural habitats has therefore, unintentionally, created opportunities for using polluted habitats to study cancer defence mechanisms. The Baltic and North Sea are among the most contaminated marine areas, with a long history of pollution. Two flatfish species (flounder, Platichthys flesus and dab, Limanda limanda) are used as ecotoxicological indicator species due to pollution-induced liver cancer. Cancer is more prevalent in dab, suggesting species-specific differences in vulnerability and/or defence mechanisms. We conducted gene expression analyses for 30 flatfishes. We characterize between- and within-species patterns in potential cancer-related mechanisms. By comparing cancerous and healthy fishes, and non-cancerous fishes from clean and polluted sites, we suggest also genes and related physiological mechanisms that could contribute to a higher resistance to pollution-induced cancer in flounders. We discovered changes in transcriptome related to elevated pollutant metabolism, alongside greater tumour suppression mechanisms in the liver tissue of flounders compared to dabs. This suggests either hormetic upregulation of tumour suppression or a stronger natural selection pressure for higher cancer resistance for flounders in polluted environment. Based on gene expression patterns seen in cancerous and healthy fish, for liver cancer to develop in flounders, genetic defence mechanisms need to be suppressed, while in dabs, analogous process is weak or absent. We conclude that wild species could offer novel insights and ideas for understanding the nature and evolution of natural cancer defence mechanisms.
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Affiliation(s)
- Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia. https://twitter.com/@TuulSeppLab
| | - Ciara Baines
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia; Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618 Tallinn, Harju County, Estonia
| | - Randel Kreitsberg
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
| | - Jörn Peter Scharsack
- Thünen Institute of Fisheries Ecology, Herwigstraße 31, 27572 Bremerhaven, Germany
| | - Pedro Nogueira
- Thünen Institute of Fisheries Ecology, Herwigstraße 31, 27572 Bremerhaven, Germany
| | - Thomas Lang
- Thünen Institute of Fisheries Ecology, Herwigstraße 31, 27572 Bremerhaven, Germany
| | - Jérôme Fort
- Littoral, Environnement et Sociétés (LIENSs), UMR7266 CNRS - La Rochelle University, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Elin Sild
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
| | - John T Clarke
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia; GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 Munich, Germany; Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 Munich, Germany; Department of Ecology and Biogeography, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland
| | - Arvo Tuvikene
- Estonian University of Life Sciences, Friedrich Reinhold Kreutzwaldi 1a, 51014 Tartu, Estonia
| | - Richard Meitern
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
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3
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Kreitsberg R, Nääb L, Meitern R, Carbillet J, Fort J, Giraudeau M, Sepp T. The effect of environmental pollution on gene expression of seabirds: A review. Mar Environ Res 2023; 189:106067. [PMID: 37393763 DOI: 10.1016/j.marenvres.2023.106067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/04/2023]
Abstract
One of the biggest challenges for ecotoxicologists is to detect harmful effects of contaminants on individual organisms before they have caused significant harm to natural populations. One possible approach for discovering sub-lethal, negative health effects of pollutants is to study gene expression, to identify metabolic pathways and physiological processes affected by contaminants. Seabirds are essential components of ecosystems but highly threatened by environmental changes. Being at the top of the food chain and exhibiting a slow pace of life, they are highly exposed to contaminants and to their ultimate impacts on populations. Here we provide an overview of the currently available seabird-related gene expression studies in the context of environmental pollution. We show that studies conducted, so far, mainly focus on a small selection of xenobiotic metabolism genes, often using lethal sampling protocols, while the greater promise of gene expression studies for wild species may lie in non-invasive procedures focusing on a wider range of physiological processes. However, as whole genome approaches might still be too expensive for large-scale assessments, we also bring out the most promising candidate biomarker genes for future studies. Based on the biased geographical representativeness of the current literature, we suggest expanding studies to temperate and tropical latitudes and urban environments. Also, as links with fitness traits are very rare in the current literature, but would be highly relevant for regulatory purposes, we point to an urgent need for establishing long-term monitoring programs in seabirds that would link pollutant exposure and gene expression to fitness traits.
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Affiliation(s)
- Randel Kreitsberg
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51003, Tartu, Estonia.
| | - Lisanne Nääb
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51003, Tartu, Estonia
| | - Richard Meitern
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51003, Tartu, Estonia
| | - Jeffrey Carbillet
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51003, Tartu, Estonia
| | - Jérôme Fort
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266, CNRS - La Rochelle Université, 2 Rue Olympe de Gouges, 17000, La Rochelle, France
| | - Mathieu Giraudeau
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266, CNRS - La Rochelle Université, 2 Rue Olympe de Gouges, 17000, La Rochelle, France
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51003, Tartu, Estonia
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4
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Baines C, Meitern R, Kreitsberg R, Fort J, Scharsack JP, Nogueira P, Giraudeau M, Sepp T. Correlations between oxidative DNA damage and formation of hepatic tumours in two flatfish species from contaminated environments. Biol Lett 2023; 19:20220583. [PMID: 37254521 DOI: 10.1098/rsbl.2022.0583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023] Open
Abstract
Many species in aquatic environments face increased exposure to oncogenic pollution due to anthropogenic environmental change which can lead to higher cancer prevalence. The mechanistic relationship connecting environmental pollution and cancer is multi-factorial and poorly understood, and the specific mechanisms are so far still uncharacterized. One potential mediator between pollutant exposure and cancer is oxidative damage to DNA. We conducted a study in the field with two flatfish species, European flounder (Platichthys flesus L.) and common dab (Limanda limanda L.) with overlapping distribution and similar ecological niche, to investigate if the link between oncogenic pollutants and cancer described in ecotoxicological literature could be mediated by oxidative DNA damage. This was not the case for flounders as neither polycyclic aromatic hydrocarbon (PAH) bile metabolites nor metallic trace element concentrations were related to oxidative DNA damage measurements. However, dabs with higher PAH concentrations did exhibit increased oxidative damage. High oxidative DNA damage also did not predict neoplasm occurrence, rather, healthy individuals tended to have higher oxidative damage measurements compared to fishes with pre-neoplastic tumours. Our analyses showed that flounders had lower concentrations of PAH bile metabolites, suggesting that compared to dab this species is less exposed or better at eliminating these contaminants.
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Affiliation(s)
- Ciara Baines
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
- Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618 Tallinn, Harju County, Estonia
| | - Richard Meitern
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
| | - Randel Kreitsberg
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
| | - Jérôme Fort
- Littoral, Environnement et Sociétés (LIENSs), UMR7266 CNRS - La Rochelle Université, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Jörn Peter Scharsack
- Thünen Institute of Fisheries Ecology, Herwigstraße 31, 27572 Bremerhaven, Germany
| | - Pedro Nogueira
- Thünen Institute of Fisheries Ecology, Herwigstraße 31, 27572 Bremerhaven, Germany
| | - Mathieu Giraudeau
- Littoral, Environnement et Sociétés (LIENSs), UMR7266 CNRS - La Rochelle Université, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
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5
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Sepp T, Giraudeau M. Wild animals as an underused treasure trove for studying the genetics of cancer. Bioessays 2023; 45:e2200188. [PMID: 36404107 DOI: 10.1002/bies.202200188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/22/2022]
Abstract
Recent years have seen an emergence of the field of comparative cancer genomics. However, the advancements in this field are held back by the hesitation to use knowledge obtained from human studies to study cancer in other animals, and vice versa. Since cancer is an ancient disease that arose with multicellularity, oncogenes and tumour-suppressor genes are amongst the oldest gene classes, shared by most animal species. Acknowledging that other animals are, in terms of cancer genetics, ecology, and evolution, rather similar to humans, creates huge potential for advancing the fields of human and animal oncology, but also biodiversity conservation. Also see the video abstract here: https://youtu.be/UFqyMx5HETY.
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Affiliation(s)
- Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Mathieu Giraudeau
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, La Rochelle, France
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Sepp T, Meitern R, Heidinger B, Noreikiene K, Rattiste K, Hõrak P, Saks L, Kittilson J, Urvik J, Giraudeau M. Parental age does not influence offspring telomeres during early life in common gulls (Larus canus). Mol Ecol 2022; 31:6197-6207. [PMID: 33772917 DOI: 10.1111/mec.15905] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 02/27/2021] [Accepted: 03/22/2021] [Indexed: 01/31/2023]
Abstract
Parental age can affect offspring telomere length through heritable and epigenetic-like effects, but at what stage during development these effects are established is not well known. To address this, we conducted a cross-fostering experiment in common gulls (Larus canus) that enabled us distinguish between pre- and post-natal parental age effects on offspring telomere length. Whole clutches were exchanged after clutch completion within and between parental age classes (young and old) and blood samples were collected from chicks at hatching and during the fastest growth phase (11 days later) to measure telomeres. Neither the ages of the natal nor the foster parents predicted the telomere length or the change in telomere lengths of their chicks. Telomere length (TL) was repeatable within chicks, but increased across development (repeatability = 0.55, intraclass correlation coefficient within sampling events 0.934). Telomere length and the change in telomere length were not predicted by post-natal growth rate. Taken together, these findings suggest that in common gulls, telomere length during early life is not influenced by parental age or growth rate, which may indicate that protective mechanisms buffer telomeres from external conditions during development in this relatively long-lived species.
