13 results on '"Bin Yan"'
Search Results
2. From maternal glucocorticoid and thyroid hormones to epigenetic regulation of offspring gene expression: An experimental study in a wild bird species.
- Author
-
Hukkanen, Mikaela, Hsu, Bin‐Yan, Cossin‐Sevrin, Nina, Crombecque, Mélanie, Delaunay, Axelle, Hollmen, Lotta, Kaukonen, Riina, Konki, Mikko, Lund, Riikka, Marciau, Coline, Stier, Antoine, and Ruuskanen, Suvi
- Subjects
- *
THYROID hormone regulation , *GENETIC regulation , *GENE expression , *GLUCOCORTICOIDS , *THYROID hormones , *THYROID hormone receptors , *CHICKS - Abstract
Offspring phenotype at birth is determined by its genotype and the prenatal environment including exposure to maternal hormones. Variation in both maternal glucocorticoids and thyroid hormones can affect offspring phenotype, but the underlying molecular mechanisms, especially those contributing to long‐lasting effects, remain unclear. Epigenetic changes (such as DNA methylation) have been postulated as mediators of long‐lasting effects of early‐life environment. In this study, we determined the effects of elevated prenatal glucocorticoid and thyroid hormones on handling stress response (breath rate) as well as DNA methylation and gene expression of glucocorticoid receptor (GR) and thyroid hormone receptor (THR) in great tits (Parus major). Eggs were injected before incubation onset with corticosterone (the main avian glucocorticoid) and/or thyroid hormones (thyroxine and triiodothyronine) to simulate variation in maternal hormone deposition. Breath rate during handling and gene expression of GR and THR were evaluated 14 days after hatching. Methylation status of GR and THR genes was analyzed from the longitudinal blood cells sampled 7 and 14 days after hatching, as well as the following autumn. Elevated prenatal corticosterone level significantly increased the breath rate during handling, indicating an enhanced metabolic stress response. Prenatal corticosterone manipulation had CpG‐site‐specific effects on DNA methylation at the GR putative promoter region, while it did not significantly affect GR gene expression. GR expression was negatively associated with earlier hatching date and chick size. THR methylation or expression did not exhibit any significant relationship with the hormonal treatments or the examined covariates, suggesting that TH signaling may be more robust due to its crucial role in development. This study provides some support to the hypothesis suggesting that maternal corticosterone may influence offspring metabolic stress response via epigenetic alterations, yet their possible adaptive role in optimizing offspring phenotype to the prevailing conditions, context‐dependency, and the underlying molecular interplay needs further research. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Prenatal thyroid hormones accelerate postnatal growth and telomere shortening in wild great tits
- Author
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Bin-Yan Hsu, Nina Cossin-Sevrin, Antoine Stier, and Suvi Ruuskanen
- Subjects
telomere ,Physiology ,mitokondriot ,talitiainen ,Aquatic Science ,thyroid hormone ,mitochondria ,ikääntyminen ,developmental programming ,ageing ,Insect Science ,oxidative stress ,maternal effects ,telomeerit ,Animal Science and Zoology ,metabolism ,oksidatiivinen stressi ,aineenvaihdunta ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics - Abstract
Early-life environment is known to affect later-life health and disease, which could be mediated by the early-life programming of telomere length, a key hallmark of ageing. According to thefetal programming of telomere biology hypothesis, variation in prenatal exposure to hormones is likely to influence telomere length. Yet the contribution of key metabolic hormones,i.e. thyroid hormones (THs), has been largely ignored. We recently showed that in contrast to predictions, exposure to elevated prenatal THs increased postnatal telomere length in wild collared flycatchers, but the generality of such effect, its underlying proximate mechanisms and consequences on survival have not been investigated. We therefore conducted a comprehensive study evaluating the impact of THs on potential drivers of telomere dynamics (growth, post-natal THs, mitochondria and oxidative stress), telomere length and medium-term survival using wild great tits as a model system. While prenatal THs did not significantly affect telomere length a week after hatching (i.e. day 7), they influenced postnatal telomere shortening (i.e. shorter telomeres at day 14 and the following winter) but not apparent survival. Circulating THs, mitochondrial density or oxidative stress biomarkers were not significantly influenced, whereas TH-supplemented group showed accelerated growth, which may explain the observed delayed effect on telomeres. We discuss several alternative hypotheses that may explain the contrast with our previous findings in flycatchers. Given that shorter telomeres in early life tend to be carried until adulthood and are often associated with decreased survival prospects, the effects of prenatal THs on telomeres may have long-lasting effects on senescence.
