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Masoero G, Gencheva KG, Ioset N, Bersier LF, Tettamanti F, Bize P. Shrinking Alpine chamois: higher spring temperatures over the last 27 years in Switzerland are linked to a 3 kg reduction in body mass of yearlings. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231295. [PMID: 38481987 PMCID: PMC10933532 DOI: 10.1098/rsos.231295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/29/2024] [Accepted: 02/09/2024] [Indexed: 04/26/2024]
Abstract
Although climate change is considered to be partly responsible for the size change observed in numerous species, the relevance of this hypothesis for ungulates remains debated. We used body mass measurements of 5635 yearlings (i.e. 1.5 years old) of Alpine chamois (Rupicapra rupicapra) harvested in September in the Swiss Alps (Ticino canton) from 1992 to 2018. In our study area, during this period, yearlings shrank by ca 3 kg while temperatures between May and July rose by 1.7°C. We identified that warmer temperatures during birth and the early suckling period (9 May to 2 July in the year of birth) had the strongest impact on yearling mass. Further analyses of year-detrended mass and temperature data indicate that this result was not simply due to changes in both variables over years, but that increases in temperature during this particularly sensitive time window for development and growth are responsible for the decrease in body mass of yearling chamois. Altogether, our results suggest that rising temperatures in the Alpine regions could significantly affect the ecology and evolution of this wild ungulate.
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Affiliation(s)
- Giulia Masoero
- Department of Biology, University of Ottawa, Ottawa, Canada
- Swiss Ornithological Institute, Seerose 1, Sempach6204, Switzerland
| | | | - Noémie Ioset
- Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg, Switzerland
| | - Louis-Félix Bersier
- Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg, Switzerland
| | - Federico Tettamanti
- Studio alpino Tettamanti, La Campagna d Zora 15, Lodano6678, Switzerland
- Ufficio della Caccia e della Pesca del Cantone Ticino, Bellinzona, Switzerland
| | - Pierre Bize
- Swiss Ornithological Institute, Seerose 1, Sempach6204, Switzerland
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
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2
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Folkertsma R, Charbonnel N, Henttonen H, Heroldová M, Huitu O, Kotlík P, Manzo E, Paijmans JLA, Plantard O, Sándor AD, Hofreiter M, Eccard JA. Genomic signatures of climate adaptation in bank voles. Ecol Evol 2024; 14:e10886. [PMID: 38455148 PMCID: PMC10918726 DOI: 10.1002/ece3.10886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 11/17/2023] [Accepted: 12/18/2023] [Indexed: 03/09/2024] Open
Abstract
Evidence for divergent selection and adaptive variation across the landscape can provide insight into a species' ability to adapt to different environments. However, despite recent advances in genomics, it remains difficult to detect the footprints of climate-mediated selection in natural populations. Here, we analysed ddRAD sequencing data (21,892 SNPs) in conjunction with geographic climate variation to search for signatures of adaptive differentiation in twelve populations of the bank vole (Clethrionomys glareolus) distributed across Europe. To identify the loci subject to selection associated with climate variation, we applied multiple genotype-environment association methods, two univariate and one multivariate, and controlled for the effect of population structure. In total, we identified 213 candidate loci for adaptation, 74 of which were located within genes. In particular, we identified signatures of selection in candidate genes with functions related to lipid metabolism and the immune system. Using the results of redundancy analysis, we demonstrated that population history and climate have joint effects on the genetic variation in the pan-European metapopulation. Furthermore, by examining only candidate loci, we found that annual mean temperature is an important factor shaping adaptive genetic variation in the bank vole. By combining landscape genomic approaches, our study sheds light on genome-wide adaptive differentiation and the spatial distribution of variants underlying adaptive variation influenced by local climate in bank voles.
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Affiliation(s)
- Remco Folkertsma
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, Faculty of ScienceUniversity of PotsdamPotsdamGermany
- Comparative Cognition Unit, Messerli Research InstituteUniversity of Veterinary Medicine ViennaViennaAustria
| | | | | | - Marta Heroldová
- Department of Forest Ecology, FFWTMendel University in BrnoBrnoCzech Republic
| | - Otso Huitu
- Natural Resources Institute FinlandHelsinkiFinland
| | - Petr Kotlík
- Laboratory of Molecular Ecology, Institute of Animal Physiology and GeneticsCzech Academy of SciencesLiběchovCzech Republic
| | - Emiliano Manzo
- Fondazione Ethoikos, Convento dell'OsservanzaRadicondoliItaly
| | - Johanna L. A. Paijmans
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, Faculty of ScienceUniversity of PotsdamPotsdamGermany
- Present address:
Evolutionary Ecology Group, Department of ZoologyUniversity of CambridgeCambridgeUK
| | | | - Attila D. Sándor
- HUN‐RENClimate Change: New Blood‐Sucking Parasites and Vector‐Borne Pathogens Research GroupBudapestHungary
- Department of Parasitology and ZoologyUniversity of Veterinary MedicineBudapestHungary
- Department of Parasitology and Parasitic DiseasesUniversity of Agricultural Sciences and Veterinary MedicineCluj‐NapocaRomania
| | - Michael Hofreiter
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, Faculty of ScienceUniversity of PotsdamPotsdamGermany
| | - Jana A. Eccard
- Animal Ecology, Institute for Biochemistry and Biology, Faculty of ScienceBerlin‐Brandenburg Institute for Biodiversity ResearchUniversity of PotsdamPotsdamGermany
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3
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Grosiak M, Koteja P, Hambly C, Speakman JR, Sadowska ET. Limits to sustained energy intake. XXXIV. Can the heat dissipation limit (HDL) theory explain reproductive aging? J Exp Biol 2024; 227:jeb246592. [PMID: 38264846 DOI: 10.1242/jeb.246592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 01/11/2024] [Indexed: 01/25/2024]
Abstract
According to the heat dissipation limit (HDL) theory, reproductive performance is limited by the capacity to dissipate excess heat. We tested the novel hypotheses that (1) the age-related decline in reproductive performance is due to an age-related decrease of heat dissipation capacity and (2) the limiting mechanism is more severe in animals with high metabolic rates. We used bank voles (Myodes glareolus) from lines selected for high swim-induced aerobic metabolic rate, which have also increased basal metabolic rate, and unselected control lines. Adult females from three age classes - young (4 months), middle-aged (9 months) and old (16 months) - were maintained at room temperature (20°C), and half of the lactating females were shaved to increase heat dissipation capacity. Old females from both selection lines had a decreased litter size, mass and growth rate. The peak-lactation average daily metabolic rate was higher in shaved than in unshaved mothers, and this difference was more profound among old than young and middle-aged voles (P=0.02). In females with large litters, milk production tended to be higher in shaved (least squares mean, LSM±s.e.: 73.0±4.74 kJ day-1) than in unshaved voles (61.8±4.78 kJ day-1; P=0.05), but there was no significan"t effect of fur removal on the growth rate [4.47±2.29 g (4 days-1); P=0.45]. The results provide mixed support of the HDL theory and no support for the hypotheses linking the differences in reproductive aging with either a deterioration in thermoregulatory capability or genetically based differences in metabolic rate.
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Affiliation(s)
- Marta Grosiak
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow 30-387, Poland
| | - Paweł Koteja
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow 30-387, Poland
| | - Catherine Hambly
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - John R Speakman
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
| | - Edyta T Sadowska
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow 30-387, Poland
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4
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Khera M, Arbuckle K, Mwanguhya F, Kyabulima S, Mwesige K, Businge R, Blount JD, Cant MA, Nichols HJ. Small increases in ambient temperature reduce offspring body mass in an equatorial mammal. Biol Lett 2023; 19:20230328. [PMID: 37990567 PMCID: PMC10715294 DOI: 10.1098/rsbl.2023.0328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/02/2023] [Indexed: 11/23/2023] Open
Abstract
Human-induced climate change is leading to temperature rises, along with increases in the frequency and intensity of heatwaves. Many animals respond to high temperatures through behavioural thermoregulation, for example by resting in the shade, but this may impose opportunity costs by reducing foraging time (therefore energy supply), and so may be most effective when food is abundant. However, the heat dissipation limit (HDL) theory proposes that even when energy supply is plentiful, high temperatures can still have negative effects. This is because dissipating excess heat becomes harder, which limits processes that generate heat such as lactation. We tested predictions from HDL on a wild, equatorial population of banded mongooses (Mungos mungo). In support of the HDL theory, higher ambient temperatures led to lighter pups, and increasing food availability made little difference to pup weight under hotter conditions. This suggests that direct physiological constraints rather than opportunity costs of behavioural thermoregulation explain the negative impact of high temperatures on pup growth. Our results indicate that climate change may be particularly important for equatorial species, which often experience high temperatures year-round so cannot time reproduction to coincide with cooler conditions.
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Affiliation(s)
- Monil Khera
- Department of Biosciences, Swansea University, Swansea SA2 8PP, UK
| | - Kevin Arbuckle
- Department of Biosciences, Swansea University, Swansea SA2 8PP, UK
| | - Francis Mwanguhya
- Banded Mongoose Research Project, Queen Elizabeth National Park, Kasese District, Uganda
| | - Solomon Kyabulima
- Banded Mongoose Research Project, Queen Elizabeth National Park, Kasese District, Uganda
| | - Kenneth Mwesige
- Banded Mongoose Research Project, Queen Elizabeth National Park, Kasese District, Uganda
| | - Robert Businge
- Banded Mongoose Research Project, Queen Elizabeth National Park, Kasese District, Uganda
| | | | - Michael A. Cant
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
| | - Hazel J. Nichols
- Department of Biosciences, Swansea University, Swansea SA2 8PP, UK
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5
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Yang R, Cao J, Speakman JR, Zhao Z. Limits to sustained energy intake. XXXIII. Thyroid hormones play important roles in milk production but do not define the heat dissipation limit in Swiss mice. J Exp Biol 2023; 226:jeb245393. [PMID: 37767758 DOI: 10.1242/jeb.245393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 09/22/2023] [Indexed: 09/29/2023]
Abstract
The limits to sustained energy intake set physiological upper boundaries that affect many aspects of human and animal performance. The mechanisms underlying these limits, however, remain unclear. We exposed Swiss mice to either supplementary thyroid hormones (THs) or the inhibitor methimazole during lactation at 21 or 32.5°C, and measured food intake, resting metabolic rate (RMR), milk energy output (MEO), serum THs and mammary gland gene expression of females, and litter size and mass of their offspring. Lactating females developed hyperthyroidism following exposure to supplementary THs at 21°C, but they did not significantly change body temperature, asymptotic food intake, RMR or MEO, and litter and mass were unaffected. Hypothyroidism, induced by either methimazole or 32.5°C exposure, significantly decreased asymptotic food intake, RMR and MEO, resulting in significantly decreased litter size and litter mass. Furthermore, gene expression of key genes in the mammary gland was significantly decreased by either methimazole or heat exposure, including gene expression of THs and prolactin receptors, and Stat5a and Stat5b. This suggests that endogenous THs are necessary to maintain sustained energy intake and MEO. Suppression of the thyroid axis seems to be an essential aspect of the mechanism by which mice at 32.5°C reduce their lactation performance to avoid overheating. However, THs do not define the upper limit to sustained energy intake and MEO at peak lactation at 21°C. Another, as yet unknown, factor prevents supplementary thyroxine exerting any stimulatory metabolic impacts on lactating mice at 21°C.