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Affiliation(s)
- Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Richard Meitern
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Britt Heidinger
- Biological Sciences Department, North Dakota State University, Fargo, ND, USA
| | - Kristina Noreikiene
- Institute of Veterinary Medicine, Estonian University of Life Sciences, Tartu, Estonia
| | - Kalev Rattiste
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Peeter Hõrak
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Lauri Saks
- Estonian Marine Institute, University of Tartu, Tartu, Estonia
| | - Jeffrey Kittilson
- Biological Sciences Department, North Dakota State University, Fargo, ND, USA
| | - Janek Urvik
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia.,Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Mathieu Giraudeau
- CREEC, Montpellier Cedex 5, France.,MIVEGEC, UMR IRD/CNRS/UM 5290, Montpellier Cedex 5, France
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7
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Baines C, Meitern R, Kreitsberg R, Sepp T. Comparative study of the evolution of cancer gene duplications across fish. Evol Appl 2022; 15:1834-1845. [PMID: 36426117 PMCID: PMC9679246 DOI: 10.1111/eva.13481] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 09/05/2022] [Accepted: 09/07/2022] [Indexed: 12/04/2022] Open
Abstract
Comparative studies of cancer‐related genes not only provide novel information about their evolution and function but also an understanding of cancer as a driving force in biological systems and species’ life histories. So far, these studies have focused on mammals. Here, we provide the first comparative study of cancer‐related gene copy number variation in fish. Fishes are a paraphyletic group whose last common ancestor is also an ancestor of the tetrapods, and accordingly, their tumour suppression mechanisms should include most of the mammalian mechanisms and also reveal novel (but potentially phylogenetically older) previously undetected mechanisms. We have matched the sequenced genomes of 65 fish species from the Ensemble database with the cancer gene information from the COSMIC database. By calculating the number of gene copies across species using the Ensembl CAFE data (providing species trees for gene copy number counts), we used a less resource‐demanding method for homolog identification. Our analysis demonstrates a masked relationship between cancer‐related gene copy number variation (CNV) and maximum lifespan in fish species, suggesting that a higher number of copies of tumour suppressor genes lengthens and the number of copies of oncogenes shortens lifespan. Based on the positive correlation between the number of copies of tumour suppressors and oncogenes, we show which species have more tumour suppressors in relation to oncogenes. It could be suggested that these species have stronger genetic defences against oncogenic processes. Fish studies could be a largely unexplored treasure trove for understanding the evolution and ecology of cancer, providing novel insights into the study of cancer and tumour suppression, in addition to fish evolution, life‐history trade‐offs, and ecology.
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Affiliation(s)
- Ciara Baines
- Institute of Ecology and Earth Sciences University of Tartu Tartu Estonia
- Estonian Marine Institute University of Tartu Tallinn Estonia
| | - Richard Meitern
- Institute of Ecology and Earth Sciences University of Tartu Tartu Estonia
| | - Randel Kreitsberg
- Institute of Ecology and Earth Sciences University of Tartu Tartu Estonia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences University of Tartu Tartu Estonia
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8
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Moreau J, Rabdeau J, Badenhausser I, Giraudeau M, Sepp T, Crépin M, Gaffard A, Bretagnolle V, Monceau K. Pesticide impacts on avian species with special reference to farmland birds: a review. Environ Monit Assess 2022; 194:790. [PMID: 36107257 DOI: 10.1007/s10661-022-10394-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
For decades, we have observed a major biodiversity crisis impacting all taxa. Avian species have been particularly well monitored over the long term, documenting their declines. In particular, farmland birds are decreasing worldwide, but the contribution of pesticides to their decline remains controversial. Most studies addressing the effects of agrochemicals are limited to their assessment under controlled laboratory conditions, the determination of lethal dose 50 (LD50) values and testing in a few species, most belonging to Galliformes. They often ignore the high interspecies variability in sensitivity, delayed sublethal effects on the physiology, behaviour and life-history traits of individuals and their consequences at the population and community levels. Most importantly, they have entirely neglected to test for the multiple exposure pathways to which individuals are subjected in the field (cocktail effects). The present review aims to provide a comprehensive overview for ecologists, evolutionary ecologists and conservationists. We aimed to compile the literature on the effects of pesticides on bird physiology, behaviour and life-history traits, collecting evidence from model and wild species and from field and lab experiments to highlight the gaps that remain to be filled. We show how subtle nonlethal exposure might be pernicious, with major consequences for bird populations and communities. We finally propose several prospective guidelines for future studies that may be considered to meet urgent needs.
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Affiliation(s)
- Jérôme Moreau
- Équipe Écologie Évolutive, UMR CNRS 6282 Biogéosciences, Université Bourgogne Franche-Comté, Dijon, France
- UMR CNRS 7372 Centre d'Études Biologiques de Chizé, La Rochelle Université, 79360, Villiers-en-Bois, France
| | - Juliette Rabdeau
- UMR CNRS 7372 Centre d'Études Biologiques de Chizé, La Rochelle Université, 79360, Villiers-en-Bois, France
| | - Isabelle Badenhausser
- Unité de Recherche Pluridisciplinaire Prairies Plantes Fourragères, INRAE, 86600, Lusignan, France
| | - Mathieu Giraudeau
- UMR IRD, CREEC, Université de Montpellier, 224-CNRS 5290, Montpellier, France
- Centre de Recherche en Écologie Et Évolution de La Sante (CREES), Montpellier, France
- Littoral Environnement Et Sociétés (LIENSs), UMR 7266, CNRS- La Rochelle Université, La Rochelle, France
| | - Tuul Sepp
- Department of Zoology, University of Tartu, Tartu, Estonia
| | - Malaury Crépin
- UMR CNRS 7372 Centre d'Études Biologiques de Chizé, La Rochelle Université, 79360, Villiers-en-Bois, France
| | - Agathe Gaffard
- UMR CNRS 7372 Centre d'Études Biologiques de Chizé, La Rochelle Université, 79360, Villiers-en-Bois, France
| | - Vincent Bretagnolle
- UMR CNRS 7372 Centre d'Études Biologiques de Chizé, La Rochelle Université, 79360, Villiers-en-Bois, France
- LTSER "Zone Atelier Plaine & Val de Sèvre", CNRS, 79360, Villiers-en-Bois, France
| | - Karine Monceau
- UMR CNRS 7372 Centre d'Études Biologiques de Chizé, La Rochelle Université, 79360, Villiers-en-Bois, France.
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Lind MA, Sepp T, Štšeglova K, Hõrak P. Antibiotic treatment increases yellowness of carotenoid feather coloration in male greenfinches (Chloris chloris). Sci Rep 2021; 11:13235. [PMID: 34168219 PMCID: PMC8225797 DOI: 10.1038/s41598-021-92598-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 06/04/2021] [Indexed: 12/17/2022] Open
Abstract
Carotenoid plumage coloration is an important sexually selected trait in many bird species. However, the mechanisms ensuring the honesty of signals based on carotenoid pigments remain unclear. It has recently been suggested that intestinal integrity, which is affected by gut parasites and microbiota and influences nutrient absorption and acquisition, mediates the relationship between carotenoid ornamentation and individual quality. Here, we test whether carotenoid plumage coloration in greenfinches (Chloris chloris) is affected by the treatment of an antibiotic or an antiparasitic drug. We captured wild greenfinches (N = 71) and administered anticoccidial medication toltrazuril (TOLTRA) to one group, antibiotic metronidazole (METRO) to the second group to target trichomonosis, and the third group received no medication. In the METRO group, feathers grown during the experiment had significantly higher chroma of yellow parts, but there was no effect of TOLTRA on feather chroma. The results suggest that METRO increased the efficiency of carotenoid modification or deposition to the feathers rather than nutrient acquisition and/or freed energy resources that could be invested in coloration. Alternatively, though not measured, METRO might have affected microbial community and host physiology as microbial metabolites can modulate mitochondrial and immune function.
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Affiliation(s)
- Mari-Ann Lind
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia.
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia
| | - Kristiina Štšeglova
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia
| | - Peeter Hõrak
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia
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10
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Baines C, Lerebours A, Thomas F, Fort J, Kreitsberg R, Gentes S, Meitern R, Saks L, Ujvari B, Giraudeau M, Sepp T. Linking pollution and cancer in aquatic environments: A review. Environ Int 2021; 149:106391. [PMID: 33515955 DOI: 10.1016/j.envint.2021.106391] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/23/2020] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
Due to the interconnectedness of aquatic ecosystems through the highly effective marine and atmospheric transport routes, all aquatic ecosystems are potentially vulnerable to pollution. Whilst links between pollution and increased mortality of wild animals have now been firmly established, the next steps should be to focus on specific physiological pathways and pathologies that link pollution to wildlife health deterioration. One of the pollution-induced pathologies that should be at the centre of attention in ecological and evolutionary research is cancer, as anthropogenic contamination has resulted in a rapid increase of oncogenic substances in natural habitats. Whilst wildlife cancer research is an emerging research topic, systematic reviews of the many case studies published over the recent decades are scarce. This research direction would (1) provide a better understanding of the physiological mechanisms connecting anthropogenic pollution to oncogenic processes in non-model organisms (reducing the current bias towards human and lab-animal studies in cancer research), and (2) allow us to better predict the vulnerability of different wild populations to oncogenic contamination. This article combines the information available within the scientific literature about cancer occurrences in aquatic and semi-aquatic species. For the first aim, we use available knowledge from aquatic species to suggest physiological mechanisms that link pollution and cancer, including main metabolic detoxification pathways, oxidative damage effects, infections, and changes to the microbiome. For the second aim, we determine which types of aquatic animals are more vulnerable to pollution-induced cancer, which types of pollution are mainly associated with cancer in aquatic ecosystems, and which types of cancer pollution causes. We also discuss the role of migration in exposing aquatic and semi-aquatic animals to different oncogenic pollutants. Finally, we suggest novel research avenues, including experimental approaches, analysis of the effects of pollutant cocktails and long-term chronic exposure to lower levels of pollutants, and the use of already published databases of gene expression levels in animals from differently polluted habitats.