- Published
- 2023
4. Manipulation of prenatal thyroid hormones does not affect growth or physiology in nestling Pied flycatchers
- Author
-
Suvi Ruuskanen, Ton G. G. Groothuis, Bin-Yan Hsu, Tom Sarraude, and Groothuis lab
- Subjects
Male ,STIMULATION ,food.ingredient ,bird ,Physiology ,Offspring ,maternal hormones ,030310 physiology ,growth ,Population ,OFFSPRING DEVELOPMENT ,RAT-LIVER ,Context (language use) ,Biology ,SUSCEPTIBILITY ,Biochemistry ,Injections ,03 medical and health sciences ,food ,Yolk ,TESTOSTERONE ,Animals ,oxidative stress ,Passeriformes ,European pied flycatcher ,education ,Ovum ,thyroid hormones ,0303 health sciences ,education.field_of_study ,Hatching ,YOLK ,Maternal effect ,Ficedula ,DNA ,biology.organism_classification ,Egg Yolk ,LIPID-PEROXIDATION ,SURVIVAL ,maternal effects ,Animal Science and Zoology ,Female - Abstract
Hormones transferred from mothers to their offspring are thought to be a tool for mothers to prepare their progeny for expected environmental conditions, thus increasing fitness. Thyroid hormones (THs) are crucial across vertebrates for embryonic and postnatal development and metabolism. Yet yolk THs have mostly been ignored in the context of hormone-mediated maternal effects. In addition, the few studies on maternal THs have yielded contrasting results that could be attributed to either species or environmental differences. In this study, we experimentally elevated yolk THs (within the natural range) in a wild population of a migratory passerine, the European pied flycatcher (Ficedula hypoleuca), and assessed the effects on hatching success, nestling survival, growth, and oxidative status (lipid peroxidation, antioxidant enzyme activity, and oxidative balance). We also sought to compare our results with those of a closely related species, the collared flycatcher (Ficedula albicolis), that has strong ecological and life-history similarities with our species. We found no effects of yolk THs on any of the responses measured. We could detect only a weak trend on growth: elevated yolk THs tended to increase growth during the second week after hatching. Our results contradict the findings of previous studies, including those of the collared flycatcher. However, differences in fledging success and nestling growth between both species in the same year suggest a context-dependent influence of the treatment. This study should stimulate more research on maternal effects mediated by THs and their potential context-dependent effects.