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Affiliation(s)
- Rui Yang
- College of Life and Environmental Science, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- College of Life and Environmental Science, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China
| | - John R Speakman
- Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Zhijun Zhao
- College of Life and Environmental Science, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China
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6
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Hoffman JM, Schmitz B, Pfabe JU, Ohrnberger SA, Valencak TG. Lactating SKH-1 furless mice prioritize own comfort over growth of their pups. J Comp Physiol B 2023; 193:453-459. [PMID: 37243858 PMCID: PMC10985496 DOI: 10.1007/s00360-023-01498-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 05/10/2023] [Accepted: 05/16/2023] [Indexed: 05/29/2023]
Abstract
Lactation is the most energetically demanding physiological process that occurs in mammalian females, and as a consequence of this energy expenditure, lactating females produce an enormous amount of excess heat. This heat is thought to limit the amount of milk a mother produces, and by improving heat dissipation, females may improve their milk production and offspring quality. Here we used SKH-1 hairless mice as a natural model of improved heat dissipation. Lactating mothers were given access to a secondary cage to rest away from their pups, and this secondary cage was kept either at room temperature (22 °C) in the control rounds or cooled to 8 °C in the experimental groups. We hypothesized that the cold exposure would maximize the heat dissipation potential, leading to increased milk production and healthier pups even in the hairless mouse model. However, we found the opposite, where cold exposure allowed mothers to eat more food, but they produced smaller weight pups at the end of lactation. Our results suggest that mothers prioritize their own fitness, even if it lowers the fitness of their offspring in this particular mouse strain. This maternal-offspring trade-off is interesting and requires future studies to understand the full interaction of maternal effects and offspring fitness in the light of the heat dissipation limitation.
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Affiliation(s)
- Jessica M Hoffman
- Department of Biological Sciences, Augusta University, 1120 15th Street, Augusta, GA, 30912, USA
| | - Britta Schmitz
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Johannes U Pfabe
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Sarah A Ohrnberger
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Teresa G Valencak
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
- College of Animal Sciences, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, People's Republic of China.
- Agency for Health and Food Safety, Spargelfeldstrasse 191, 1220, Vienna, Austria.
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7
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Fur removal promotes an earlier expression of involution-related genes in mammary gland of lactating mice. J Comp Physiol B 2023; 193:171-192. [PMID: 36650338 PMCID: PMC9992052 DOI: 10.1007/s00360-023-01474-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/31/2022] [Accepted: 01/06/2023] [Indexed: 01/19/2023]
Abstract
Peak lactation occurs when milk production is at its highest. The factors limiting peak lactation performance have been subject of intense debate. Milk production at peak lactation appears limited by the capacity of lactating females to dissipate body heat generated as a by-product of processing food and producing milk. As a result, manipulations that enhance capacity to dissipate body heat (such as fur removal) increase peak milk production. We investigated the potential correlates of shaving-induced increases in peak milk production in laboratory mice. By transcriptomic profiling of the mammary gland, we searched for the mechanisms underlying experimentally increased milk production and its consequences for mother-young conflict over weaning, manifested by advanced or delayed involution of mammary gland. We demonstrated that shaving-induced increases in milk production were paradoxically linked to reduced expression of some milk synthesis-related genes. Moreover, the mammary glands of shaved mice had a gene expression profile indicative of earlier involution relative to unshaved mice. Once provided with enhanced capacity to dissipate body heat, shaved mice were likely to rear their young to independence faster than unshaved mothers.
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8
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Weeks BC, Klemz M, Wada H, Darling R, Dias T, O'Brien BK, Probst CM, Zhang M, Zimova M. Temperature, size and developmental plasticity in birds. Biol Lett 2022; 18:20220357. [PMID: 36475424 PMCID: PMC9727665 DOI: 10.1098/rsbl.2022.0357] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
As temperatures increase, there is growing evidence that species across much of the tree of life are getting smaller. These climate change-driven size reductions are often interpreted as a temporal analogue of the observation that individuals within a species tend to be smaller in the warmer parts of the species' range. For ectotherms, there has been a broad effort to understand the role of developmental plasticity in temperature-size relationships, but in endotherms, this mechanism has received relatively little attention in favour of selection-based explanations. We review the evidence for a role of developmental plasticity in warming-driven size reductions in birds and highlight insulin-like growth factors as a potential mechanism underlying plastic responses to temperature in endotherms. We find that, as with ectotherms, changes in temperature during development can result in shifts in body size in birds, with size reductions associated with warmer temperatures being the most frequent association. This suggests developmental plasticity may be an important, but largely overlooked, mechanism underlying warming-driven size reductions in endotherms. Plasticity and natural selection have very different constraining forces, thus understanding the mechanism linking temperature and body size in endotherms has broad implications for predicting future impacts of climate change on biodiversity.
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Affiliation(s)
- Brian C. Weeks
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
| | - Madeleine Klemz
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
| | - Haruka Wada
- Department of Biological Sciences, Auburn University, Auburn, AL, USA
| | - Rachel Darling
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
| | - Tiffany Dias
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
| | - Bruce K. O'Brien
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
| | - Charlotte M. Probst
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
| | - Mingyu Zhang
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
| | - Marketa Zimova
- School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA
- Department of Biology, Appalachian State University, Boone, NC, USA
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9
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Czenze ZJ, Noakes MJ, Wojciechowski MS. Home is where the heat is: Thermoregulation of European bats inhabiting artificial roosts and the threat of heat waves. J Appl Ecol 2022. [DOI: 10.1111/1365-2664.14230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Zenon J. Czenze
- Centre for Behavioural and Physiological Ecology University of New England Armidale NSW Australia
| | - Matthew J. Noakes
- Department of Vertebrate Zoology and Ecology Nicolaus Copernicus University Toruń Poland
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10
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van Rosmalen L, Riedstra B, Beemster N, Dijkstra C, Hut RA. Differential temperature effects on photoperiodism in female voles: A possible explanation for declines in vole populations. Mol Ecol 2022; 31:3360-3373. [PMID: 35398940 PMCID: PMC9325516 DOI: 10.1111/mec.16467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/20/2022] [Accepted: 03/28/2022] [Indexed: 11/30/2022]
Abstract
Many mammalian species use photoperiod as a predictive cue to time seasonal reproduction. In addition, metabolic effects on the reproductive axis may also influence seasonal timing, especially in female small, short-lived mammals. To get a better understanding of how annual cycling environmental cues impact reproductive function and plasticity in small, short-lived herbivores with different geographic origins, we investigated the mechanisms underlying integration of temperature in the photoperiodic-axis regulating female reproduction in a Northern vole species (tundra vole, Microtus oeconomus) and in a Southern vole species (common vole, Microtus arvalis). We show that photoperiod and temperature interact to determine appropriate physiological responses; there is species-dependent annual variation in the sensitivity to temperature for reproductive organ development. In common voles, temperature can overrule photoperiodical spring-programmed responses, with reproductive organ mass being higher at 10°C than at 21°C, whereas in autumn they are less sensitive to temperature. These findings are in line with our census data, showing an earlier onset of spring reproduction in cold springs, while reproductive offset in autumn is synchronized to photoperiod. The reproductive organs of tundra voles were relatively insensitive to temperature, whereas hypothalamic gene expression was generally upregulated at 10°C. Thus, both vole species use photoperiod, whereas only common voles use temperature as a cue to control spring reproduction, which indicates species-specific reproductive strategies. Due to global warming, spring reproduction in common voles will be delayed, perhaps resulting in shorter breeding seasons and thus declining populations, as observed throughout Europe.
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Affiliation(s)
- Laura van Rosmalen
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Present address:
Salk Institute for Biological StudiesLa JollaCaliforniaUSA
| | - Bernd Riedstra
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Nico Beemster
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Present address:
Altenburg & Wymenga Ecological ConsultantsFeanwâldenThe Netherlands
| | - Cor Dijkstra
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Roelof A. Hut
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
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11
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Bai D, Wan X, Li G, Wan X, Guo Y, Shi D, Zhang Z. Factors influencing range contraction of a rodent herbivore in a steppe grassland over the past decades. Ecol Evol 2022; 12:e8546. [PMID: 35222948 PMCID: PMC8843818 DOI: 10.1002/ece3.8546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 12/13/2021] [Accepted: 12/17/2021] [Indexed: 11/08/2022] Open
Abstract
Climate warming and human disturbance are known to be key drivers in causing range contraction of many species, but quantitative assessment on their distinctive and interactive effects on local disappearance is still rare. In this study, we examined the association of climate warming and human disturbance stressors with local disappearance probability of Brandt's voles (Lasiopodomys brandtii) in a steppe grassland in northern China. We used logistic generalized additive models to quantify the relationship between local disappearance probability of Brandt's voles and environmental variables. The year following the last observation year was used to estimate the disappearance threshold of Brandt's voles. We projected the distribution change of Brandt's voles under future climate warming scenarios. We found climate warming attributed to local disappearance and range contraction for southern populations of Brandt's voles from 1971 to 2020. Human stressors and high vegetation coverage increased the probability of local disappearance of voles in years of abundant precipitation. The southern boundary retreated northward at a speed of 99.0 km per decade with the temperature rise of 0.36°C. The disappearance threshold of maximum air temperature of Brandt's voles in the warmest month (27.50 ± 1.61°C) was similar to the lower critical temperature of its thermal neutral zone. Our study suggests that the rapid climate change over the past decades contributed to the range contraction of its southern boundary of this keystone species in the steppe grassland of China. It is necessary to take actions to preserve the isolated populations of Brandt's voles from the effects of accelerated climate change and human disturbance.