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Affiliation(s)
- Ciara Baines
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia.
| | - Adelaide Lerebours
- LIttoral, ENvironnement et Sociétés (LIENSs), UMR7266, CNRS Université de La Rochelle, 2 rue Olympe de Gouges, 17042 La Rochelle Cedex, France
| | - Frederic Thomas
- CREEC/CREES, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France; MIVEGEC, UMR IRD/CNRS/UM 5290, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France
| | - Jerome Fort
- LIttoral, ENvironnement et Sociétés (LIENSs), UMR7266, CNRS Université de La Rochelle, 2 rue Olympe de Gouges, 17042 La Rochelle Cedex, France
| | - Randel Kreitsberg
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Sophie Gentes
- LIttoral, ENvironnement et Sociétés (LIENSs), UMR7266, CNRS Université de La Rochelle, 2 rue Olympe de Gouges, 17042 La Rochelle Cedex, France
| | - Richard Meitern
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Lauri Saks
- Estonian Marine Institute, Universty of Tartu, Mäealuse 14, 12618 Tallinn, Harju County, Estonia
| | - Beata Ujvari
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Waurn Ponds, VIC, Australia
| | - Mathieu Giraudeau
- LIttoral, ENvironnement et Sociétés (LIENSs), UMR7266, CNRS Université de La Rochelle, 2 rue Olympe de Gouges, 17042 La Rochelle Cedex, France; CREEC/CREES, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France; MIVEGEC, UMR IRD/CNRS/UM 5290, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
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11
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Sepp T, Webb E, Simpson RK, Giraudeau M, McGraw KJ, Hutton P. Light at night reduces digestive efficiency of developing birds: an experiment with king quail. Naturwissenschaften 2021; 108:4. [PMID: 33399962 DOI: 10.1007/s00114-020-01715-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 12/09/2020] [Accepted: 12/12/2020] [Indexed: 11/25/2022]
Abstract
Artificial light at night (ALAN) exposes animals to a novel environmental stimulus, one that is generally thought to be maladaptive. ALAN-related health problems have received little attention in non-model species, and we generally know little about the nutritional-physiological impacts of ALAN, especially in young animals. Here, we use a novel application of the acid steatocrit method to experimentally assess changes in digestive efficiency of growing king quail (Excalfactoria chinensis) in response to ALAN. Two weeks after hatching, quail were split into two groups (n = 20-21 per group): overnight-light-treated vs. overnight-dark-treated. When the chicks were 3 weeks old, the experimental group was exposed to weak blue light (ca. 0.3 lux) throughout the entire night for 6 consecutive weeks, until all the chicks had achieved sexual maturation. Fecal samples for assessing digestive efficiency were collected every week. We found that digestive efficiency of quail was reduced by ALAN at two time points from weeks 4 to 9 after hatching (quail reach adulthood by week 9). The negative effect of ALAN on digestion coincided with the period of fastest skeletal growth, which suggests that ALAN may reduce digestive efficiency when energetic demands of growth are at their highest. Interestingly, growth rate was not influenced by ALAN. This suggests that either the negative physiological impacts of ALAN may be concealed when food is provided ad libitum, the observed changes in digestive efficiency were too small to affect growth or condition, or that ALAN-exposed birds had reduced energy expenditure. Our results illustrate that the health impacts of ALAN on wild animals should not be restricted to traditional markers like body mass or growth rate, but instead on a wide array of integrated physiological traits.
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Affiliation(s)
- Tuul Sepp
- Department of Zoology, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia. .,School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.
| | - Emily Webb
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Richard K Simpson
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.,Department of Biological Sciences, University of Windsor, Windsor, ON, N9B 3P4, Canada
| | - Mathieu Giraudeau
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.,CREEC, MIVEGEC, UMR IRD/CNRS/UM 5290, 911 Avenue Agropolis, BP 6450134394, Montpellier Cedex 5, France
| | - Kevin J McGraw
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Pierce Hutton
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
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12
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Meitern R, Fort J, Giraudeau M, Rattiste K, Sild E, Sepp T. Age-dependent expression of cancer-related genes in a long-lived seabird. Evol Appl 2020; 13:1708-1718. [PMID: 32821278 PMCID: PMC7428815 DOI: 10.1111/eva.13024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/21/2020] [Accepted: 05/15/2020] [Indexed: 12/17/2022] Open
Abstract
Studies of model animals like mice and rats have led to great advances in our understanding of the process of tumorigenesis, but this line of study has less to offer for understanding the mechanisms of cancer resistance. Increasing the diversity of nonmodel species from the perspective of molecular mechanisms of natural cancer resistance can lead to new insights into the evolution of protective mechanisms against neoplastic processes and to a wider understanding of natural cancer defense mechanisms. Such knowledge could then eventually be harnessed for the development of human cancer therapies. We suggest here that seabirds are promising, albeit currently completely ignored candidates for studying cancer defense mechanisms, as they have a longer maximum life span than expected from their body size and rates of energy metabolism and may have thus evolved mechanisms to limit neoplasia progression, especially at older ages. We here apply a novel, intraspecific approach of comparing old and young seabirds for improving our understanding of aging and neoplastic processes in natural settings. We used the long-lived common gulls (Larus canus) for studying the age-related pattern of expression of cancer-related genes, based on transcriptome analysis and databases of orthologues of human cancer genes. The analysis of differently expressed cancer-related genes between young and old gulls indicated that similarly to humans, age is potentially affecting cancer risk in this species. Out of eleven differentially expressed cancer-related genes between the groups, three were likely artifactually linked to cancer. The remaining eight were downregulated in old gulls compared to young ones. The downregulation of five of them could be interpreted as a mechanism suppressing neoplasia risk and three as increasing the risk. Based on these results, we suggest that old gulls differ from young ones both from the aspect of cancer susceptibility and tumor suppression at the genetic level.
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Affiliation(s)
- Richard Meitern
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Jérôme Fort
- Littoral Environnement et Sociétés (LIENSs)UMR 7266 CNRS‐La Rochelle UniversitéLa RochelleFrance
| | | | - Kalev Rattiste
- Institute of Agricultural and Environmental SciencesEstonian University of Life SciencesTartuEstonia
| | - Elin Sild
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Tuul Sepp
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
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13
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Giraudeau M, Watson H, Powell D, Vincze O, Thomas F, Sepp T, Ujvari B, Le Loc'h G, Isaksson C. Will urbanisation affect the expression level of genes related to cancer of wild great tits? Sci Total Environ 2020; 714:135793. [PMID: 32018940 DOI: 10.1016/j.scitotenv.2019.135793] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Recent studies suggest that oncogenic processes (from precancerous lesions to metastatic cancers) are widespread in wild animal species, but their importance for ecosystem functioning is still underestimated by evolutionary biologists and animal ecologists. Similar to what has been observed in humans, environmental modifications that often place wild organisms into an evolutionary trap and/or exposes them to a cocktail of mutagenic and carcinogenic pollutants might favor cancer emergence and progression, if animals do not up-regulate their defenses against these pathologies. Here, we compared, for the first time, the expression of 59 tumor-suppressor genes in blood and liver tissues of urban and rural great tits (Parus major); urban conditions being known to favor cancer progression due to, among other things, exposure to chemical or light pollution. Contrary to earlier indications, once we aligned the transcriptome to the great tit genome, we found negligible differences in the expression of anti-cancer defenses between urban and rural birds in blood and liver. Our results indicate the higher expression of a single caretaker gene (i.e. BRCA1) in livers of rural compared to urban birds. We conclude that, while urban birds might be exposed to an environment favoring the development of oncogenic processes, they seem to not upregulate their cancer defenses accordingly and future studies should confirm this result by assessing more markers of cancer defenses. This may result in a mismatch that might predispose urban birds to higher cancer risk and future studies in urban ecology should take into account this, so far completely ignored, hazard.
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Affiliation(s)
- Mathieu Giraudeau
- Centre de Recherche en Écologie et Évolution de la Santé (CREES), Montpellier, France; CREEC/MIVEGEC (CNRS - IRD - Université de Montpellier), France.
| | - Hannah Watson
- Department of Biology, Lund University, SE-223 62 Lund, Sweden
| | - Daniel Powell
- Department of Biology, Lund University, SE-223 62 Lund, Sweden
| | - Orsolya Vincze
- Hungarian Department of Biology and Ecology, Evolutionary Ecology Group, Babeş-Bolyai University, Cluj-Napoca, Romania; Department of Tisza Research, MTA Centre for Ecological Research, Debrecen, Hungary
| | - Frederic Thomas
- Centre de Recherche en Écologie et Évolution de la Santé (CREES), Montpellier, France; CREEC/MIVEGEC (CNRS - IRD - Université de Montpellier), France
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Beata Ujvari
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Australia
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14
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Lind MA, Hõrak P, Sepp T, Meitern R. Corticosterone levels correlate in wild-grown and lab-grown feathers in greenfinches (Carduelis chloris) and predict behaviour and survival in captivity. Horm Behav 2020; 118:104642. [PMID: 31765655 DOI: 10.1016/j.yhbeh.2019.104642] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/24/2019] [Accepted: 11/13/2019] [Indexed: 10/25/2022]
Abstract
Level of corticosterone (CORT), which is a predominant glucocorticoid in birds, has become the main indicator for assessing the stress level of birds in ecological studies. Feather corticosterone (CORTf) provides information about corticosterone levels during feather growth, however, the underlying causes of individual variation of CORTf between individuals and individual persistency of CORTf are not yet fully understood. Therefore, this study addresses individual consistency in CORTf and the association of variation in CORTf with behaviour that results in damage to tail feathers. We studied relations between CORTf, plasma CORT, and behaviour in wild-caught male greenfinches in captivity. CORTf in wild-grown feathers correlated positively with CORTf in lab-grown feathers. CORTf levels were about 20% lower in lab-grown feathers than in those grown in the wild. Four birds that died in captivity had significantly higher average CORTf levels in wild-grown feathers than the survivors. Plasma CORT levels of two measurements taken in the lab seven days apart correlated positively, however, no correlations between plasma CORT and CORTf were found. In order to study the link between CORTf and behaviour, the extent of tail damage from flapping against cage bar was assessed. Contrary to our prediction, birds with higher CORTf had less tail damage. This study adds to the evidence that CORTf levels can be considered as informative markers of some persistent component of individual phenotypic quality that can predict survival under standardized laboratory conditions.