- Published
- 2020
5. Is maternal thyroid hormone deposition subject to a trade-off between self and egg because of iodine?
- Author
-
Suvi Ruuskanen, Bin-Yan Hsu, Ton G. G. Groothuis, Tom Sarraude, and Groothuis lab
- Subjects
0106 biological sciences ,Trade-offs ,Physiology ,Maternal effects ,01 natural sciences ,Maternal hypothyroidism ,ravintoaineet ,hormonaaliset vaikutukset ,0303 health sciences ,education.field_of_study ,kyyhkyt ,Thyroid ,Maternal effect ,Egg Yolk ,medicine.anatomical_structure ,embryonic structures ,Triiodothyronine ,Dietary Iodine ,maternal effects ,linnut ,Female ,Iodine ,Research Article ,Thyroid Hormones ,food.ingredient ,Offspring ,maternal hormones ,Population ,Aquatic Science ,Biology ,010603 evolutionary biology ,ravinto ,muninta ,jodi ,Birds ,03 medical and health sciences ,food ,Yolk ,medicine ,emot ,Animals ,Maternal hormones ,Columbidae ,education ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,lisääntymiskäyttäytyminen ,Maternal investment ,medicine.disease ,lisääntyminen ,hormonit ,Thyroxine ,trade-offs ,Insect Science ,birds ,Animal Science and Zoology ,Hormone ,maternal investment - Abstract
Maternal hormones constitute a key signalling pathway for mothers to shape offspring phenotype and fitness. Thyroid hormones (THs; triiodothyronine, T3; and thyroxine, T4) are metabolic hormones known to play crucial roles in embryonic development and survival in all vertebrates. During early developmental stages, embryos exclusively rely on exposure to maternal THs, and maternal hypothyroidism can cause severe embryonic maldevelopment. The TH molecule includes iodine, an element that cannot be synthesised by the organism. Therefore, TH production may become costly when environmental iodine availability is low. This may yield a trade-off for breeding females between allocating the hormones to self or to their eggs, potentially to the extent that it even influences the number of laid eggs. In this study, we investigated whether low dietary iodine may limit TH production and transfer to the eggs in a captive population of rock pigeons (Columba livia). We provided breeding females with an iodine-restricted (I−) diet or iodine-supplemented (I+) diet and measured the resulting circulating and yolk iodine and TH concentrations and the number of eggs laid. Our iodine-restricted diet successfully decreased both circulating and yolk iodine concentrations compared with the supplemented diet, but not circulating or yolk THs. This indicates that mothers may not be able to independently regulate hormone exposure for self and their embryos. However, egg production was clearly reduced in the I− group, with fewer females laying eggs. This result shows that restricted availability of iodine does induce a cost in terms of egg production. Whether females reduced egg production to preserve THs for themselves or to prevent embryos from exposure to low iodine and/or THs is as yet unclear., Summary: Restricted dietary iodine in captive rock pigeons reduces egg production in some females, thus inducing a trade-off between offspring quality and offspring quantity.
- Published
- 2021
6. Transient growth-enhancing effects of elevated maternal thyroid hormones at no apparent oxidative cost during early postnatal period
- Author
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Suvi Ruuskanen, Lars Gustafsson, Blandine Doligez, Bin-Yan Hsu, Department of Biology, University of Turku, University of Turku, Evolution, adaptation et comportement, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Division of Animal Ecology, and Uppsala University
- Subjects
0106 biological sciences ,food.ingredient ,Ficedula albicollis ,Offspring ,maternal hormones ,nestling growth ,Physiology ,medicine.disease_cause ,[SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy ,Zoologi ,010603 evolutionary biology ,01 natural sciences ,03 medical and health sciences ,food ,Yolk ,biology.animal ,medicine ,oxidative stress ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,thyroid hormones ,0303 health sciences ,biology ,Hatching ,[SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE] ,Fledge ,Maternal effect ,collared flycatcher ,biology.organism_classification ,Passerine ,ta1181 ,maternal effects ,Animal Science and Zoology ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Zoology ,Oxidative stress - Abstract
International audience; Maternal thyroid hormones (THs) have been proven crucial for embryonic development in humans, but their influence within the natural variation on wild animals remains unknown. So far the only two studies that experimentally investigated the potential fitness consequences of maternal THs in birds found inconsistent results. More studies are thus required to assess the general effects of maternal THs and their influences on more behavioral and physiological parameters. In this study, we experimentally elevated yolk TH content in a wild migratory passerine species, the collared flycatcher Ficedula albicollis, to investigate the effects on hatching success, nestling growth and oxidative stress. We found that TH-injected eggs had a higher hatching success, and the nestlings hatched from TH-injected eggs were heavier and larger than control nestlings, but only during the early postnatal period. These differences vanished by fledging. Nestlings from TH-injected eggs exhibited lower activity of the glutathione-s-transferase, a major antioxidant enzyme, than control nestlings at day 12, a few days before fledging, but they did not differ in oxidative damage and overall intracellular oxidative state. These results suggest that the early growth-enhancing effects incurred no observable oxidative stress. We hypothesize that such a transient growth-enhancing effect might be adaptive in advancing the development and maturation of the offspring so they are well-prepared in time for the upcoming migration. Further studies investigating whether such advancing effects can influence long-term fitness, will be more than valuable.