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Affiliation(s)
- Defeng Bai
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
- CAS Center for Excellence in Biotic Interactions University of Chinese Academy of Sciences Beijing China
| | - Xinru Wan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
- CAS Center for Excellence in Biotic Interactions University of Chinese Academy of Sciences Beijing China
| | - Guoliang Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
- CAS Center for Excellence in Biotic Interactions University of Chinese Academy of Sciences Beijing China
| | - Xinrong Wan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
| | - Yongwang Guo
- National Agro‐tech Extension and Service Center Beijing China
| | - Dazhao Shi
- College of Plant Protection China Agricultural University Beijing China
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
- CAS Center for Excellence in Biotic Interactions University of Chinese Academy of Sciences Beijing China
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12
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Simons MJP, Sebire M, Verhulst S, Groothuis TGG. Androgen Elevation Accelerates Reproductive Senescence in Three-Spined Stickleback. Front Cell Dev Biol 2022; 9:752352. [PMID: 34977010 PMCID: PMC8718761 DOI: 10.3389/fcell.2021.752352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
Costs of reproduction shape the life-history evolution of investment in current and future reproduction and thereby aging. Androgens have been proposed to regulate the physiology governing these investments. Furthermore, androgens are hypothesized to play a central role in carotenoid-dependent sexual signaling, regulating how much carotenoids are diverted to ornamentation and away from somatic maintenance, increasing oxidative stress, and accelerating aging. We investigated these relationships in male three-spined stickleback in which we elevated 11-ketotestosterone and supplied vitamin E, an antioxidant, in a 2 × 2 design. Androgen elevation shortened the time stickleback maintained reproductive activities. We suspect that this effect is caused by 11-ketotestosterone stimulating investment in current reproduction, but we detected no evidence for this in our measurements of reproductive effort: nest building, body composition, and breeding coloration. Carotenoid-dependent coloration was even slightly decreased by 11-ketotestosterone elevation and was left unaffected by vitamin E. Red coloration correlated with life expectancy and reproductive capacity in a quadratic manner, suggesting overinvestment of the individuals exhibiting the reddest bellies. In contrast, blue iris color showed a negative relationship with survival, suggesting physiological costs of producing this aspect of nuptial coloration. In conclusion, our results support the hypothesis that androgens regulate investment in current versus future reproduction, yet the precise mechanisms remain elusive. The quadratic relationships between sexual signal expression and aspects of quality have wider consequences for how we view sexual selection on ornamentation and its relationship with aging.
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Affiliation(s)
- Mirre J P Simons
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Marion Sebire
- The Centre for Environment, Fisheries and Aquaculture Science, Weymouth, United Kingdom
| | - Simon Verhulst
- Behavioural Biology, Centre for Behaviour and Neuroscience, University of Groningen, Groningen, Netherlands
| | - Ton G G Groothuis
- Behavioural Biology, Centre for Behaviour and Neuroscience, University of Groningen, Groningen, Netherlands
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13
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van Rosmalen L, van Dalum J, Appenroth D, Roodenrijs RTM, de Wit L, Hazlerigg DG, Hut RA. Mechanisms of temperature modulation in mammalian seasonal timing. FASEB J 2021; 35:e21605. [PMID: 33913553 DOI: 10.1096/fj.202100162r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/25/2021] [Accepted: 04/02/2021] [Indexed: 12/15/2022]
Abstract
Global warming is predicted to have major effects on the annual time windows during which species may successfully reproduce. At the organismal level, climatic shifts engage with the control mechanism for reproductive seasonality. In mammals, laboratory studies on neuroendocrine mechanism emphasize photoperiod as a predictive cue, but this is based on a restricted group of species. In contrast, field-oriented comparative analyses demonstrate that proximate bioenergetic effects on the reproductive axis are a major determinant of seasonal reproductive timing. The interaction between proximate energetic and predictive photoperiodic cues is neglected. Here, we focused on photoperiodic modulation of postnatal reproductive development in common voles (Microtus arvalis), a herbivorous species in which a plastic timing of breeding is well documented. We demonstrate that temperature-dependent modulation of photoperiodic responses manifest in the thyrotrophin-sensitive tanycytes of the mediobasal hypothalamus. Here, the photoperiod-dependent expression of type 2 deiodinase expression, associated with the summer phenotype was enhanced by 21°C, whereas the photoperiod-dependent expression of type 3 deiodinase expression, associated with the winter phenotype, was enhanced by 10°C in spring voles. Increased levels of testosterone were found at 21°C, whereas somatic and gonadal growth were oppositely affected by temperature. The magnitude of these temperature effects was similar in voles photoperiodical programmed for accelerated maturation (ie, born early in the breeding season) and in voles photoperiodical programmed for delayed maturation (ie, born late in the breeding season). The melatonin-sensitive pars tuberalis was relatively insensitive to temperature. These data define a mechanistic hierarchy for the integration of predictive temporal cues and proximate thermo-energetic effects in mammalian reproduction.
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Affiliation(s)
- Laura van Rosmalen
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Jayme van Dalum
- Arctic Seasonal Timekeeping initiative (ASTI), Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Daniel Appenroth
- Arctic Seasonal Timekeeping initiative (ASTI), Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Renzo T M Roodenrijs
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Lauren de Wit
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - David G Hazlerigg
- Arctic Seasonal Timekeeping initiative (ASTI), Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Roelof A Hut
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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14
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Bao MH, Xu XM, Huo DL, Cao J, Zhao ZJ. The effect of aggression II: Acclimation to a high ambient temperature reduces territorial aggression in male striped hamsters (Cricetulus barabensis). Horm Behav 2021; 132:104993. [PMID: 33991799 DOI: 10.1016/j.yhbeh.2021.104993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/02/2021] [Accepted: 05/03/2021] [Indexed: 12/01/2022]
Abstract
Thyroid hormones have a profound influence on development, cellular differentiation and metabolism, and are also suspected of playing a role in aggression. We measured territorial aggression, body temperature (Tb) and serum thyroid hormones levels of male striped hamsters (Cricetulus barabensis) acclimated to either cold (5 °C), cool (21 °C) or hot (34 °C) ambient temperatures. The effects of methimazole on territorial aggression, food intake, metabolic rate and serum thyroid hormone levels, were also examined. Territorial aggression was significantly lower in male hamsters acclimated to the hot temperature compared to those acclimated to the cool or cold temperatures. Tb significantly increased during aggressive territorial interactions with intruders but did not significantly differ among the three temperature treatments. Serum T3, T4 and cortisol levels of hamsters acclimated to 34 °C were significantly lower than those acclimated to 21 °C. In addition to significantly reducing territorial aggression, treatment with methimazole also significantly reduced serum T3 and T4 levels, Tb and metabolic rate. These results suggest that exposure to high temperatures reduces the capacity of hamsters to dissipate heat causing them to lower their metabolic rate, which, in turn, causes them to reduce territorial aggression to prevent hyperthermia. The lower metabolic rate mediated by down-regulated thyroid hormones inhibits territorial aggression and could thereby determine the outcome of territorial conflicts.
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Affiliation(s)
- Meng-Huan Bao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Xiao-Ming Xu
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Da-Liang Huo
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China.
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15
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Huang YX, Li HH, Wang L, Min HX, Xu JQ, Wu SL, Cao J, Zhao ZJ. The Ability to Dissipate Heat Is Likely to Be a More Important Limitation on Lactation in Striped Hamsters with Greater Reproductive Efforts under Warmer Conditions. Physiol Biochem Zool 2021; 93:282-295. [PMID: 32484722 DOI: 10.1086/709538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The limitations on energy availability and outputs have been implied to have a profound effect on the evolution of many morphological and behavioral traits. It has been suggested that the reproductive performance of mammals is frequently constrained by intrinsic physiological factors, such as the capacity of the mammary glands to produce milk (the peripheral limitation [PL] hypothesis) or that of the body to dissipate heat (the heat dissipation limitation [HDL] hypothesis). Research on a variety of small mammals, however, has so far failed to provide unequivocal support for one hypothesis over the other. We tested the PL and HDL hypotheses in female striped hamsters (Cricetulus barabensis) with artificially manipulated litter sizes of two (three or four pups removed from natural litter size), five, eight (two or three pups added to natural litter size), and 12 (five to seven pups added to natural litter size) pups at ambient temperatures of 21° and 30°C. Energy intake and milk output of mothers, litter size, and litter mass were measured throughout lactation. Several markers indicating digestive enzyme activity and the gene expression of hypothalamic neuropeptides related to food intake were also measured. Food consumption and milk output increased with increasing litter size but reached a ceiling at 12 pups, causing 12-pup litters to have significantly lower litter mass and pup body mass than litters composed of fewer pups. Litter mass and maternal metabolic rate, milk output, maltase, sucrase, and aminopeptidase activity in the small intestine, and gene expression of hypothalamic orexigenic peptides were significantly lower at 30°C than at 21°C, and these differences were considerably more pronounced in 12-pup litters. These results suggest that PL and HDL can operate simultaneously but that the HDL hypothesis is probably more valid at warmer temperatures. Our results suggest that increased environmental temperatures in future climates may limit reproductive output through heat dissipation limits.
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16
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Ohrnberger SA, Hambly C, Speakman JR, Valencak TG. Limits to sustained energy intake. XXXII. Hot again: dorsal shaving increases energy intake and milk output in golden hamsters ( Mesocricetus auratus). J Exp Biol 2020; 223:jeb230383. [PMID: 33188060 DOI: 10.1242/jeb.230383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022]
Abstract
Golden hamsters have four times the body size of mice, raise very large litters and are required to produce large quantities of milk during the 18-day lactation period. We have previously proposed that they may be prone to being limited by their heat dissipation capacity. Studies where lactating females are shaved to elevate their heat dissipation capacity have yielded conflicting data so far. With their short pregnancy of ∼18 days, the large litters and the reported high skin temperatures, they may serve as an ideal model to elucidate the role of epilation for energy budgets in lactating mammals. We shaved one group of lactating females dorsally on the sixth day of lactation, and tested if the elevated heat dissipation capacity would enable them to have higher energy intakes and better food-to-milk conversion rates. Indeed, we observed that females from the shaved group had 6% higher body mass and 0.78°C lower skin temperature than control females during lactation. When focusing on the phase of peak lactation, we observed significantly higher (10%) gross energy intake of food and 23.4% more milk energy output in the shaved females, resulting in 3.3 g higher individual pup weights. We conclude that shaving off the females' fur, even though restricted to the dorsal surface, had large consequences on female energy metabolism in lactation and improved milk production and pup growth in line with our previous work on heat dissipation limitation. Our new data from golden hamsters confirm heat dissipation as a limiting factor for sustained metabolic rate in lactation in some small mammals and emphasise the large effects of a relatively small manipulation such as fur removal on energy metabolism of lactating females.