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Affiliation(s)
- Mari-Ann Lind
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia.
| | - Peeter Hõrak
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Richard Meitern
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
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15
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Giraudeau M, Heidinger B, Bonneaud C, Sepp T. Telomere shortening as a mechanism of long-term cost of infectious diseases in natural animal populations. Biol Lett 2019; 15:20190190. [PMID: 31113307 DOI: 10.1098/rsbl.2019.0190] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Pathogens are potent selective forces that can reduce the fitness of their hosts. While studies of the short-term energetic costs of infections are accumulating, the long-term costs have only just started to be investigated. Such delayed costs may, at least in part, be mediated by telomere erosion. This hypothesis is supported by experimental investigations conducted on laboratory animals which show that infection accelerates telomere erosion in immune cells. However, the generalizability of such findings to natural animal populations and to humans remains debatable. First, laboratory animals typically display long telomeres relative to their wild counterparts. Second, unlike humans and most wild animals, laboratory small-bodied mammals are capable of telomerase-based telomere maintenance throughout life. Third, the effect of infections on telomere shortening and ageing has only been studied using single pathogen infections, yet hosts are often simultaneously confronted with a range of pathogens in the wild. Thus, the cost of an infection in terms of telomere-shortening-related ageing in natural animal populations is likely to be strongly underestimated. Here, we discuss how investigations into the links between infection, immune response and tissue ageing are now required to improve our understanding of the long-term impact of disease.
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Affiliation(s)
| | - Britt Heidinger
- 2 Biological Sciences Department, North Dakota State University , Fargo , USA
| | - Camille Bonneaud
- 3 Centre for Ecology and Conservation, University of Exeter , Penryn , UK
| | - Tuul Sepp
- 4 Department of Zoology, University of Tartu , Tartu , Estonia
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16
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Urvik J, Rattiste K, Giraudeau M, Okuliarová M, Hõrak P, Sepp T. Age-specific patterns of maternal investment in common gull egg yolk. Biol Lett 2019; 14:rsbl.2018.0346. [PMID: 29997189 DOI: 10.1098/rsbl.2018.0346] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/19/2018] [Indexed: 01/19/2023] Open
Abstract
While the general patterns of age-specific changes in reproductive success are quite well established in long-lived animals, we still do not know if allocation patterns of maternally transmitted compounds are related to maternal age. We measured the levels of yolk testosterone, carotenoids and vitamins A and E in a population of known-aged common gulls (Larus canus) and found an age-specific pattern in yolk lutein and vitamin A concentrations. Middle-aged mothers allocated more of these substances to yolk compared to young and old mothers. These results can be explained through differences in age-specific foraging, absorption or deposition patterns of carotenoids and vitamins into yolk. If these molecules play a role in antioxidant defence and immune modulation, our results suggest a possible physiological pathway underlying the age-specific changes in reproductive success of long-lived birds in the wild.
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Affiliation(s)
- Janek Urvik
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Kalev Rattiste
- Chair of Biodiversity and Nature Tourism, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 51006, Tartu, Estonia
| | - Mathieu Giraudeau
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9FE, UK
| | - Monika Okuliarová
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15, Bratislava, Slovakia
| | - Peeter Hõrak
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
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17
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Giraudeau M, Sepp T, Ujvari B, Renaud F, Tasiemski A, Roche B, Capp JP, Thomas F. Differences in mutational processes and intra-tumour heterogeneity between organs: The local selective filter hypothesis. Evol Med Public Health 2019; 2019:139-146. [PMID: 31528343 PMCID: PMC6735757 DOI: 10.1093/emph/eoz017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 03/05/2019] [Indexed: 12/21/2022] Open
Abstract
Extensive diversity (genetic, cytogenetic, epigenetic and phenotypic) exists within and between tumours, but reasons behind these variations, as well as their consistent hierarchical pattern between organs, are poorly understood at the moment. We argue that these phenomena are, at least partially, explainable by the evolutionary ecology of organs' theory, in the same way that environmental adversity shapes mutation rates and level of polymorphism in organisms. Organs in organisms can be considered as specialized ecosystems that are, for ecological and evolutionary reasons, more or less efficient at suppressing tumours. When a malignancy does arise in an organ applying strong selection pressure on tumours, its constituent cells are expected to display a large range of possible surviving strategies, from hyper mutator phenotypes relying on bet-hedging to persist (high mutation rates and high diversity), to few poorly variable variants that become invisible to natural defences. In contrast, when tumour suppression is weaker, selective pressure favouring extreme surviving strategies is relaxed, and tumours are moderately variable as a result. We provide a comprehensive overview of this hypothesis. Lay summary: Different levels of mutations and intra-tumour heterogeneity have been observed between cancer types and organs. Anti-cancer defences are unequal between our organs. We propose that mostly aggressive neoplasms (i.e. higher mutational and ITH levels), succeed in emerging and developing in organs with strong defences.
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Affiliation(s)
- Mathieu Giraudeau
- CREEC, UMR IRD 224-CNRS 5290-Université de Montpellier, Montpellier, France
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia
| | - Beata Ujvari
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - François Renaud
- CREEC, UMR IRD 224-CNRS 5290-Université de Montpellier, Montpellier, France
| | - Aurélie Tasiemski
- Université de Lille-sciences et technologies, UMR 8198 Evo-Eco-Paleo, Villeneuve d'Ascq/CNRS/INSERM/CHU Lille, Institut Pasteur de Lille, U1019-Unité Mixte de Recherche 8204, Lille, France
| | - Benjamin Roche
- CREEC, UMR IRD 224-CNRS 5290-Université de Montpellier, Montpellier, France
- IRD, Sorbonne Université, UMMISCO, F-93143, Bondy, France
- Departamento de Etología, Fauna Silvestre y Animales de Laboratorio, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Jean-Pascal Capp
- INSA/Université Fédérale de Toulouse, Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, UMR CNRS 5504, UMR INRA 792, Toulouse, France
| | - Frédéric Thomas
- CREEC, UMR IRD 224-CNRS 5290-Université de Montpellier, Montpellier, France
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18
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Giraudeau M, Angelier F, Sepp T. Do Telomeres Influence Pace-of-Life-Strategies in Response to Environmental Conditions Over a Lifetime and Between Generations? Bioessays 2019; 41:e1800162. [DOI: 10.1002/bies.201800162] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 12/06/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Mathieu Giraudeau
- CREEC; 911 Avenue Agropolis; BP 6450134394 Montpellier Cedex 5 France
- MIVEGEC; UMR IRD/CNRS/UM 5290; 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5 France
| | - Frederic Angelier
- CNRS CEBC-ULR; UMR 7372; Villiers en Bois 79360 Beauvoir sur Niort France
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences; University of Tartu; Vanemuise 46 51014 Tartu Estonia
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19
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Sepp T, Ujvari B, Ewald PW, Thomas F, Giraudeau M. Urban environment and cancer in wildlife: available evidence and future research avenues. Proc Biol Sci 2019; 286:20182434. [PMID: 30963883 PMCID: PMC6367167 DOI: 10.1098/rspb.2018.2434] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/10/2018] [Indexed: 12/23/2022] Open
Abstract
While it is generally known that the risk of several cancers in humans is higher in urban areas compared with rural areas, cancer is often deemed a problem of human societies with modern lifestyles. At the same time, more and more wild animals are affected by urbanization processes and are faced with the need to adapt or acclimate to urban conditions. These include, among other things, increased exposure to an assortment of pollutants (e.g. chemicals, light and noise), novel types of food and new infections. According to the abundant literature available for humans, all of these factors are associated with an increased probability of developing cancerous neoplasias; however, the link between the urban environment and cancer in wildlife has not been discussed in the scientific literature. Here, we describe the available evidence linking environmental changes resulting from urbanization to cancer-related physiological changes in wild animals. We identify the knowledge gaps in this field and suggest future research avenues, with the ultimate aim of understanding how our modern lifestyle affects cancer prevalence in urbanizing wild populations. In addition, we consider the possibilities of using urban wild animal populations as models to study the association between environmental factors and cancer epidemics in humans, as well as to understand the evolution of cancer and defence mechanisms against it.
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Affiliation(s)
- Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Beata Ujvari
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Waurn Ponds, VIC, Australia
| | - Paul W. Ewald
- Department of Biology, University of Louisville, Louisville, KY 40292, USA
| | - Frédéric Thomas
- CREEC, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France
- MIVEGEC, UMR IRD/CNRS/UM 5290, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France
| | - Mathieu Giraudeau
- CREEC, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France
- MIVEGEC, UMR IRD/CNRS/UM 5290, 911 Avenue Agropolis, BP 6450134394 Montpellier Cedex 5, France
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20
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Urvik J, Rattiste K, Hõrak P, Meitern R, Sepp T. Uropygial gland size: a marker of phenotypic quality that shows no senescence in a long-lived seabird. Biogerontology 2018; 20:141-148. [PMID: 30415295 DOI: 10.1007/s10522-018-9782-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/07/2018] [Indexed: 10/27/2022]
Abstract
Studies of senescence in the wild have traditionally focused on traits like survival or fecundity. Although efforts to measure other salient phenotypic traits and markers of relevant physiological processes are rapidly increasing, traits related to self-maintenance remain understudied in the context of aging. Uropygial or preen gland is a holocrine gland, exclusive to birds, directly linked to self-maintenance of the quality of plumage. We measured the size of uropygial glands of common gulls (Larus canus) in a cross sectional manner in order to test whether it shows the similar age-related decline as reproductive traits previously recorded in this species. Gulls with larger glands started breeding earlier in the season, indicating that gland size is a marker of individual phenotypic quality. We found a senescent decline in the onset of breeding and the size of white wing patches, a sexually dimorphic ornamental trait, while in contrast, preen gland increased with advancing age. This finding supports the view of life-history theory that in long-lived species whose lifetime reproductive success depends heavily on lifespan, self-maintenance is prioritized over reproduction. Altogether our results support the concept that senescence in the wild can be asynchronous for traits related to maintenance versus reproduction.