- Published
- 2019
7. No escape from mother's will
- Author
-
Bin-Yan Hsu, Ton G. G. Groothuis, Cor Dijkstra, Groothuis lab, and Dijkstra lab
- Subjects
0106 biological sciences ,0301 basic medicine ,medicine.medical_specialty ,food.ingredient ,Offspring ,maternal hormones ,media_common.quotation_subject ,Physiology ,RING-NECKED PHEASANT ,Biology ,010603 evolutionary biology ,01 natural sciences ,SEXUAL SELECTION ,reproduction ,03 medical and health sciences ,food ,prenatal testosterone exposure ,Yolk ,Internal medicine ,medicine ,Seasonal breeder ,Juvenile ,PRENATAL TESTOSTERONE ,long-term effects ,Ecology, Evolution, Behavior and Systematics ,media_common ,Sexual differentiation ,CONSEQUENCES ,GALLUS-GALLUS-DOMESTICUS ,POSTNATAL-GROWTH ,aggression ,PHASIANUS-COLCHICUS ,Maternal effect ,HORMONE DEPOSITION ,030104 developmental biology ,Endocrinology ,Sexual selection ,birds ,HOUSE SPARROWS ,maternal effects ,Animal Science and Zoology ,Reproduction ,YOLK ANDROGEN LEVELS ,courtship behaviour - Abstract
In many animal species, mothers expose their embryos to maternal hormones. This provides a powerful pathway for affecting offspring phenotype and a potential mechanism for adaptive nongenomic inheritance. This has been studied extensively in birds because the embryo develops outside the mother's body, facilitating experimental studies. Some studies have demonstrated that maternal yolk testosterone (T) can have long-lasting effects into the period after fledging. However, these results are based on offspring in the juvenile stage or their first breeding season only. The lack of data further into adulthood limits a better assessment of the fitness consequences of prenatal T. In a series of previous experiments in the rock pigeon, Columba livia, we manipulated yolk T levels using oil-injected eggs as controls. In the present study, we examined the reproductive behaviour of birds from these eggs when they were 1-3 years old and housed together in a large aviary. Our results showed that males from T-injected eggs were less aggressive and females from T-injected eggs laid lighter eggs than controls. Moreover, the experimental birds showed strongly disassortative mating with respect to hormone treatment. There were no indications of treatment effects on the process of sexual differentiation. Our results indicate that the effects of prenatal T do not diminish over age and may last far into adulthood, which should be taken into account in assessing the fitness consequences of maternal hormones. They may also stimulate new physiological and neurobiological studies on the mechanisms underlying such long-lasting effects of prenatal T exposure. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