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Affiliation(s)
- S A Ohrnberger
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
| | - C Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - J R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
- CAS Center of Excellence in Animal Evolution and Genetics, Kunming 650223, China
| | - T G Valencak
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
- College of Animal Sciences, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, 310058 Hangzhou, People's Republic of China
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17
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Xiao Y, Kronenfeld JM, Renquist BJ. Feed intake-dependent and -independent effects of heat stress on lactation and mammary gland development. J Dairy Sci 2020; 103:12003-12014. [PMID: 33041042 DOI: 10.3168/jds.2020-18675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 07/19/2020] [Indexed: 11/19/2022]
Abstract
With a growing population, a reliable food supply is increasingly important. Heat stress reduces livestock meat and milk production. Genetic selection of high-producing animals increases endogenous heat production, while climate change increases exogenous heat exposure. Both sources of heat exacerbate the risk of heat-induced depression of production. Rodents are valuable models to understand mechanisms conserved across species. Heat exposure suppresses feed intake across homeothermic species including rodents and production animal species. We assessed the response to early-mid lactation or late-gestation heat exposure on milk production and mammary gland development/function, respectively. Using pair-fed controls we experimentally isolated the feed intake-dependent and -independent effects of heat stress on mammary function and mass. Heat exposure (35°C, relative humidity 50%) decreased daily feed intake. When heat exposure occurred during lactation, hypophagia accounted for approximately 50% of the heat stress-induced hypogalactia. Heat exposure during middle to late gestation suppressed feed intake, which was fully responsible for the lowered mammary gland weight of dams at parturition. However, the impaired mammary gland function in heat-exposed dams measured by metabolic rate and lactogenesis could not be explained by depressed feed consumption. In conclusion, mice recapitulate the depressed milk production and mammary gland development observed in dairy species while providing insight regarding the role of feed intake. This opens the potential to apply genetic, experimental, and pharmacological models unique to mice to identify the mechanism by which heat is limiting animal production.
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Affiliation(s)
- Yao Xiao
- School of Animal and Comparative Biomedical Science, University of Arizona, Tucson 85721; Department of Animal Sciences, University of Florida, Gainesville 32611
| | - Jason M Kronenfeld
- School of Animal and Comparative Biomedical Science, University of Arizona, Tucson 85721
| | - Benjamin J Renquist
- School of Animal and Comparative Biomedical Science, University of Arizona, Tucson 85721.
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18
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Late lactation in small mammals is a critically sensitive window of vulnerability to elevated ambient temperature. Proc Natl Acad Sci U S A 2020; 117:24352-24358. [PMID: 32929014 DOI: 10.1073/pnas.2008974117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Predicted increases in global average temperature are physiologically trivial for most endotherms. However, heat waves will also increase in both frequency and severity, and these will be physiologically more important. Lactating small mammals are hypothesized to be limited by heat dissipation capacity, suggesting high temperatures may adversely impact lactation performance. We measured reproductive performance of mice and striped hamsters (Cricetulus barabensis), including milk energy output (MEO), at temperatures between 21 and 36 °C. In both species, there was a decline in MEO between 21 and 33 °C. In mice, milk production at 33 °C was only 18% of that at 21 °C. This led to reductions in pup growth by 20% but limited pup mortality (0.8%), because of a threefold increase in growth efficiency. In contrast, in hamsters, MEO at 33 °C was reduced to 78.1% of that at 21 °C, yet this led to significant pup mortality (possibly infanticide) and reduced pup growth by 12.7%. Hamster females were more able to sustain milk production as ambient temperature increased, but they and their pups were less capable of adjusting to the lower supply. In both species, exposure to 36 °C resulted in rapid catastrophic lactation failure and maternal mortality. Upper lethal temperature was lowered by 3 to 6 °C in late lactation, making it a critically sensitive window to high ambient temperatures. Our data suggest future heat wave events will impact breeding success of small rodents, but this is based on animals with a long history in captivity. More work should be performed on wild rodents to confirm these impacts.
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19
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Deng GM, Yu JX, Xu JQ, Bao YF, Chen Q, Cao J, Zhao ZJ. Exposure to artificial wind increases energy intake and reproductive performance of female Swiss mice ( Mus musculus) in hot temperatures. J Exp Biol 2020; 223:jeb231415. [PMID: 32665446 DOI: 10.1242/jeb.231415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/07/2020] [Indexed: 12/14/2022]
Abstract
High temperatures and heatwaves are rapidly emerging as an important threat to many aspects of physiology and behavior in females during lactation. The body's capacity to dissipate heat is reduced by high ambient temperatures, increasing the risk of hyperthermia. Exposure to wind, a pervasive environmental factor for most terrestrial animals, is known to increase heat loss, but its effects on the reproductive performance of small mammals remains unclear. In the present study, the effects of wind on the energy budgets, resting metabolic rate and milk energy output (MEO) were measured in lactating Swiss mice at 21 and 32.5°C. Females kept at 32.5°C had a significantly lower resting metabolic rate, food intake and MEO, and lighter offspring, than those kept at 21°C. However, exposure to wind increased the asymptotic food intake of females kept at 32.5°C by 22.5% (P<0.01), their MEO by 20.7% (P<0.05) and their litter mass by 17.6% (P<0.05). The body temperature of females kept at 32.5°C was significantly higher during lactation than that of females kept at 21°C, but this difference was reduced by exposure to wind. These findings suggest that exposure to wind considerably improves reproductive performance, increasing the fitness of small mammals while undergoing hot temperatures during heatwaves.
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Affiliation(s)
- Guang-Min Deng
- Department of Biology, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing-Xin Yu
- Department of Biology, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jia-Qi Xu
- Department of Biology, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Yu-Fan Bao
- Department of Biology, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Qian Chen
- Department of Biology, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- Department of Biology, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Zhi-Jun Zhao
- Department of Biology, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
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20
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Yu JX, Deng GM, Xu JQ, Cao J, Zhao ZJ. The energy budget and fat accumulation in striped hamsters (Cricetulus barabensis) during post-lactation. Comp Biochem Physiol A Mol Integr Physiol 2020; 249:110755. [PMID: 32673739 DOI: 10.1016/j.cbpa.2020.110755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/05/2020] [Accepted: 07/06/2020] [Indexed: 12/23/2022]
Abstract
Adaptive adjustments of energy intake and body fat play an important role in allowing animals' to meet the energy demands of thermoregulation during cold conditions and reproduction. Body fat is usually metabolized during lactation, which is one of the most energetically demanding activities of female mammals, however the effect of this on the energy budget and body fat regulation after lactation remains unclear. We compared the energy intake and body fat of female striped hamsters (Cricetulus barabensis) fed either a high-fat or low-fat diet for 21 days after the end of lactation (post-lactation, PL) to those of virgin controls. Serum leptin levels and the expression of hypothalamic orexigenic and anorexigenic neuropeptide genes were also measured and compared. Although lactating females consumed significantly more food, they had significantly lower body fat than virgin controls. The energy intake and body fat levels of the PL females were, however, significantly higher than those of virgin females. This was particularly true for the PL females that were fed high-fat diet. These females had significantly higher serum leptin concentrations, but lower hypothalamic leptin receptor gene expression, than virgin females. Neither orexigenic nor anorexigenic neuropeptide levels in the hypothalamus differed significantly between the PL and virgin females. This suggests that a negative energy balance during lactation drives fat accumulation after lactation. Furthermore, leptin resistance may occur after the end of lactation, causing females to consume more food, and accumulate more fat, than virgin females.
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Affiliation(s)
- Jing-Xin Yu
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Guang-Min Deng
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jia-Qi Xu
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China.
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21
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Huang Y, Mendoza JO, Hambly C, Li B, Jin Z, Li L, Madizi M, Hu S, Speakman JR. Limits to sustained energy intake. XXXI. Effect of graded levels of dietary fat on lactation performance in Swiss mice. J Exp Biol 2020; 223:jeb221911. [PMID: 32291324 DOI: 10.1242/jeb.221911] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 04/04/2020] [Indexed: 08/26/2023]
Abstract
The heat dissipation limit theory predicts that lactating female mice consuming diets with lower specific dynamic action (SDA) should have enhanced lactation performance. Dietary fat has lower SDA than other macronutrients. Here we tested the effects of graded dietary fat levels on lactating Swiss mice. We fed females five diets varying in fat content from 8.3 to 66.6%. Offspring of mothers fed diets of 41.7% fat and above were heavier and fatter at weaning compared with those of 8.3 and 25% fat diets. Mice on dietary fat contents of 41.7% and above had greater metabolizable energy intake at peak lactation (8.3%: 229.4±39.6; 25%: 278.8±25.8; 41.7%: 359.6±51.5; 58.3%: 353.7±43.6; 66.6%: 346±44.7 kJ day-1), lower daily energy expenditure (8.3%: 128.5±16; 25%: 131.6±8.4; 41.7%: 124.4±10.8; 58.3%: 115.1±10.5; 66.6%: 111.2±11.5 kJ day-1) and thus delivered more milk energy to their offspring (8.3%: 100.8±27.3; 25%: 147.2±25.1; 41.7%: 225.1±49.6; 58.3%: 238.6±40.1; 66.6%: 234.8±41.1 kJ day-1). Milk fat content (%) was unrelated to dietary fat content, indicating that females on higher fat diets (>41.7%) produced more rather than richer milk. Mothers consuming diets with 41.7% fat or above enhanced their lactation performance compared with those on 25% or less, probably by diverting dietary fat directly into the milk, thereby avoiding the costs of lipogenesis. At dietary fat contents above 41.7% they were either unable to transfer more dietary fat to the milk, or they chose not to do so, potentially because of a lack of benefit to the offspring that were increasingly fatter as maternal dietary fat increased.
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Affiliation(s)
- Yi Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | | | - Catherine Hambly
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Baoguo Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Zengguang Jin
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- School of Basic Medical Science, Dali University, Dali, Yunnan 671000, China
| | - Li Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Moshen Madizi
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Sumei Hu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - John R Speakman
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- CAS Center for Excellence in Animal Evolution and Genetics, Kunming, Yunnan 650223, China
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22
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Zhao ZJ, Derous D, Gerrard A, Wen J, Liu X, Tan S, Hambly C, Speakman JR. Limits to sustained energy intake. XXX. Constraint or restraint? Manipulations of food supply show peak food intake in lactation is constrained. J Exp Biol 2020; 223:jeb208314. [PMID: 32139473 DOI: 10.1242/jeb.208314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 02/27/2020] [Indexed: 11/20/2022]
Abstract
Lactating mice increase food intake 4- to 5-fold, reaching an asymptote in late lactation. A key question is whether this asymptote reflects a physiological constraint, or a maternal investment strategy (a 'restraint'). We exposed lactating mice to periods of food restriction, hypothesizing that if the limit reflected restraint, they would compensate by breaching the asymptote when refeeding. In contrast, if it was a constraint, they would by definition be unable to increase their intake on refeeding days. Using isotope methods, we found that during food restriction, the females shut down milk production, impacting offspring growth. During refeeding, food intake and milk production rose again, but not significantly above unrestricted controls. These data provide strong evidence that asymptotic intake in lactation reflects a physiological/physical constraint, rather than restraint. Because hypothalamic neuropeptide Y (Npy) was upregulated under both states of restriction, this suggests the constraint is not imposed by limits in the capacity to upregulate hunger signalling (the saturated neural capacity hypothesis). Understanding the genetic basis of the constraint will be a key future goal and will provide us additional information on the nature of the constraining factors on reproductive output, and their potential links to life history strategies.