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Affiliation(s)
- Janek Urvik
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia.
| | - Kalev Rattiste
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006, Tartu, Estonia
| | - Peeter Hõrak
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia
| | - Richard Meitern
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia.,School of Life Sciences, Arizona State University, Tempe, AZ, 85287-4501, USA
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21
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Sepp T, Desaivre S, Lendvai AZ, Németh J, McGraw KJ, Giraudeau M. Feather corticosterone levels are not correlated with health or plumage coloration in juvenile house finches. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Tuul Sepp
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise, Tartu, Estonia
| | - Steve Desaivre
- Department of Neuroscience, College of Natural Sciences, The University of Texas at Austin, Austin, TX, USA
| | - Adam Z Lendvai
- Department of Evolutionary Zoology and Human Biology, University of Debrecen, Nagyerdei, Debrecen, Hungary
| | - József Németh
- Department of Pharmacology and Pharmacotherapy, University of Debrecen, Debrecen, Egyetem, Hungary
| | - Kevin J McGraw
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Mathieu Giraudeau
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
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22
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Sepp T, McGraw KJ, Kaasik A, Giraudeau M. A review of urban impacts on avian life-history evolution: Does city living lead to slower pace of life? Glob Chang Biol 2018; 24:1452-1469. [PMID: 29168281 DOI: 10.1111/gcb.13969] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/23/2017] [Indexed: 06/07/2023]
Abstract
The concept of a pace-of-life syndrome describes inter- and intraspecific variation in several life-history traits along a slow-to-fast pace-of-life continuum, with long lifespans, low reproductive and metabolic rates, and elevated somatic defences at the slow end of the continuum and the opposite traits at the fast end. Pace-of-life can vary in relation to local environmental conditions (e.g. latitude, altitude), and here we propose that this variation may also occur along an anthropogenically modified environmental gradient. Based on a body of literature supporting the idea that city birds have longer lifespans, we predict that urban birds have a slower pace-of-life compared to rural birds and thus invest more in self maintenance and less in annual reproduction. Our statistical meta-analysis of two key traits related to pace-of-life, survival and breeding investment (clutch size), indicated that urban birds generally have higher survival, but smaller clutch sizes. The latter finding (smaller clutches in urban habitats) seemed to be mainly a characteristic of smaller passerines. We also reviewed urbanization studies on other traits that can be associated with pace-of-life and are related to either reproductive investment or self-maintenance. Though sample sizes were generally too small to conduct formal meta-analyses, published literature suggests that urban birds tend to produce lower-quality sexual signals and invest more in offspring care. The latter finding is in agreement with the adult survival hypothesis, proposing that higher adult survival prospects favour investment in fewer offspring per year. According to our hypothesis, differences in age structure should arise between urban and rural populations, providing a novel alternative explanation for physiological differences and earlier breeding. We encourage more research investigating how telomere dynamics, immune defences, antioxidants and oxidative damage in different tissues vary along the urbanization gradient, and suggest that applying pace-of-life framework to studies of variation in physiological traits along the urbanization gradient might be the next direction to improve our understanding of urbanization as an evolutionary process.
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Affiliation(s)
- Tuul Sepp
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Kevin J McGraw
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Ants Kaasik
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Mathieu Giraudeau
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, UK
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Vittecoq M, Giraudeau M, Sepp T, Marcogliese DJ, Klaassen M, Renaud F, Ujvari B, Thomas F. Turning natural adaptations to oncogenic factors into an ally in the war against cancer. Evol Appl 2018; 11:836-844. [PMID: 29928293 PMCID: PMC5999213 DOI: 10.1111/eva.12608] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/25/2018] [Indexed: 12/14/2022] Open
Abstract
Both field and experimental evolution studies have demonstrated that organisms naturally or artificially exposed to environmental oncogenic factors can, sometimes rapidly, evolve specific adaptations to cope with pollutants and their adverse effects on fitness. Although numerous pollutants are mutagenic and carcinogenic, little attention has been given to exploring the extent to which adaptations displayed by organisms living in oncogenic environments could inspire novel cancer treatments, through mimicking the processes allowing these organisms to prevent or limit malignant progression. Building on a substantial knowledge base from the literature, we here present and discuss this progressive and promising research direction, advocating closer collaboration between the fields of medicine, ecology, and evolution in the war against cancer.
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Affiliation(s)
- Marion Vittecoq
- Institut de Recherche de la Tour du Valat Arles France.,CREEC/MIVEGEC IRD CNRS University of Montpellier Montpellier France
| | - Mathieu Giraudeau
- School of Life Sciences Arizona State University Tempe AZ USA.,Centre for Ecology & Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
| | - Tuul Sepp
- School of Life Sciences Arizona State University Tempe AZ USA.,Department of Zoology University of Tartu Tartu Estonia
| | - David J Marcogliese
- Aquatic Contaminants Research Division Water Science and Technology Directorate Environment and Climate Change Canada St. Lawrence Centre Montreal QC Canada.,Fisheries and Oceans Canada St. Andrews Biological Station St. Andrews NB Canada
| | - Marcel Klaassen
- School of Life and Environmental Sciences Centre for Integrative Ecology Deakin University Deakin Vic. Australia
| | - François Renaud
- CREEC/MIVEGEC IRD CNRS University of Montpellier Montpellier France
| | - Beata Ujvari
- School of Life and Environmental Sciences Centre for Integrative Ecology Deakin University Deakin Vic. Australia.,School of Biological Sciences University of Tasmania Hobart TAS Australia
| | - Frédéric Thomas
- CREEC/MIVEGEC IRD CNRS University of Montpellier Montpellier France
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Urvik J, Meitern R, Rattiste K, Saks L, Hõrak P, Sepp T. Variation in the Markers of Nutritional and Oxidative State in a Long-Lived Seabird: Associations with Age and Longevity. Physiol Biochem Zool 2016; 89:417-40. [PMID: 27617362 DOI: 10.1086/688180] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Age-related declines in life-history traits have been widely observed in free-living animals. Several theories link senescence to oxidative stress. The aim of this study was to measure several widely used markers of oxidative and nutritional state in a long-lived seabird, the common gull (Larus canus), in order to assess the suitability of these markers for describing deterioration in physiological condition associated with chronological age and survival. Associations with longevity and individual consistency of these parameters over the years (repeatability) were also assessed. Senescence in fitness parameters was observed during the study period: in females, laying date and clutch mass were related to bird age in a curvilinear manner, with middle-aged birds breeding earlier and laying heavier eggs. The only parameter associated with aging processes was glutathione concentration in erythrocytes, which was lower in female birds with longer life spans. Of indexes of nutritional state, plasma triglyceride concentration showed a between-individual increase with age, suggesting selective mortality of birds with low levels. Additionally, total plasma protein levels of individual males increased with age. The mostly negative results of this study hint that the commonly used parameters of physiological condition and oxidative state used in this study do not adequately reflect an individual's long-term health condition. Alternatively, it is possible that in common gulls, senescence occurs in reproductive mechanisms but not in mechanisms responsible for maintaining an organism's redox balance, consistent with the idea that different aspects of an organism's physiological condition age at different rates. Significant interannual repeatability was detected in three plasma constituents-carotenoids, uric acid, and total protein-all of which can possibly be linked to variation in dietary habits.
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Moore FR, Cīrule D, Kivleniece I, Vrublevska J, Rantala MJ, Sild E, Sepp T, Hõrak P, Krama T, Krams I. Investment in a sexual signal results in reduced survival under extreme conditions in the male great tit (Parus major). Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1828-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Krams IA, Vrublevska J, Sepp T, Abolins-Abols M, Rantala MJ, Mierauskas P, Krama T. Sex-Specific Associations Between Nest Defence, Exploration and Breathing Rate in Breeding Pied Flycatchers. Ethology 2014. [DOI: 10.1111/eth.12222] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Indrikis A. Krams
- Institute of Systematic Biology; University of Daugavpils; Daugavpils Latvia
- Institute of Ecology and Earth Sciences; University of Tartu; Tartu Estonia
- Department of Biology; University of Turku; Turku Finland
| | - Jolanta Vrublevska
- Institute of Systematic Biology; University of Daugavpils; Daugavpils Latvia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences; University of Tartu; Tartu Estonia
| | | | | | - Pranas Mierauskas
- Department of Environment Policy; Mykolas Romeris University; Vilnius Lithuania
| | - Tatjana Krama
- Institute of Systematic Biology; University of Daugavpils; Daugavpils Latvia
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Hõrak P, Männiste M, Meitern R, Sild E, Saks L, Sepp T. Dexamethasone inhibits corticosterone deposition in feathers of greenfinches. Gen Comp Endocrinol 2013; 191:210-4. [PMID: 23856540 DOI: 10.1016/j.ygcen.2013.07.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/01/2013] [Accepted: 07/04/2013] [Indexed: 01/28/2023]
Abstract
Corticosterone (CORT) content of feathers is a potent source of information about activation of hypothalamus-pituitary-adrenal (HPA) axis during feather growth, which is used for assessment of well-being and stress history of individuals and populations in avian studies. However, little is known about factors affecting deposition of CORT into feathers and how feather CORT covaries with other markers of stress imposed upon individuals during feather growth. We addressed these questions by measuring CORT levels in feathers of wild-caught greenfinches (Carduelis chloris) brought into captivity. One tail feather was removed from all the birds upon arrival to the laboratory and the CORT levels of replacement feathers, grown in captivity were recorded. The birds were subjected to treatments of immune activation (by injection of phytohaemagglutinin) and synthetic glucocorticoid (dexamethasone, DEX) administration. Only DEX injection affected feather CORT levels. DEX-injected birds deposited on average 37% less of CORT in their feathers than saline-injected birds. Despite significant effects of DEX and immune activation treatments on differential leukocyte counts, we did not find any correlations between CORT and leukocyte hemoconcentrations or heterophil/lymphocyte ratios (a haematological index of stress), measured at three stages of feather growth. Our findings provide novel evidence that feather CORT levels are sensitive to manipulation of hormonal balance of birds, thereby supporting the diagnostic value of feather CORT measurements. However, we did not find any evidence about covariation between feather CORT and other markers of stress perceived during the period of feather growth. This calls for further research on information content of feather CORT, preferably in experiments manipulating more diverse array of psychological, immunological and abiotic stressors.