- Published
- 2016
8. Manipulation of Prenatal Thyroid Hormones Does Not Affect Growth or Physiology in Nestling Pied Flycatchers.
- Author
-
Sarraude, Tom, Hsu, Bin-Yan, Groothuis, Ton G. G., and Ruuskanen, Suvi
- Subjects
- *
FLYCATCHERS , *PHYSIOLOGY , *EMBRYOLOGY , *BIRD growth , *THYROID hormones - Abstract
Hormones transferred from mothers to their offspring are thought to be a tool for mothers to prepare their progeny for expected environmental conditions, thus increasing fitness. Thyroid hormones (THs) are crucial across vertebrates for embryonic and postnatal development and metabolism. Yet yolk THs have mostly been ignored in the context of hormone-mediated maternal effects. In addition, the few studies on maternal THs have yielded contrasting results that could be attributed to either species or environmental differences. In this study, we experimentally elevated yolk THs (within the natural range) in a wild population of a migratory passerine, the European pied flycatcher (Ficedula hypoleuca), and assessed the effects on hatching success, nestling survival, growth, and oxidative status (lipid peroxidation, antioxidant enzyme activity, and oxidative balance). We also sought to compare our results with those of a closely related species, the collared flycatcher (Ficedula albicolis), that has strong ecological and life-history similarities with our species. We found no effects of yolk THs on any of the responses measured. We could detect only a weak trend on growth: elevated yolk THs tended to increase growth during the second week after hatching. Our results contradict the findings of previous studies, including those of the collared flycatcher. However, differences in fledging success and nestling growth between both species in the same year suggest a context-dependent influence of the treatment. This study should stimulate more research on maternal effects mediated by THs and their potential context-dependent effects. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
9. Maternal adjustment or constraint: Differential effects of food availability on maternal deposition of macro-nutrients, steroids and thyroid hormones in rock pigeon eggs
- Author
-
Veerle Darras, Cor Dijkstra, Bonnie de Vries, Ton G. G. Groothuis, Bin-Yan Hsu, Groothuis lab, Dijkstra lab, and Neurobiology
- Subjects
0106 biological sciences ,0301 basic medicine ,YOLK TESTOSTERONE ,BRAIN-DEVELOPMENT ,medicine.medical_specialty ,food.ingredient ,Offspring ,food conditions ,Zoology ,GULL EGGS ,Biology ,010603 evolutionary biology ,01 natural sciences ,Bird egg ,03 medical and health sciences ,ANDROGENS ,food ,Yolk ,Internal medicine ,yolk hormone deposition ,BIRD EGGS ,medicine ,ZEBRA FINCH ,egg mass ,Zebra finch ,Ecology, Evolution, Behavior and Systematics ,Original Research ,Nature and Landscape Conservation ,thyroid hormones ,Ecology ,Maternal effect ,Brood ,EMBRYONIC-DEVELOPMENT ,AVIAN EGGS ,030104 developmental biology ,Endocrinology ,embryonic structures ,maternal effects ,FINCHES TAENIOPYGIA-GUTTATA ,Oviparity ,MASS VARIATION ,Hormone - Abstract
In oviparous species like birds, eggs provide the direct environment in which embryos are developing. Mothers may adjust different egg components in different ways in reaction to environmental cues either to adjust offspring development or because of constraints. In this study, we investigated the effects of food quality and quantity before and during egg laying on three different aspects of egg quality: macro-nutrients (egg and yolk mass), androgens (testosterone and androstenedione), and thyroid hormones (3,5,3'-triiodothyronine, T3 and l-thyroxine, T4), using the rock pigeon (Columba livia). As expected, egg and yolk mass were significantly reduced for the eggs laid under the poor-food condition, indicating a maternal trade-off between offspring and self in allocating important resources. We did not find any significant change in yolk testosterone or their within-clutch pattern over the laying sequence. This is consistent with the fact that, in contrast with nutrients, these hormones are not costly to produce, but does not support the hypothesis that they play a role in adjusting brood size to food conditions. In contrast, we found that T3 levels were higher in the egg yolks under the poor-food condition whereas the total T4 content was lower. This change could be related to the fact that iodine, the critical constituent of thyroid hormones, might be a limiting factor in the production of this hormone. Given the knowledge that food restriction usually lead to reduction of circulating T3 levels, our results suggested that avian mothers can independently regulate its concentrations in their eggs from their own circulation. The study demonstrates that environmentally induced maternal effects via the egg can be a result of a combination of constrained resources and unconstrained signals and that thyroid hormones might be an interesting case of both. Therefore, this hormone and the interplay of different maternal effects on the offspring phenotype deserve much more attention. ispartof: Ecology and Evolution vol:6 issue:2 pages:397-411 ispartof: location:England status: published
- Published
- 2016
10. No escape from mother's will: effects of maternal testosterone on offspring reproductive behaviour far into adulthood.