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Affiliation(s)
- Zhi-Jun Zhao
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Davina Derous
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Abby Gerrard
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100100, China
| | - Jing Wen
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Xue Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100100, China
| | - Song Tan
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Catherine Hambly
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - John R Speakman
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100100, China
- CAS Center of Excellence for Animal Evolution and Genetics, Kunming 650223, China
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Preston DB, Johnson SG. Generalist grasshoppers from thermally variable sites do not have higher thermal tolerance than grasshoppers from thermally stable sites - A study of five populations. J Therm Biol 2020; 88:102527. [PMID: 32126002 DOI: 10.1016/j.jtherbio.2020.102527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 01/20/2020] [Accepted: 01/20/2020] [Indexed: 11/24/2022]
Abstract
Thermal tolerance allows many organisms, including insects, to withstand stressful temperatures. Thermal generalists are expected to have higher thermal tolerance than specialists, but the environmental conditions leading to the evolution of a thermal generalist life history are not fully understood. Thermal variability has been put forth as an evolutionary driver of high thermal tolerance, but rarely has this been empirically tested. We used a generalist agricultural pest grasshopper, Melanoplus differentialis, to test upper and lower thermal limits of populations that experienced different levels of thermal variability. We quantified thermal heterogeneity at five sites in a longitudinal transect in the Midwestern U.S. by examining, over a 101-year period, 1) variance in daily thermal maxima and minima; and 2) daily range. Also, as a measure of a biologically relevant thermal extreme, we depicted days per month at each site that reached a stressfully high temperature for M. differentialis. We collected individuals from these sites and tested their upper and lower thermal limits. We found that most of our metrics of thermal heterogeneity differed among sites, while all sites experienced an average of at least two stressfully high temperature events per month. We found that heavier males from these sites were able to withstand both warmer and colder temperatures than smaller males, while heavier females had no thermal advantage over lighter females. However, site of origin had no effect on thermal tolerance. Our findings indicate three things: 1) there is no clear correlation between thermal variability and thermal tolerance in the populations we studied; 2) weight affects thermal tolerance range among sites for M. differentialis males, and 3) thermal extremes may be more important than thermal variability in determining CTMax in this species.
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Affiliation(s)
- Devin B Preston
- Department of Biological Sciences, University of New Orleans, New Orleans, LA, USA.
| | - Steven G Johnson
- Department of Biological Sciences, University of New Orleans, New Orleans, LA, USA.
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Bao MH, Chen LB, Hambly C, Speakman JR, Zhao ZJ. Exposure to hot temperatures during lactation stunted offspring growth and decreased the future reproductive performance of female offspring. J Exp Biol 2020:jeb.223560. [PMID: 34005557 DOI: 10.1242/jeb.223560] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 03/31/2020] [Indexed: 12/15/2022]
Abstract
Among the important aspects of climate change, exposure to high temperatures (heat waves) is rapidly emerging as an important issue, in particular for female mammals during lactation. High temperatures adversely impact ability to dissipate heat, which has negative effects on reproductive output. The cumulative effects on growth of F1 offspring after weaning and future reproductive performance of offspring remain uncertain. In this study, the F1 mice that weaned from mothers lactating at 21°C and 32.5°C were housed at 21°C from day 19 till 56 of age; during which food intake and body mass were measured. The F1 adult females that had been weaned at the two temperatures were bred and then both exposed to 32.5°C during lactation. Energy intake, milk output and litter size and mass were determined. The F1 adults weaned at 32.5°C consumed less food and had lower body mass than their counterparts weaned at 21°C. Several visceral organs or reproductive tissues were significantly lower in mass in F1 weaned at 32.5°C than at 21°C. The exposure to 32.5°C significantly decreased energy intake, milk output and litter mass in F1 adult females during lactation. The F1 adult females weaned at 32.5°C produced less milk and raised lighter pups than those previously weaned at 21°C. The data suggest that transient exposure to hot temperature during lactation has long-lasting impacts on the offspring, including stunted growth and decreases in future reproductive performance when adult. This indicates that the offspring of females previously experiencing hot temperatures have a significant fitness disadvantage.
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Affiliation(s)
- Meng-Huan Bao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Li-Bing Chen
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Catherine Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Bei Chen Xi Lu, Chaoyang, Beijing 100101, People's Republic of China
- CAS Center of Excellence in Animal Evolution and Genetics, Kunming, People's Republic of China
| | - Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
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Andreasson F, Hegemann A, Nord A, Nilsson JÅ. Experimental facilitation of heat loss affects work rate and innate immune function in a breeding passerine bird. J Exp Biol 2020; 223:jeb.219790. [DOI: 10.1242/jeb.219790] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/11/2020] [Indexed: 01/06/2023]
Abstract
The capacity to get rid of excess heat produced during hard work is a possible constraint on parental effort during reproduction (heat dissipation limit [HDL] theory). We released hard-working blue tits (Cyanistes caeruleus) from this constraint by experimentally removing ventral plumage. We then assessed if this changed their reproductive effort (feeding rate and nestling size) and levels of self-maintenance (change in body mass and innate immune function). Feather-clipped females reduced the number of feeding visits and increased levels of constitutive innate immunity compared to unclipped females but did not fledge smaller nestlings. Thus, they increased self-maintenance without compromising current reproductive output. In contrast, feather-clipping did not affect the number of feeding visits or innate immune function in males, despite increased heat loss rate. Our results show that analyses of physiological parameters, such as constitutive innate immune function, can be important when trying to understand sources of variation in investment in self-maintenance versus reproductive effort and that risk of overheating can influence innate immune function during reproduction.
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Affiliation(s)
- Fredrik Andreasson
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Arne Hegemann
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Andreas Nord
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Rowardennan G63 0AW, UK
| | - Jan-Åke Nilsson
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
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26
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Switching off the furnace: brown adipose tissue and lactation. Mol Aspects Med 2019; 68:18-41. [DOI: 10.1016/j.mam.2019.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/12/2019] [Indexed: 12/31/2022]
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Affiliation(s)
- Andreas Nord
- Department of Biology, Section for Evolutionary Ecology, Ecology Building Lund University Lund Sweden
| | - Jan‐Åke Nilsson
- Department of Biology, Section for Evolutionary Ecology, Ecology Building Lund University Lund Sweden
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28
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Vaanholt LM, Duah OA, Balduci S, Mitchell SE, Hambly C, Speakman JR. Limits to sustained energy intake. XXVII. Trade-offs between first and second litters in lactating mice support the ecological context hypothesis. ACTA ACUST UNITED AC 2018; 221:jeb.170902. [PMID: 29361590 DOI: 10.1242/jeb.170902] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/27/2017] [Indexed: 12/18/2022]
Abstract
Increased reproductive effort may lead to trade-offs with future performance and impact offspring, thereby influencing optimal current effort level. We experimentally enlarged or reduced litter size in mice during their first lactation, and then followed them through a successive unmanipulated lactation. Measurements of food intake, body mass, milk energy output (MEO), litter size and litter mass were taken. Offspring from the first lactation were also bred to investigate their reproductive success. In their first lactation, mothers with enlarged litters (n=9, 16 pups) weaned significantly smaller pups, culled more pups, and increased MEO and food intake compared with mothers with reduced litters (n=9, 5 pups). In the second lactation, no significant differences in pup mass or litter size were observed between groups, but mothers that had previously reared enlarged litters significantly decreased pup mass, MEO and food intake compared with those that had reared reduced litters. Female offspring from enlarged litters weaned slightly smaller pups than those from reduced litters, but displayed no significant differences in any of the other variables measured. These results suggest that females with enlarged litters suffered from a greater energetic burden during their first lactation, and this was associated with lowered performance in a successive reproductive event and impacted on their offspring's reproductive performance. Female 'choice' about how much to invest in the first lactation may thus be driven by trade-offs with future reproductive success. Hence, the 'limit' on performance may not be a hard physiological limit. These data support the ecological context hypothesis.
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Affiliation(s)
- Lobke M Vaanholt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Osei A Duah
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Suzanna Balduci
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Sharon E Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Catherine Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK .,Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beijing, People's Republic of China
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Ohrnberger SA, Hambly C, Speakman JR, Valencak TG. Limits to sustained energy intake XXIX: the case of the golden hamster (Mesocricetus auratus). J Exp Biol 2018; 221:jeb.183749. [DOI: 10.1242/jeb.183749] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/11/2018] [Indexed: 01/11/2023]
Abstract
Golden hamster females have the shortest known gestation period among placental mammals and at the same time raise very large litters of up to 16 offspring, which are born in a naked and blind state and are able to pick up food from days 12-14 only. We quantified energy metabolism and milk production in female golden hamsters raising offspring under cold (8°C), normal (22°C) and hot (30°C) ambient temperature conditions. We monitored energy intake, subcutaneous body temperature, daily energy expenditure, litter size and pup masses over the course of lactation. Our results show that, in line with the concept of heat dissipation limitation, female golden hamsters had the largest energy intake under the coldest conditions and a significantly lower intake at 30° (partial for influence of ambient temperature: F2,403=5.6; p= 0.004). Metabolisable energy intake as well as milk energy output showed the same pattern and were significantly different between the temperatures (partial for milk energy production: F1,40= 86.4; p<0.0001). With consistently higher subcutaneous temperatures in the reproductive females (F1,813= 36.77; p<0.0001) compared to baseline females. These data suggest that raising offspring in golden hamsters comes at the cost of producing large amounts of body heat up to a level constraining energy intake, similar to that observed in some laboratory mice. Notably, we observed that females seemed to adjust litter size according to their milk production with the smallest litters (3.4±0.7 pups) being raised by hot exposed mothers. Future research is needed to unravel the mechanism by which females assess their own milk production capabilities and how this may be linked to litter size at different ambient temperatures. Golden hamsters reach 8-10 times resting metabolic rate (RMR) when raising offspring under cold conditions, which is compatible with the findings from laboratory mice and other rodents.