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Affiliation(s)
- Peeter Hõrak
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia.
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Meitern R, Sild E, Lind MA, Männiste M, Sepp T, Karu U, Hõrak P. Effects of Endotoxin and Psychological Stress on Redox Physiology, Immunity and Feather Corticosterone in Greenfinches. PLoS One 2013; 8:e67545. [PMID: 23805316 PMCID: PMC3689720 DOI: 10.1371/journal.pone.0067545] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 05/20/2013] [Indexed: 12/24/2022] Open
Abstract
Assessment of costs accompanying activation of immune system and related neuroendocrine pathways is essential for understanding the selective forces operating on these systems. Here we attempted to detect such costs in terms of disruption to redox balance and interference between different immune system components in captive wild-caught greenfinches (Carduelis chloris). Study birds were subjected to an endotoxin-induced inflammatory challenge and temporary exposure to a psychological stressor (an image of a predator) in a 2*2 factorial experiment. Injection of bacterial endotoxin resulted in up-regulation of two markers of antioxidant protection – erythrocyte glutathione, and plasma oxygen radical absorbance (OXY). These findings suggest that inflammatory responses alter redox homeostasis. However, no effect on markers of oxidative damage to proteins or DNA in erythrocytes could be detected. We found no evidence that the endotoxin injection interfered with antibody production against Brucella abortus antigen or the intensity of chronic coccidiosis. The hypothesis of within-immune system trade-offs as a cost of immunity was thus not supported in our model system. We showed for the first time that administration of endotoxin can reduce the level of corticosterone deposited into feathers. This finding suggests a down-regulation of the corticosterone secretion cascade due to an endotoxin-induced immune response, a phenomenon that has not been reported previously. Exposure to the predator image did not affect any of the measured physiological parameters.
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Affiliation(s)
- Richard Meitern
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Tartu, Estonia
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Affiliation(s)
- Marju Männiste
- Department of Zoology; Institute of Ecology and Earth Sciences; Tartu University; Tartu; Estonia
| | - Tuul Sepp
- Department of Zoology; Institute of Ecology and Earth Sciences; Tartu University; Tartu; Estonia
| | - Peeter Hõrak
- Department of Zoology; Institute of Ecology and Earth Sciences; Tartu University; Tartu; Estonia
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Krams IA, Suraka V, Rantala MJ, Sepp T, Mierauskas P, Vrublevska J, Krama T. Acute infection of avian malaria impairs concentration of haemoglobin and survival in juvenile altricial birds. J Zool (1987) 2013. [DOI: 10.1111/jzo.12043] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- I. A. Krams
- Institute of Ecology and Earth Sciences; University of Tartu; Tartu Estonia
- Institute of Systematic Biology; University of Daugavpils; Daugavpils Latvia
| | - V. Suraka
- Institute of Systematic Biology; University of Daugavpils; Daugavpils Latvia
- Rīga Stradins University; Rīga Latvia
| | - M. J. Rantala
- Department of Biology; University of Turku; Turku Finland
| | - T. Sepp
- Institute of Ecology and Earth Sciences; University of Tartu; Tartu Estonia
| | - P. Mierauskas
- Department of Environment Policy; Mykolas Romeris University; Vilnius Lithuania
| | - J. Vrublevska
- Institute of Systematic Biology; University of Daugavpils; Daugavpils Latvia
| | - T. Krama
- Institute of Systematic Biology; University of Daugavpils; Daugavpils Latvia
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Krams I, Vrublevska J, Cirule D, Kivleniece I, Krama T, Rantala MJ, Kaasik A, Hõrak P, Sepp T. Stress, Behaviour and Immunity in Wild-Caught Wintering Great Tits (Parus major). Ethology 2013. [DOI: 10.1111/eth.12075] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
| | - Jolanta Vrublevska
- Institute of Systematic Biology; University of Daugavpils; Daugavpils; Latvia
| | | | - Inese Kivleniece
- Institute of Systematic Biology; University of Daugavpils; Daugavpils; Latvia
| | - Tatjana Krama
- Institute of Systematic Biology; University of Daugavpils; Daugavpils; Latvia
| | - Markus J Rantala
- Section of Ecology; Department of Biology; University of Turku; Turku; Finland
| | - Ants Kaasik
- Institute of Ecology and Earth Sciences; University of Tartu; Tartu; Estonia
| | - Peeter Hõrak
- Institute of Ecology and Earth Sciences; University of Tartu; Tartu; Estonia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences; University of Tartu; Tartu; Estonia
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Sepp T, Karu U, Blount JD, Sild E, Männiste M, Hõrak P. Coccidian infection causes oxidative damage in greenfinches. PLoS One 2012; 7:e36495. [PMID: 22615772 PMCID: PMC3352913 DOI: 10.1371/journal.pone.0036495] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 04/03/2012] [Indexed: 12/22/2022] Open
Abstract
The main tenet of immunoecology is that individual variation in immune responsiveness is caused by the costs of immune responses to the hosts. Oxidative damage resulting from the excessive production of reactive oxygen species during immune response is hypothesized to form one of such costs. We tested this hypothesis in experimental coccidian infection model in greenfinches Carduelis chloris. Administration of isosporan coccidians to experimental birds did not affect indices of antioxidant protection (TAC and OXY), plasma triglyceride and carotenoid levels or body mass, indicating that pathological consequences of infection were generally mild. Infected birds had on average 8% higher levels of plasma malondialdehyde (MDA, a toxic end-product of lipid peroxidation) than un-infected birds. The birds that had highest MDA levels subsequent to experimental infection experienced the highest decrease in infection intensity. This observation is consistent with the idea that oxidative stress is a causative agent in the control of coccidiosis and supports the concept of oxidative costs of immune responses and parasite resistance. The finding that oxidative damage accompanies even the mild infection with a common parasite highlights the relevance of oxidative stress biology for the immunoecological research.
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Affiliation(s)
- Tuul Sepp
- Department of Zoology, Institute of Ecology and Earth Sciences, The Centre of Excellence FIBIR, Tartu University, Tartu, Estonia.
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Sepp T, Sild E, Blount JD, Männiste M, Karu U, Hõrak P. Individual Consistency and Covariation of Measures of Oxidative Status in Greenfinches. Physiol Biochem Zool 2012; 85:299-307. [DOI: 10.1086/664827] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
Carotenoid-based integument colouration is extremely widespread in the animal kingdom. It has been hypothesized that carotenoid colouration is used for communicating the health status of the bearers because carotenoids are efficient immunomodulators or antioxidants. However, the latter argument has been recently debated and the mechanisms by which carotenoids modulate immunity or oxidative balance are poorly known. We performed an experiment on wild-caught captive greenfinches, passerine birds with carotenoid-based plumage colouration, in order to test whether dietary carotenoid supplementation affects immune-stimulated oxidative burst of phagocytes in the whole blood and humoral immune response to a novel antigen, Brucella abortus (BA). Additionally, we tested whether immune stimulation with bacterial lipopolysaccharide (LPS) affects blood carotenoid levels. We thus tested the effects of carotenoids on the oxidative burst of phagocytes under neutral conditions and during in vivo immune challenge. LPS injection depleted plasma carotenoids, indicating involvement of these phytochemicals in the immune response. However, we did not find any evidence that manipulation of carotenoid intake had modulated anti-BA antibody production, LPS-stimulated oxidative burst of phagocytes, or basal levels of circulating reactive oxygen species. This indicates that carotenoid intake does not affect endogenous production of reactive oxygen species by immune cells. This finding is consistent with the view that carotenoids are unlikely to provide a direct link between oxidative stress and colouration. However, it remains to be tested whether the oxidative burst of phagocytes induced in our experiment actually inflicts oxidative damage and whether carotenoids play a role in the attenuation of such potential damages.
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Affiliation(s)
- Elin Sild
- Department of Zoology, Institute of Ecology and Earth Sciences, The Centre of Excellence FIBIR, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
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Sild E, Sepp T, Hõrak P. Behavioural trait covaries with immune responsiveness in a wild passerine. Brain Behav Immun 2011; 25:1349-54. [PMID: 21473910 DOI: 10.1016/j.bbi.2011.03.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 03/31/2011] [Accepted: 03/31/2011] [Indexed: 01/28/2023] Open
Abstract
Immune system is highly integrated with the nervous and endocrine systems, which is thought to result in covariation between behavioural syndromes and stress- and immune-associated diseases. Very little is known about the associations between behaviour and immune traits in wild animals. Here we describe such an association in passerine birds, the greenfinches (Carduelis chloris). When wild-caught greenfinches are brought into captivity, some individuals damage their tail feathers against cage walls due to excited behaviour, while others retain their feathers in intact condition. We show that damage to tail feathers was associated with flapping flight movements and the frequency of such flapping bouts was individually consistent over 57 days. Birds with intact tails, i.e., relatively 'calm' individuals mounted stronger antibody response to a novel Brucella abortus antigen and their circulating phagocytes were capable of producing stronger oxidative burst in response to stimulation with bacterial lipopolysaccharide in vitro. As the behavioural trait was assessed 13-25 days before measuring immune responsiveness, our results demonstrate that individuals' coping styles with captivity predicted how these individuals would respond to forthcoming immune challenges. This is a novel evidence about covariation between immune responsiveness and a behavioural trait in a wild-caught animal.