- Author
-
Hsu, Bin-Yan, Dijkstra, Cor, and Groothuis, Ton G.G.
- Subjects
- *
TESTOSTERONE , *ANIMAL reproduction , *PHENOTYPES , *EMBRYOS , *ANIMAL aggression , *NEUROBIOLOGY - Abstract
In many animal species, mothers expose their embryos to maternal hormones. This provides a powerful pathway for affecting offspring phenotype and a potential mechanism for adaptive nongenomic inheritance. This has been studied extensively in birds because the embryo develops outside the mother's body, facilitating experimental studies. Some studies have demonstrated that maternal yolk testosterone (T) can have long-lasting effects into the period after fledging. However, these results are based on offspring in the juvenile stage or their first breeding season only. The lack of data further into adulthood limits a better assessment of the fitness consequences of prenatal T. In a series of previous experiments in the rock pigeon, Columba livia , we manipulated yolk T levels using oil-injected eggs as controls. In the present study, we examined the reproductive behaviour of birds from these eggs when they were 1–3 years old and housed together in a large aviary. Our results showed that males from T-injected eggs were less aggressive and females from T-injected eggs laid lighter eggs than controls. Moreover, the experimental birds showed strongly disassortative mating with respect to hormone treatment. There were no indications of treatment effects on the process of sexual differentiation. Our results indicate that the effects of prenatal T do not diminish over age and may last far into adulthood, which should be taken into account in assessing the fitness consequences of maternal hormones. They may also stimulate new physiological and neurobiological studies on the mechanisms underlying such long-lasting effects of prenatal T exposure. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
11. Maternal adjustment or constraint: differential effects of food availability on maternal deposition of macro-nutrients, steroids and thyroid hormones in rock pigeon eggs.
- Author
-
Hsu, Bin-Yan, Dijkstra, Cor, Darras, Veerle M., Vries, Bonnie, and Groothuis, Ton G.G.
- Subjects
- *
BIRD reproduction , *EMBRYOS , *OVIPARITY , *PIGEONS , *THYROID hormones , *BIRDS - Abstract
In oviparous species like birds, eggs provide the direct environment in which embryos are developing. Mothers may adjust different egg components in different ways in reaction to environmental cues either to adjust offspring development or because of constraints. In this study, we investigated the effects of food quality and quantity before and during egg laying on three different aspects of egg quality: macro-nutrients (egg and yolk mass), androgens (testosterone and androstenedione), and thyroid hormones (3,5,3′-triiodothyronine, T3 and l-thyroxine, T4), using the rock pigeon ( Columba livia). As expected, egg and yolk mass were significantly reduced for the eggs laid under the poor-food condition, indicating a maternal trade-off between offspring and self in allocating important resources. We did not find any significant change in yolk testosterone or their within-clutch pattern over the laying sequence. This is consistent with the fact that, in contrast with nutrients, these hormones are not costly to produce, but does not support the hypothesis that they play a role in adjusting brood size to food conditions. In contrast, we found that T3 levels were higher in the egg yolks under the poor-food condition whereas the total T4 content was lower. This change could be related to the fact that iodine, the critical constituent of thyroid hormones, might be a limiting factor in the production of this hormone. Given the knowledge that food restriction usually lead to reduction of circulating T3 levels, our results suggested that avian mothers can independently regulate its concentrations in their eggs from their own circulation. The study demonstrates that environmentally induced maternal effects via the egg can be a result of a combination of constrained resources and unconstrained signals and that thyroid hormones might be an interesting case of both. Therefore, this hormone and the interplay of different maternal effects on the offspring phenotype deserve much more attention. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
12. Transient growth‐enhancing effects of elevated maternal thyroid hormones at no apparent oxidative cost during early postnatal period.