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Affiliation(s)
- S. A. Ohrnberger
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
| | - C. Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB 24 2 TZ, UK
| | - J. R. Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB 24 2 TZ, UK
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beichen Xi Lu, Chaoyang, Beijing, People's Republic of China
| | - T. G. Valencak
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
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Kagya-Agyemang JK, Vaanholt LM, Hambly C, Król E, Mitchell SE, Speakman JR. Limits to sustained energy intake XXVIII: Beneficial effects of high dietary fat on lactation performance in mice. J Exp Biol 2018; 221:jeb.180828. [DOI: 10.1242/jeb.180828] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/20/2018] [Indexed: 12/22/2022]
Abstract
Maximal animal performance may be limited by the ability of animals to dissipate heat; the heat dissipation limitation (HDL) theory. Since diets vary in the incidental heat produced during digestion (specific dynamic action, SDA), the HDL theory predicts lactating female mice consuming diets with lower SDA should have increased reproductive performance. Dietary fat has a lower SDA than dietary carbohydrate. Female mice were fed low (LF), medium (MF) or high fat (HF) diets (10%, 45% and 60% energy from fat respectively) from days 4-18 of lactation. HF and MF-fed mice weaned significantly heavier litters than LF mice. This was because they not only consumed more energy (metabolisable energy intake, Emei; HF:306.5±25.0, MF:340.5±13.5 kJ d−1) at peak lactation, but also delivered more milk energy to their pups (milk energy output, Emilk: 203.2±49.9, 229.3±42.2 kJ d−1 respectively) than the LF-fed mice (Emei =266.7±4.5, Emilk =164.60±30.59 kJ d−1). This effect was greater than predicted from the SDA of the different diets combined with a mathematical model based on the HDL theory. Fatty acid profiles of the diets, milk and pups, showed significant correlations between the profiles. Besides reduced SDA, HF and MF-fed mice were probably able to directly transfer absorbed dietary fat into milk, reducing the heat production of lactogenesis, and enabling them to perform better than expected from the HDL model. In summary, HF and MF diets had beneficial effects on reproductive performance compared to the LF diet because they enabled mice to generate milk more efficiently with less incidental heat production.
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Affiliation(s)
- J. K. Kagya-Agyemang
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- College of Agriculture Education, University of Education, Winneba, P.O. Box 40, Mampong-Ashanti, Ghana
| | - L. M. Vaanholt
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - C. Hambly
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - E. Król
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - S. E. Mitchell
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - J. R. Speakman
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- State key laboratory of molecular developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing China
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Sassi PL, Menéndez J, Cuevas MF. Geographic variation in life-history traits: factors shaping energy investment in reproduction in a highland dwelling rodent. J Zool (1987) 2017. [DOI: 10.1111/jzo.12523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. L. Sassi
- CCT-Mendoza CONICET; Grupo de Investigaciones de la Biodiversidad; CONICET; Instituto Argentino de Investigaciones de Zonas Áridas; Mendoza Argentina
- Facultad de Ciencias Exactas y Naturales; Universidad Nacional de Cuyo; Mendoza Argentina
| | - J. Menéndez
- Facultad de Ciencias Exactas y Naturales; Universidad Nacional de Cuyo; Mendoza Argentina
| | - M. F. Cuevas
- CCT-Mendoza CONICET; Grupo de Investigaciones de la Biodiversidad; CONICET; Instituto Argentino de Investigaciones de Zonas Áridas; Mendoza Argentina
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32
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Shelton DS, Alberts JR. Development of behavioral responses to thermal challenges. Dev Psychobiol 2017; 60:5-14. [PMID: 29152730 DOI: 10.1002/dev.21588] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 09/04/2017] [Indexed: 12/14/2022]
Abstract
Body temperature regulation involves the development of responses to cold and warm challenges. Matching our understanding of the development of body temperature regulation to warm challenges with that of cold challenges will enhance our understanding of the ontogeny of thermoregulation and reveal different adaptive specializations. Warm and cold thermoregulation are important processes, and they include direct thermal effects on offspring, as well as indirect effects on them, such as those imposed by thermally associated alterations of maternal behavior. The present paper is a selective review of the existing literature and a report of some new empirical data, aimed at processes of mammalian development, especially those affecting behavior. We briefly discuss the development of body temperature regulation in rats and mice, and thermal aspects of maternal behavior with emphasis on responses to high temperatures. The new data extend previous analyses of individual and group responses in developing rodents to warm and cool ambient temperatures. This literature not only reveals a variety of adaptive specializations during development, but it points to the earlier appearance in young mammals of abilities to combat heat loss, relative to protections from hyperthermia. These relative developmental delays in compensatory defenses to heating appear to render young mammals especially vulnerable to environmental warming. We describe cascading consequences of warming-effects that illustrate interactions across levels of physiological, neural, and behavioral development.
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Affiliation(s)
- Delia S Shelton
- Leibniz Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany.,Oregon State University, Corvallis, Oregon.,University of Windsor, Windsor, Ontario
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Wen J, Tan S, Qiao QG, Fan WJ, Huang YX, Cao J, Liu JS, Wang ZX, Zhao ZJ. Sustained energy intake in lactating Swiss mice: a dual modulation process. J Exp Biol 2017; 220:2277-2286. [DOI: 10.1242/jeb.157107] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/04/2017] [Indexed: 12/15/2022]
Abstract
Limits to sustained energy intake (SusEI) during lactation are important because they provide an upper boundary below which females must trade-off competing physiological activities. To date, SusEI is thought to be limited either by the capacity of the mammary glands to produce milk (the peripheral limitation hypothesis), or by a female's ability to dissipate body heat (the heat dissipation hypothesis). In the present study, we examined the effects of litter size and ambient temperature on a set of physiological, behavioral, and morphological indicators of SusEI and reproductive performance in lactating Swiss mice. Our results indicate that energy input, output, and mammary gland mass increased with litter size, whereas pup body mass and survival rate decreased. The body temperature increased significantly, while food intake (18g/d at 21°C vs 10g/d at 30°C), thermal conductance (lower by 20-27% at 30°C than 21°C), litter mass and MEO decreased significantly in the females raising large litter size at 30°C compared to those at 21°C. Furthermore, an interaction between ambient temperature and litter size affected females' energy budget, imposing strong constraints on SusEI. Together, out data suggest that the limitation may be caused by both mammary glands and heat dissipation, i.e. the limits to mammary gland is dominant at the room temperature, but heat limitation is more significant at warm temperatures. Further, the level of heat dissipation limits may be temperature dependent, shifting down with increasing temperature.
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Affiliation(s)
- Jing Wen
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Song Tan
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Qing-Gang Qiao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Wei-Jia Fan
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Yi-Xin Huang
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jin-Song Liu
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Zuo-Xin Wang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306-1270, USA
| | - Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
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Ohrnberger SA, Monclús R, Rödel HG, Valencak TG. Ambient temperature affects postnatal litter size reduction in golden hamsters. Front Zool 2016; 13:51. [PMID: 27904644 PMCID: PMC5121935 DOI: 10.1186/s12983-016-0183-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 11/15/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To better understand how different ambient temperatures during lactation affect survival of young, we studied patterns of losses of pups in golden hamsters (Mesocricetus auratus) at different ambient temperatures in the laboratory, mimicking temperature conditions in natural habitats. Golden hamsters produce large litters of more than 10 young but are also known to wean fewer pups at the end of lactation than they give birth to. We wanted to know whether temperature affects litter size reductions and whether the underlying causes of pup loss were related to maternal food (gross energy) intake and reproductive performance, such as litter growth. For that, we exposed lactating females to three different ambient temperatures and investigated associations with losses of offspring between birth and weaning. RESULTS Overall, around one third of pups per litter disappeared, obviously consumed by the mother. Such litter size reductions were greatest at 30 °C, in particular during the intermediate postnatal period around peak lactation. Furthermore, litter size reductions were generally higher in larger litters. Maternal gross energy intake was highest at 5 °C suggesting that mothers were not limited by milk production and might have been able to raise a higher number of pups until weaning. This was further supported by the fact that the daily increases in litter mass as well as in the individual pup body masses, a proxy of mother's lactational performance, were lower at higher ambient temperatures. CONCLUSIONS We suggest that ambient temperatures around the thermoneutral zone and beyond are preventing golden hamster females from producing milk at sufficient rates. Around two thirds of the pups per litter disappeared at high temperature conditions, and their early growth rates were significantly lower than at lower ambient temperatures. It is possible that these losses are due to an intrinsic physiological limitation (imposed by heat dissipation) compromising maternal energy intake and milk production.
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Affiliation(s)
- Sarah A. Ohrnberger
- Institute of Physiology, Pathophysiology and Biophysics, Veterinary University Vienna, Vienna, Austria
| | - Raquel Monclús
- Ecologie Systématique Evolution, University Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, F-91400 Orsay, France
| | - Heiko G. Rödel
- Laboratoire d’Ethologie Expérimentale et Comparée E.A. 4443, Université Paris 13, Sorbonne Paris Cité, F-93430 Villetaneuse, France
| | - Teresa G. Valencak
- Institute of Physiology, Pathophysiology and Biophysics, Veterinary University Vienna, Vienna, Austria
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Zhao ZJ, Li L, Yang DB, Chi QS, Hambly C, Speakman JR. Limits to sustained energy intake XXV: milk energy output and thermogenesis in Swiss mice lactating at thermoneutrality. Sci Rep 2016; 6:31626. [PMID: 27554919 PMCID: PMC4995430 DOI: 10.1038/srep31626] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 07/22/2016] [Indexed: 01/13/2023] Open
Abstract
Previous studies at 21 °C and 5 °C suggest that in Swiss mice sustained energy intake (SusEI) and reproductive performance are constrained by the mammary capacity to produce milk. We aimed to establish if this constraint also applied at higher ambient temperature (30 °C). Female Swiss mice lactating at 30 °C had lower asymptotic food intake and weaned lighter litters than those at 21 °C. Resting metabolic rate, daily energy expenditure, milk energy output and suckling time were all lower at 30 °C. In a second experiment we gave mice at 30 °C either 6 or 9 pups to raise. Female performance was independent of litter size, indicating that it is probably not controlled by pup demands. In a third experiment we exposed only the mother, or only the offspring to the elevated temperature. In this case the performance of the mother was only reduced when she was exposed, and not when her pups were exposed, showing that the high temperature directly constrains female performance. These data suggest that at 30 °C SusEI and reproductive performance are likely constrained by the capacity of females to dissipate body heat, and not indirectly via pup demands. Constraints seem to change with ambient temperature in this strain of mouse.