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Affiliation(s)
- Elin Sild
- Department of Zoology, Institute of Ecology and Earth Sciences, The Centre of Excellence FIBIR, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
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Sepp T, Karu U, Sild E, Männiste M, Hõrak P. Effects of carotenoids, immune activation and immune suppression on the intensity of chronic coccidiosis in greenfinches. Exp Parasitol 2010; 127:651-7. [PMID: 21176774 DOI: 10.1016/j.exppara.2010.12.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 11/17/2010] [Accepted: 12/14/2010] [Indexed: 11/29/2022]
Abstract
Allocation trade-offs of carotenoids between their use in the immune system and production of integumentary colouration have been suggested as a proximate mechanism maintaining honesty of signal traits. We tested how dietary carotenoid supplementation, immune activation and immune suppression affect intensity of coccidian infection in captive greenfinches Carduelis chloris, a passerine with carotenoid-based plumage. Immune activation with phytohaemagglutinin (PHA) decreased body mass among birds not supplemented with lutein, while among the carotenoid-fed birds, PHA had no effect on mass dynamics. Immune suppression with dexamethasone (DEX) induced loss of body mass and reduced the swelling response to PHA. DEX and PHA increased the concentration of circulating heterophils. Lutein supplementation increased plasma carotenoid levels but had no effect on the swelling response induced by PHA. PHA and DEX treatments did not affect plasma carotenoids. Immune stimulation by PHA suppressed the infection, but only among carotenoid-supplemented birds. Priming of the immune system can thus aid in suppressing chronic infection but only when sufficient amount of carotenoids is available. Our experiment shows the importance of carotenoids in immune response, but also the complicated nature of this impact, which could be the reason for inconsistent results in studies investigating the immunomodulatory effects of carotenoids. The findings about involvement of carotenoids in modulation of an immune response against coccidiosis suggest that carotenoid-based ornaments may honestly signal individuals' ability to manage chronic infections.
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Affiliation(s)
- Tuul Sepp
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia.
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Hõrak P, Sild E, Soomets U, Sepp T, Kilk K. Oxidative stress and information content of black and yellow plumage coloration: an experiment with greenfinches. J Exp Biol 2010; 213:2225-33. [PMID: 20543121 DOI: 10.1242/jeb.042085] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Carotenoid and melanin pigments in the plumage of birds are hypothesized to be sensitive to oxidative stress. We manipulated oxidative status of captive greenfinches (Carduelis chloris L.) by the administration of buthionine sulfoximine (BSO), a selective inhibitor of the synthesis of glutathione (GSH), an intracellular antioxidant. Half of the birds in the treated group, as well as in the control group, also received dietary carotenoid (lutein) supplementation. BSO treatment reduced erythrocyte GSH levels and caused oxidative damage as indicated by the increased concentration of plasma malondialdehyde (MDA), an end product of lipid peroxidation. BSO treatment also reduced the brightness (i.e. increased blackness) of the tips of tail feathers grown during the experiment. These results show that a low systemic GSH level is required for development of eumelanin plumage coloration and that such a low GSH level is also potentially dangerous for the organism. Carotenoid supplementation increased plasma carotenoid levels and chroma of the yellow parts of the feathers grown during the experiment. However, carotenoid supplementation did not reduce plasma MDA levels. Manipulation of GSH did not affect plasma carotenoids or carotenoid-based plumage coloration. These findings argue against the antioxidant function of lutein in vivo and carotenoid signaling of antioxidant status.
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Affiliation(s)
- Peeter Hõrak
- Department of Zoology, Institute of Ecology and Earth Sciences, The Centre of Excellence FIBIR, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
| | - Elin Sild
- Department of Zoology, Institute of Ecology and Earth Sciences, The Centre of Excellence FIBIR, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
| | - Ursel Soomets
- Department of Biochemistry, Medical Faculty; The Centre of Excellence for Translational Medicine, Tartu University, Ravila 19, 50411 Tartu, Estonia
| | - Tuul Sepp
- Department of Zoology, Institute of Ecology and Earth Sciences, The Centre of Excellence FIBIR, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
| | - Kalle Kilk
- Department of Biochemistry, Medical Faculty; The Centre of Excellence for Translational Medicine, Tartu University, Ravila 19, 50411 Tartu, Estonia
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Abstract
Ecophysiological research aiming at explaining the causes and consequences of variation in individual condition, health state, and allostasis is traditionally performed on captive animals under controlled laboratory conditions. The question about how captivity per se affects studied parameters is therefore of central importance for generalizing the information gained from such studies. We addressed this question by comparing various indexes of physiological condition of wintering greenfinches sampled in the wild and kept in captivity for different time periods. Bringing wild greenfinches into captivity did not result in systematic alteration in nine of 12 physiological parameters studied. Captive birds had consistently lower plasma carotenoid and uric acid levels than wild ones. Variation in differential leukocyte counts did not reveal any signs of elevated stress of birds kept in captivity. These results indicate that for a number of physiological parameters, information obtained from captive animals can be generalized to natural situations. Variance in traits most closely related to physical exercise capacity (body mass and hematocrit) were much lower in the wild than in captivity. These findings suggest that under harsh environmental conditions experienced by wild birds (i.e., predation threat, scarce resources), traits such as hematocrit and body mass are fine tuned by physiological trade-offs.
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Affiliation(s)
- Tuul Sepp
- Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia.
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39
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Affiliation(s)
- A L Wang
- Department of Pharmaceutical Chemistry, University of California, San Francisco, USA
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Abstract
Tuberous sclerosis (TSC) is an autosomal dominant disorder characterised by tumour-like malformations (hamartomas) of the brain, skin, and other organs, often associated with seizures and learning disability. There is genetic heterogeneity with loci for TSC on chromosomes 9q34 (TSC1) and 16p13.3 (TSC2). The recently cloned TSC1 gene has 23 exons spanning some 40 kb of genomic DNA with an 8.6 kb transcript. We now report the results of mutation screening by SSCP and heteroduplex analysis of genomic DNA for all 21 coding exons of TSC1 in 83 unrelated cases of tuberous sclerosis. TSC1 gene mutations were found in 16 of the 83 cases (19%). These comprised base substitutions, small insertions, or small deletions giving rise to six nonsense mutations, eight frameshifts, and two splice site mutations, all of which would be expected to result in a truncated or absent protein. In the 10 cases predicted to have TSC1 mutations by linkage analysis or loss of heterozygosity studies, the mutation was identified in eight (80%). In the remaining 73 unassigned cases, only eight mutations were found (11%). From these data we estimate that TSC1 mutations accounted for 24% of the cases in this sample (and an estimated 22% of all TSC cases). This contrasts with data from linkage studies suggesting that TSC1 and TSC2 mutations account for approximately equal numbers of families.
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Affiliation(s)
- J B Ali
- Department of Pathology, University of Cambridge, Addenbrooke's Hospital, UK
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Yates JR, van Bakel I, Sepp T, Payne SJ, Webb DW, Nevin NC, Green AJ. Female germline mosaicism in tuberous sclerosis confirmed by molecular genetic analysis. Hum Mol Genet 1997; 6:2265-9. [PMID: 9361032 DOI: 10.1093/hmg/6.13.2265] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have investigated a family in which three siblings with the autosomal dominant disorder tuberous sclerosis had unaffected parents. The family were typed for polymorphic markers spanning the two genes known to cause tuberous sclerosis located at 9q34 (TSC1) and 16p13.3 (TSC2). TSC1 markers showed different maternal and paternal haplotypes in affected children, excluding a mutation in TSC1 as the cause of the disease. For the TSC2 markers all the affected children had the same maternal and paternal haplotypes, as did three of their unaffected siblings. Mutation screening by RT-PCR and direct sequencing of the TSC2 gene identified a 4 bp insertion TACT following nucleotide 2077 in exon 18 which was present in the three affected children but not in five unaffected siblings or the parents. This mutation would cause a frameshift and premature termination at codon 703. Absence of the mutation in lymphocyte DNA from the parents was consistent with germline mosaicism and this was confirmed by our finding of identical chromosome 16 haplotypes in affected and unaffected siblings, providing unequivocal evidence of two different cell lines in the gametes. Molecular analysis of the TSC2 alleles present in the affected subjects showed that the mutation had been inherited from the mother. This is the first case of germline mosaicism in tuberous sclerosis proven by molecular genetic analysis and also the first example of female germline mosaicism for a characterized autosomal dominant gene mutation apparently not associated with somatic mosaicism.
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Affiliation(s)
- J R Yates
- Department of Pathology, University of Cambridge, Box 134 Addenbrooke's Hospital, Cambridge CB2 2QQ, UK.
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42
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van Bakel I, Sepp T, Ward S, Yates JR, Green AJ. Mutations in the TSC2 gene: analysis of the complete coding sequence using the protein truncation test (PTT). Hum Mol Genet 1997; 6:1409-14. [PMID: 9285776 DOI: 10.1093/hmg/6.9.1409] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Mutations in the TSC2 gene on chromosome 16p13.3 are responsible for approximately 50% of familial tuberous sclerosis (TSC). The gene has 41 small exons spanning 45 kb of genomic DNA and encoding a 5.5 kb mRNA. Large germline deletions of TSC2 occur in <5% of cases, and a number of small intragenic mutations have been described. We analysed mRNA from 18 unrelated cases of TSC for TSC2 mutations using the protein truncation test (PTT). Three cases were predicted to be TSC2 mutations on the basis of linkage analysis or because a hamartoma from the patient showed loss of heterozygosity for 16p13.3 markers. Three overlapping PCR products, covering the complete coding sequence of mRNA, were generated from lymphoblastoid cell lines, translated into 35S-methionine labelled protein, and analysed by SDS-PAGE. PCR products showing PTT shifts were directly sequenced, and mutations confirmed by restriction enzyme digestion where possible. Six PTT shifts were identified. Five of these were caused by mutations predicted to produce a truncated protein: (i) a sporadic case showed a 32 bp deletion in exon 11, and a mutant mRNA without exon 11 was produced; the normal exon 10 was also spliced out; (ii) a sporadic case had a 1 bp deletion in exon 12 (1634delT); (iii) a TSC2-linked mother and daughter pair had a G-->T transversion in exon 23 (G2715T) introducing a cryptic splice site causing a 29 bp truncation of mRNA from exon 23; (iv) a sporadic case showed a 2 bp deletion in exon 36; (v) a sporadic case showed a 1 bp insertion disrupting the donor splice site of exon 37 (5007+2insA), resulting in the use of an upstream exonic cryptic splice site to cause a 29 bp truncation of mRNA from exon 37. In one case, the PTT shift was explained by in-frame splicing out of exon 10, in the presence of a normal exon 10 genomic sequence. Alternative splicing of exon 10 of the TSC2 gene may be a normal variant. Three 3rd base substitution polymorphisms were also detected during direct sequencing of PCR products. Confirmed mutations were identified in 28% of the families studied and on the assumption that half of the sporadic cases should have TSC2 mutations, a crude estimate of the detection rate would be 60%. This compares favourably with other screening methods used for TSC2, notably SSCP, and since PTT involves much less work it may be the method of choice.