- Author
-
Hsu, Bin‐Yan, Doligez, Blandine, Gustafsson, Lars, and Ruuskanen, Suvi
- Subjects
- *
THYROID hormones , *EMBRYOLOGY , *BIRD behavior , *BIRD physiology , *PASSERIFORMES - Abstract
Maternal thyroid hormones (THs) have been proven crucial for embryonic development in humans, but their influence within the natural variation on wild animals remains unknown. So far the only two studies that experimentally investigated the potential fitness consequences of maternal THs in birds found inconsistent results. More studies are thus required to assess the general effects of maternal THs and their influences on more behavioral and physiological parameters. In this study, we experimentally elevated yolk TH content in a wild migratory passerine species, the collared flycatcher Ficedula albicollis, to investigate the effects on hatching success, nestling growth and oxidative stress. We found that TH‐injected eggs had a higher hatching success, and the nestlings hatched from TH‐injected eggs were heavier and larger than control nestlings, but only during the early postnatal period. These differences vanished by fledging. Nestlings from TH‐injected eggs exhibited lower activity of the glutathione‐s‐transferase, a major antioxidant enzyme, than control nestlings at day 12, a few days before fledging, but they did not differ in oxidative damage and overall intracellular oxidative state. These results suggest that the early growth‐enhancing effects incurred no observable oxidative stress. We hypothesize that such a transient growth‐enhancing effect might be adaptive in advancing the development and maturation of the offspring so they are well‐prepared in time for the upcoming migration. Further studies investigating whether such advancing effects can influence long‐term fitness, will be more than valuable. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
13. From maternal glucocorticoid and thyroid hormones to epigenetic regulation of offspring gene expression: An experimental study in a wild bird species
- Author
-
Mikaela Hukkanen, Bin‐Yan Hsu, Nina Cossin‐Sevrin, Mélanie Crombecque, Axelle Delaunay, Lotta Hollmen, Riina Kaukonen, Mikko Konki, Riikka Lund, Coline Marciau, Antoine Stier, and Suvi Ruuskanen
- Subjects
epigenetics ,hormone ,maternal effects ,methylation ,Parus major ,prenatal ,Evolution ,QH359-425 - Abstract
Abstract Offspring phenotype at birth is determined by its genotype and the prenatal environment including exposure to maternal hormones. Variation in both maternal glucocorticoids and thyroid hormones can affect offspring phenotype, but the underlying molecular mechanisms, especially those contributing to long‐lasting effects, remain unclear. Epigenetic changes (such as DNA methylation) have been postulated as mediators of long‐lasting effects of early‐life environment. In this study, we determined the effects of elevated prenatal glucocorticoid and thyroid hormones on handling stress response (breath rate) as well as DNA methylation and gene expression of glucocorticoid receptor (GR) and thyroid hormone receptor (THR) in great tits (Parus major). Eggs were injected before incubation onset with corticosterone (the main avian glucocorticoid) and/or thyroid hormones (thyroxine and triiodothyronine) to simulate variation in maternal hormone deposition. Breath rate during handling and gene expression of GR and THR were evaluated 14 days after hatching. Methylation status of GR and THR genes was analyzed from the longitudinal blood cells sampled 7 and 14 days after hatching, as well as the following autumn. Elevated prenatal corticosterone level significantly increased the breath rate during handling, indicating an enhanced metabolic stress response. Prenatal corticosterone manipulation had CpG‐site‐specific effects on DNA methylation at the GR putative promoter region, while it did not significantly affect GR gene expression. GR expression was negatively associated with earlier hatching date and chick size. THR methylation or expression did not exhibit any significant relationship with the hormonal treatments or the examined covariates, suggesting that TH signaling may be more robust due to its crucial role in development. This study provides some support to the hypothesis suggesting that maternal corticosterone may influence offspring metabolic stress response via epigenetic alterations, yet their possible adaptive role in optimizing offspring phenotype to the prevailing conditions, context‐dependency, and the underlying molecular interplay needs further research.
- Published
- 2023
- Full Text
- View/download PDF
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