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Affiliation(s)
- Zhi-Jun Zhao
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325027, China
| | - Li Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100100, China
| | - Deng-Bao Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100100, China
- State Key Laboratory of Integrated Management for Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China
| | - Qing-Sheng Chi
- State Key Laboratory of Integrated Management for Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China
| | - Catherine Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - John R. Speakman
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100100, China
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
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36
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Nater CR, Canale CI, van Benthem KJ, Yuen CH, Schoepf I, Pillay N, Ozgul A, Schradin C. Interactive effects of exogenous and endogenous factors on demographic rates of an African rodent. OIKOS 2016. [DOI: 10.1111/oik.03384] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chloé R. Nater
- Dept of Evolutionary Biology and Environmental Studies; Univ. of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
- Centre for Ecological and Evolutionary Synthesis (CEES), Dept of Biosciences; Univ. of Oslo; Blindern Oslo Norway
| | - Cindy I. Canale
- Dept of Evolutionary Biology and Environmental Studies; Univ. of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Koen J. van Benthem
- Dept of Evolutionary Biology and Environmental Studies; Univ. of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Chi-Hang Yuen
- School of Animal, Plant and Environmental Sciences; Univ. of the Witwatersrand; Braamfontein Johannesburg South Africa
| | - Ivana Schoepf
- School of Animal, Plant and Environmental Sciences; Univ. of the Witwatersrand; Braamfontein Johannesburg South Africa
| | - Neville Pillay
- School of Animal, Plant and Environmental Sciences; Univ. of the Witwatersrand; Braamfontein Johannesburg South Africa
| | - Arpat Ozgul
- Dept of Evolutionary Biology and Environmental Studies; Univ. of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Carsten Schradin
- School of Animal, Plant and Environmental Sciences; Univ. of the Witwatersrand; Braamfontein Johannesburg South Africa
- Inst. Pluridisciplinaire Hubert Curien; Dépt d'Ecologie Physiologie et Ethologie; Strasbourg France
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Książek A, Konarzewski M. Heat dissipation does not suppress an immune response in laboratory mice divergently selected for basal metabolic rate (BMR). ACTA ACUST UNITED AC 2016; 219:1542-51. [PMID: 26944492 DOI: 10.1242/jeb.129312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 03/01/2016] [Indexed: 01/01/2023]
Abstract
The capacity for heat dissipation is considered to be one of the most important constraints on rates of energy expenditure in mammals. To date, the significance of this constraint has been tested exclusively under peak metabolic demands, such as during lactation. Here, we used a different set of metabolic stressors, which do not induce maximum energy expenditures and yet are likely to expose the potential constraining effect of heat dissipation. We compared the physiological responses of mice divergently selected for high (H-BMR) and low basal metabolic rate (L-BMR) to simultaneous exposure to the keyhole limpet haemocyanin (KLH) antigen and high ambient temperature (Ta). At 34°C (and at 23°C, used as a control), KLH challenge resulted in a transient increase in core body temperature (Tb) in mice of both line types (by approximately 0.4°C). Warm exposure did not produce line-type-dependent differences in Tb (which was consistently higher by ca. 0.6°C in H-BMR mice across both Ta values), nor did it result in the suppression of antibody synthesis. These findings were also supported by the lack of between-line-type differences in the mass of the thymus, spleen or lymph nodes. Warm exposure induced the downsizing of heat-generating internal organs (small intestine, liver and kidneys) and an increase in intrascapular brown adipose tissue mass. However, these changes were similar in scope in both line types. Mounting a humoral immune response in selected mice was therefore not affected by ambient temperature. Thus, a combined metabolic challenge of high Ta and an immune response did not appreciably compromise the capacity to dissipate heat, even in the H-BMR mice.
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Affiliation(s)
- Aneta Książek
- Institute of Biology, University of Białystok, Ciołkowskiego 1J, Białystok 15-245, Poland
| | - Marek Konarzewski
- Institute of Biology, University of Białystok, Ciołkowskiego 1J, Białystok 15-245, Poland
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Sadowska ET, Król E, Chrzascik KM, Rudolf AM, Speakman JR, Koteja P. Limits to sustained energy intake. XXIII. Does heat dissipation capacity limit the energy budget of lactating bank voles? ACTA ACUST UNITED AC 2016; 219:805-15. [PMID: 26747907 DOI: 10.1242/jeb.134437] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/28/2015] [Indexed: 01/13/2023]
Abstract
Understanding factors limiting sustained metabolic rate (SusMR) is a central issue in ecological physiology. According to the heat dissipation limit (HDL) theory, the SusMR at peak lactation is constrained by the maternal capacity to dissipate body heat. To test that theory, we shaved lactating bank voles (Myodes glareolus) to experimentally elevate their capacity for heat dissipation. The voles were sampled from lines selected for high aerobic exercise metabolism (A; characterized also by increased basal metabolic rate) and unselected control lines (C). Fur removal significantly increased the peak-lactation food intake (mass-adjusted least square means ± s.e.; shaved: 16.3 ± 0.3 g day(-1), unshaved: 14.4 ± 0.2 g day(-1); P<0.0001), average daily metabolic rate (shaved: 109 ± 2 kJ day(-1), unshaved: 97 ± 2 kJ day(-1); P<0.0001) and metabolisable energy intake (shaved: 215 ± 4 kJ day(-1), unshaved: 185 ± 4 kJ day(-1); P<0.0001), as well as the milk energy output (shaved: 104 ± 4 kJ day(-1); unshaved: 93 ± 4 kJ day(-1); P=0.021) and litter growth rate (shaved: 9.4 ± 0.7 g 4 days(-1), unshaved: 7.7 ± 0.7 g 4 days(-1); P=0.028). Thus, fur removal increased both the total energy budget and reproductive output at the most demanding period of lactation, which supports the HDL theory. However, digestive efficiency was lower in shaved voles (76.0 ± 0.3%) than in unshaved ones (78.5 ± 0.2%; P<0.0001), which may indicate that a limit imposed by the capacity of the alimentary system was also approached. Shaving similarly affected the metabolic and reproductive traits in voles from the A and C lines. Thus, the experimental evolution model did not reveal a difference in the limiting mechanism between animals with inherently different metabolic rates.
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Affiliation(s)
- Edyta T Sadowska
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
| | - Elżbieta Król
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Katarzyna M Chrzascik
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
| | - Agata M Rudolf
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beichen Xi Lu, Chaoyang, Beijing 100101, People's Republic of China
| | - Paweł Koteja
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
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Zhang JY, Zhao XY, Wen J, Tan S, Zhao ZJ. Plasticity in gastrointestinal morphology and enzyme activity in lactating striped hamsters (Cricetulus barabensis). J Exp Biol 2016; 219:1327-36. [DOI: 10.1242/jeb.138396] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 02/19/2016] [Indexed: 11/20/2022]
Abstract
In small mammals marked phenotypic plasticity of digestive physiology has been shown to make it easier to cope with the energetically stressful periods, such as lactation. It has been proposed that the capacity of the gut to digest and absorb food is not the factor limiting to sustained energy intake (SusEI) during peak lactation. In this study, plasticity in energy intake and gastrointestinal morphology was examined in striped hamsters at different stages of reproduction and raising litters of different sizes. Mechanisms associated with digestive enzymes and neuroendocrine hormones underpinning the plasticity were also examined. The females significantly increased energy intake, digestibility, masses of digestive tracts and activity of stomach pepsin and maltase, sucrase and aminopeptidase of small intestine in peak lactation compared to the non-productive and post-lactating periods. Further, the females raising large litters significantly increased energy intake, digestibility, gastrointestinal mass and activity of digestive enzymes, and weaned heavier offspring compared with those nursing small and medium litters, indicating that the significant plasticity of digestive physiology increased reproductive performance. The agouti-related protein (AgRP) mRNA expression in the hypothalamus was up-regulated significantly in the females raising large litters relative to those raising small litters. Serum leptin levels, hypothalamus neuropeptide Y (NPY), or anorexigenic neuropeptides (pro-opiomelanocortin / cocaine- and amphetamine-regulated transcript, POMC / CART) mRNA expression did not differ among the females raising small, medium and large litters, indicating that leptin levels in lactation might only reflect a state of energy balance rather than being the prime driver of hyperphagia. Some hypothalamic neuropeptides, such as NPY, POMC and CART, would be involved in the limits to the SusEI during lactation.
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Affiliation(s)
- Ji-Ying Zhang
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Xiao-Ya Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing Wen
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Song Tan
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
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40
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Vaanholt LM, Milne A, Zheng Y, Hambly C, Mitchell SE, Valencak TG, Allison DB, Speakman JR. Oxidative costs of reproduction: Oxidative stress in mice fed standard and low antioxidant diets. Physiol Behav 2015; 154:1-7. [PMID: 26569452 DOI: 10.1016/j.physbeh.2015.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 10/29/2015] [Accepted: 11/09/2015] [Indexed: 01/18/2023]
Abstract
Lactation is one of the most energetically expensive behaviours, and trade-offs may exist between the energy devoted to it and somatic maintenance, including protection against oxidative damage. However, conflicting data exist for the effects of reproduction on oxidative stress. In the wild, a positive relationship is often observed, but in laboratory studies oxidative damage is often lower in lactating than in non-breeding animals. We hypothesised that this discrepancy may exist because during lactation food intake increases many-fold resulting in a large increase in the intake of dietary antioxidants which are typically high in laboratory rodent chow where they are added as a preservative. We supplied lactating and non-breeding control mice with either a standard or low antioxidant diet and studied how this affected the activity of endogenous antioxidants (catalase, superoxide dismutase; SOD, and glutathione peroxidise; GPx) and oxidative damage to proteins (protein carbonyls, PC) in liver and brain tissue. The low antioxidant diet did not significantly affect activities of antioxidant enzymes in brain or liver, and generally did not result in increased protein damage, except in livers of control mice on low antioxidant diet. Catalase activity, but not GPx or SOD, was decreased in both control and lactating mice on the low antioxidant diet. Lactating mice had significantly reduced oxidative damage to both liver and brain compared to control mice, independent of the diet they were given. In conclusion, antioxidant content of the diet did not affect oxidative stress in control or reproductive mice, and cannot explain the previously observed reduction in oxidative stress in lactating mammals studied in the laboratory. The reduced oxidative stress in the livers of lactating mice even under low antioxidant diet treatment was consistent with the 'shielding' hypothesis.