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Affiliation(s)
- I van Bakel
- Department of Pathology, University of Cambridge, UK
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43
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van Slegtenhorst M, de Hoogt R, Hermans C, Nellist M, Janssen B, Verhoef S, Lindhout D, van den Ouweland A, Halley D, Young J, Burley M, Jeremiah S, Woodward K, Nahmias J, Fox M, Ekong R, Osborne J, Wolfe J, Povey S, Snell RG, Cheadle JP, Jones AC, Tachataki M, Ravine D, Sampson JR, Reeve MP, Richardson P, Wilmer F, Munro C, Hawkins TL, Sepp T, Ali JB, Ward S, Green AJ, Yates JR, Kwiatkowska J, Henske EP, Short MP, Haines JH, Jozwiak S, Kwiatkowski DJ. Identification of the tuberous sclerosis gene TSC1 on chromosome 9q34. Science 1997; 277:805-8. [PMID: 9242607 DOI: 10.1126/science.277.5327.805] [Citation(s) in RCA: 1096] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the widespread development of distinctive tumors termed hamartomas. TSC-determining loci have been mapped to chromosomes 9q34 (TSC1) and 16p13 (TSC2). The TSC1 gene was identified from a 900-kilobase region containing at least 30 genes. The 8.6-kilobase TSC1 transcript is widely expressed and encodes a protein of 130 kilodaltons (hamartin) that has homology to a putative yeast protein of unknown function. Thirty-two distinct mutations were identified in TSC1, 30 of which were truncating, and a single mutation (2105delAAAG) was seen in six apparently unrelated patients. In one of these six, a somatic mutation in the wild-type allele was found in a TSC-associated renal carcinoma, which suggests that hamartin acts as a tumor suppressor.
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Affiliation(s)
- M van Slegtenhorst
- Department of Clinical Genetics, Erasmus University and University Hospital, Rotterdam, Netherlands
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44
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Affiliation(s)
- I van Bakel
- Department of Pathology, University of Cambridge, UK
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45
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Abstract
The caprine arthritis-encephalitis virus (CAEV) long terminal repeat (LTR) is activated by gamma interferon (IFN-gamma) in promonocytic cells. We have previously shown that a 70-bp element is necessary and sufficient for the response of the CAEV LTR to this cytokine. At the 5' end, this 70-bp IFN-gamma response element contains sequence similarity to the gamma activated site (GAS). Here we demonstrate that the putative GAS element in the CAEV LTR binds specifically to a cellular factor induced by IFN-gamma in promonocytic cells. Substitution mutations in this consensus sequence eliminate binding of the inducible factor. The GAS element from the 70-bp motif is sufficient to confer responsiveness to IFN-gamma using a heterologous minimal promoter. Consistent with the binding data, the same mutations in the GAS element eliminate responsiveness to IFN-gamma in the context of both a functional CAEV LTR and a heterologous promoter. The cellular factor that binds to the GAS element is present from 5 min to 14 h after stimulation with IFN-gamma. Binding of the nuclear factor to the GAS element in the CAEV LTR is inhibited by antibody directed against STAT1 (p91/84). Thus, the GAS sequence in the CAEV LTR is essential for the response to IFN-gamma and a STAT1-like factor binds to this site. The STAT-1 signaling pathway provides at least one mechanism for activation of the CAEV LTR by IFN-gamma in monocytes. These data are the first demonstration of a role for a STAT family member in the regulation of a viral promoter.
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Affiliation(s)
- T Sepp
- Department of Medicine, University of California-San Francisco, 94121, USA
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Abstract
We have previously described in tuberous sclerosis (TSC) hamartomas the phenomenon of loss of heterozygosity (LOH) for DNA markers in the region of both the TSC2 gene on chromosome 16p13.3 and the TSC1 gene on 9q34. We now describe the spectrum of LOH in 51 TSC hamartomas from 34 cases of TSC. DNA was extracted from leucocytes or normal paraffin embedded tissue, and from frozen paraffin embedded hamartoma tissue from the same patient. The samples were analysed for 11 markers spanning the TSC1 locus and nine markers spanning the TSC2 locus. Twenty-one of 51 hamartomas showed LOH (41%). There was significantly more LOH on 16p13.3, with 16 hamartomas showing LOH around TSC2, and five in the vicinity of TSC1. No hamartoma showed LOH for markers around both loci. All the areas of LOH on chromosome 9 were large, but the smallest region of overlap lay between the markers D9S149 and D9S114, providing independent evidence for the localisation of the TSC1 gene. These data show that LOH is a common finding in a wide range of hamartomas, affecting the same TSC locus in different lesions from the same patient but not affecting both loci. These data support the hypothesis that both the TSC genes act as tumour suppressors and that the manifestations of TSC in patients with germline TSC mutations rise from "second hit" somatic mutations inactivating the remaining normal copy of the TSC gene.
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Affiliation(s)
- T Sepp
- Department of Pathology, University of Cambridge, UK
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47
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Abstract
Tuberous sclerosis (TSC) is an autosomal dominant condition characterised by tumour-like malformations (hamartomas) in the brain and other organs. A proportion of hamartomas from patients with TSC show loss of heterozygosity (LOH) for DNA markers in the region of either the TSC1 gene on chromosome 9q34 or the TSC2 gene on 16p13.3. This implies that these lesions are clonal. We have studied X-chromosome inactivation, as a marker of clonality, in 13 hamartomas from females with TSC. The hamartomas comprised five renal angiomyolipomas, three fibromas and seven other lesions. In previous studies, four of the lesions showed LOH. A polymerase chain reaction assay was used to analyse differential methylation of an HpaII restriction site adjacent to the androgen-receptor triplet-repeat polymorphism on Xq11-12. In 12 of the lesions, there was a skewed inactivation pattern with one X chromosome being fully methylated and the other unmethylated. Normal tissue showed a random pattern of inactivation. These data confirm that most TSC hamartomas are clonal in origin. This is an intriguing finding, since these lesions are composed of more than one cell type.
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Affiliation(s)
- A J Green
- Dept. of Clinical Genetics, Addenbrooke's NHS Trust, Cambridge, UK
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48
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Abstract
Caprine arthritis-encephalitis virus (CAEV) is a lymphotropic lentivirus whose replication increases during monocyte maturation. We examined gene expression directed by the CAEV long terminal repeat (LTR) in a promonocytic cell line stimulated with several agents. Our results demonstrate that the CAEV LTR is activated by treatment of immature monocytes with gamma interferon (IFN-gamma) or a phorbol ester but not with tumor necrosis factor alpha or lipopolysaccharide. The cis-acting element in the LTR for the IFN-gamma response localizes to a duplicated 70-bp motif that contains an IFN-gamma response element, the gamma-activated site. One copy of the motif is necessary and sufficient for the response to IFN-gamma. Multiple copies contribute to basal transcriptional activity in the context of a heterologous promoter. This IFN-gamma response element in the CAEV LTR differs from the element required for the response to phorbol esters. Thus, activation of the CAEV LTR in monocytes that are stimulated by IFN-gamma, a cytokine that is secreted in response to viral infections, could contribute to conversion from latent to high-level viral replication in infected hosts.
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Affiliation(s)
- T Sepp
- Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446
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Abstract
Giardia lamblia virus (GLV) is a small nonenveloped double-stranded RNA virus that infects specifically the parasitic protozoan G. lamblia. Among the many collected strains of G. lamblia, a few turn out to be highly resistant to the virus infection. Two of these strains, Ac and JH, were subjected to electroporation with the RNA from GLV-infected G. lamblia WB strain. Subsequent studies indicated the presence of GLV double-stranded RNA and GLV protein in the electroporated and propagated cells. Virus particles, released by the transfected cells into the culture medium, were capable of infecting the virus-sensitive G. lamblia WB strain. When the WB cells were incubated with GLV at 4 degrees C and treated with the bifunctional cross-linking reagent disuccinimidyl suberate, little GLV protein was detectable inside the cells by immunofluorescent staining. However, patches of fluorescent granules were found on the membrane surface of the cells, suggesting cross-linking of the viruses with a certain membrane component(s). Similar treatment of the resistant strains Ac and JH showed no fluorescence either inside or outside of the cells. Two other closely related parasitic protozoa, Tritrichomonas foetus and Trichomonas vaginalis, cannot be infected by GLV via either viral infection or RNA transfection. The [35S]cysteine-labeled protein profiles in Triton X-114 extracts of G. lamblia WB, Ac, and JH were compared. The profile of the WB strain differs clearly from that of Ac and JH. It remains to be seen, however, whether this difference is related at all to the different susceptibilities to GLV infection.
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Affiliation(s)
- T Sepp
- Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446
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