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Affiliation(s)
- L M Vaanholt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - A Milne
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - Y Zheng
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - C Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - S E Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - T G Valencak
- University of Veterinary Medicine in Vienna, Department of Integrative Biology and Evolution, Vienna, Austria
| | - D B Allison
- Nutrition Obesity Research Center, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - J R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
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41
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Sassi PL, Taraborelli P, Albanese S, Gutierrez A. Effect of Temperature on Activity Patterns in a Small Andean Rodent: Behavioral Plasticity and Intraspecific Variation. Ethology 2015. [DOI: 10.1111/eth.12398] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paola L. Sassi
- Grupo de Investigaciones de la Biodiversidad; CONICET; Instituto Argentino de Investigaciones de las Zonas Áridas; CCT; Mendoza Argentina
| | - Paula Taraborelli
- Grupo de Investigaciones de la Biodiversidad; CONICET; Instituto Argentino de Investigaciones de las Zonas Áridas; CCT; Mendoza Argentina
| | - Soledad Albanese
- Grupo de Investigaciones de la Biodiversidad; CONICET; Instituto Argentino de Investigaciones de las Zonas Áridas; CCT; Mendoza Argentina
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42
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Rezende EL, Bacigalupe LD. Thermoregulation in endotherms: physiological principles and ecological consequences. J Comp Physiol B 2015; 185:709-27. [PMID: 26025431 DOI: 10.1007/s00360-015-0909-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 04/18/2015] [Accepted: 04/27/2015] [Indexed: 01/01/2023]
Abstract
In a seminal study published nearly 70 years ago, Scholander et al. (Biol Bull 99:259-271, 1950) employed Newton's law of cooling to describe how metabolic rates (MR) in birds and mammals vary predictably with ambient temperature (T a). Here, we explore the theoretical consequences of Newton's law of cooling and show that a thermoregulatory polygon provides an intuitively simple and yet useful description of thermoregulatory responses in endothermic organisms. This polygon encapsulates the region in which heat production and dissipation are in equilibrium and, therefore, the range of conditions in which thermoregulation is possible. Whereas the typical U-shaped curve describes the relationship between T a and MR at rest, thermoregulatory polygons expand this framework to incorporate the impact of activity, other behaviors and environmental conditions on thermoregulation and energy balance. We discuss how this framework can be employed to study the limits to effective thermoregulation and their ecological repercussions, allometric effects and residual variation in MR and thermal insulation, and how thermoregulatory requirements might constrain locomotor or reproductive performance (as proposed, for instance, by the heat dissipation limit theory). In many systems the limited empirical knowledge on how organismal traits may respond to environmental changes prevents physiological ecology from becoming a fully developed predictive science. In endotherms, however, we contend that the lack of theoretical developments that translate current physiological understanding into formal mechanistic models remains the main impediment to study the ecological and evolutionary repercussions of thermoregulation. In spite of the inherent limitations of Newton's law of cooling as an oversimplified description of the mechanics of heat transfer, we argue that understanding how systems that obey this approximation work can be enlightening on conceptual grounds and relevant as an analytical and predictive tool to study ecological phenomena. As such, the proposed approach may constitute a powerful tool to study the impact of thermoregulatory constraints on variables related to fitness, such as survival and reproductive output, and help elucidating how species will be affected by ongoing climate change.
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Affiliation(s)
- Enrico L Rezende
- Department of Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, UK.
| | - Leonardo D Bacigalupe
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile.
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Winney I, Nakagawa S, Hsu Y, Burke T, Schroeder J. Troubleshooting the potential pitfalls of cross‐fostering. Methods Ecol Evol 2015. [DOI: 10.1111/2041-210x.12341] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Isabel Winney
- Department of Animal and Plant Sciences University of Sheffield Sheffield S10 2TN UK
| | - Shinichi Nakagawa
- Department of Animal and Plant Sciences University of Sheffield Sheffield S10 2TN UK
- Department of Zoology University of Otago Dunedin New Zealand
| | - Yu‐Hsun Hsu
- Department of Zoology University of Otago Dunedin New Zealand
| | - Terry Burke
- Department of Animal and Plant Sciences University of Sheffield Sheffield S10 2TN UK
| | - Julia Schroeder
- Evolutionary Biology Max Planck Institute for Ornithology Seewiesen Germany
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44
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White CR, Kearney MR. Metabolic scaling in animals: methods, empirical results, and theoretical explanations. Compr Physiol 2014; 4:231-56. [PMID: 24692144 DOI: 10.1002/cphy.c110049] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Life on earth spans a size range of around 21 orders of magnitude across species and can span a range of more than 6 orders of magnitude within species of animal. The effect of size on physiology is, therefore, enormous and is typically expressed by how physiological phenomena scale with mass(b). When b ≠ 1 a trait does not vary in direct proportion to mass and is said to scale allometrically. The study of allometric scaling goes back to at least the time of Galileo Galilei, and published scaling relationships are now available for hundreds of traits. Here, the methods of scaling analysis are reviewed, using examples for a range of traits with an emphasis on those related to metabolism in animals. Where necessary, new relationships have been generated from published data using modern phylogenetically informed techniques. During recent decades one of the most controversial scaling relationships has been that between metabolic rate and body mass and a number of explanations have been proposed for the scaling of this trait. Examples of these mechanistic explanations for metabolic scaling are reviewed, and suggestions made for comparing between them. Finally, the conceptual links between metabolic scaling and ecological patterns are examined, emphasizing the distinction between (1) the hypothesis that size- and temperature-dependent variation among species and individuals in metabolic rate influences ecological processes at levels of organization from individuals to the biosphere and (2) mechanistic explanations for metabolic rate that may explain the size- and temperature-dependence of this trait.
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Affiliation(s)
- Craig R White
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia
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45
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Pinot A, Gauffre B, Bretagnolle V. The interplay between seasonality and density: consequences for female breeding decisions in a small cyclic herbivore. BMC Ecol 2014; 14:17. [PMID: 24886481 PMCID: PMC4049426 DOI: 10.1186/1472-6785-14-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/22/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cyclic rodent population dynamics are subjected to both intrinsic regulatory processes such as density-dependence and extrinsic environmental forcing. Among extrinsic factors, seasonal environmental variation is understood to facilitate cycles. In rodents, these processes have been studied mostly independently and their relative importance for population dynamics is poorly known. RESULTS We performed a detailed analysis of common vole (Microtus arvalis) reproduction in a cyclic population using a spatially extensive data set over 17 years in central-western France. Environmental seasonality was the main source of explained variation in common vole reproduction. Additionally, inter-annual variation in the environment explained a smaller part of the variance in reproduction in spring and summer than in winter, whereas the effect of density was only found in autumn and winter. In particular, we detected a strong impact of plant productivity on fecundity during the breeding season, with low vegetation productivity being able to bring vole reproduction nearly to a halt. In contrast, vole reproduction during autumn and winter was mainly shaped by intrinsic factors, with only the longer and heavier females being able to reproduce. The effect of population density on reproduction was negative, mediated by direct negative effects on the proportion of breeders in autumn and winter during outbreak years and by a delayed negative effect on litter size the following year. CONCLUSIONS During the main breeding season, variability of female vole reproduction is predominantly shaped by food resources, suggesting that only highly productive environment may induce vole outbreaks. During fall and winter, variability of female vole reproduction is mainly controlled by intrinsic factors, with high population density suppressing reproduction. This suggests, in this cyclic population, that negative direct density dependence on reproduction could explain winter declines after outbreaks.
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Affiliation(s)
- Adrien Pinot
- Centre d’Etudes Biologiques de Chizé (CEBC-CNRS), Beauvoir sur Niort 79360, France
- Clermont Université, VetAgro Sup, BP 10448, Clermont-Ferrand F-63000, France
| | - Bertrand Gauffre
- Centre d’Etudes Biologiques de Chizé (CEBC-CNRS), Beauvoir sur Niort 79360, France
- INRA, USC1339 (CEBC-CNRS), Beauvoir sur Niort F-79360, France
| | - Vincent Bretagnolle
- Centre d’Etudes Biologiques de Chizé (CEBC-CNRS), Beauvoir sur Niort 79360, France
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46
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Lehto Hürlimann M, Stier A, Scholly O, Criscuolo F, Bize P. Short- and long-term effects of litter size manipulation in a small wild-derived rodent. Biol Lett 2014; 10:20131096. [PMID: 24671828 DOI: 10.1098/rsbl.2013.1096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Iteroparous organisms maximize their overall fitness by optimizing their reproductive effort over multiple reproductive events. Hence, changes in reproductive effort are expected to have both short- and long-term consequences on parents and their offspring. In laboratory rodents, manipulation of reproductive efforts during lactation has however revealed few short-term reproductive adjustments, suggesting that female laboratory rodents express maximal rather than optimal levels of reproductive investment as observed in semelparous organisms. Using a litter size manipulation (LSM) experiment in a small wild-derived rodent (the common vole; Microtus arvalis), we show that females altered their reproductive efforts in response to LSM, with females having higher metabolic rates and showing alternative body mass dynamics when rearing an enlarged rather than reduced litter. Those differences in female reproductive effort were nonetheless insufficient to fully match their pups' energy demand, pups being lighter at weaning in enlarged litters. Interestingly, female reproductive effort changes had long-term consequences, with females that had previously reared an enlarged litter being lighter at the birth of their subsequent litter and producing lower quality pups. We discuss the significance of using wild-derived animals in studies of reproductive effort optimization.
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47
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van der Vinne V, Simons MJP, Reimert I, Gerkema MP. Temporal niche switching and reduced nest attendance in response to heat dissipation limits in lactating common voles (Microtus arvalis). Physiol Behav 2014; 128:295-302. [PMID: 24518859 DOI: 10.1016/j.physbeh.2014.01.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 10/27/2013] [Accepted: 01/26/2014] [Indexed: 11/24/2022]
Abstract
According to the heat dissipation limit theory, maximum metabolic turnover is limited by the capacity of the body to dissipate excess heat. Small mammals, including common voles (Microtus arvalis), face a heat dissipation limitation during lactation. Pup growth and milk production are reduced under higher ambient temperatures. Heat dissipation problems might in part be alleviated by modifying behavior, such as reducing nest attendance and being active at energetically optimal times of day. According to the circadian thermo-energetics hypothesis, animals can make use of daily ambient temperature fluctuations to alter their energetic expenditure. In this study we test whether heat challenged (housing at 30 °C compared to 21 °C) lactating common voles allocate their time differently among behaviors and whether their ultradian and circadian behavioral rhythmicity are altered. Behavior was scored every 13 min from automated picture recordings, while general locomotor activity was measured by passive infrared detectors to assess ultradian and circadian organization. The effects of ambient temperature on the ultradian organization of behavior were assessed by determining the ultradian period length and the distribution of activity within the ultradian bout. Changes in circadian organization were assessed by the distribution of activity over the light and dark phase. As a complementary measure nest temperature recordings were used to quantify nest attendance distribution between day and night. Lactating dams at 30 °C reduced the fraction of time spent on the nest while increasing the fraction of time resting without pups away from the nest. The ultradian period of locomotor activity was longer in voles housed at 30 °C during pregnancy and lactation, but not after weaning when the pups were removed. No differences in the distribution of activity within the ultradian bout could be detected. The circadian organization was also modulated by ambient temperature. Lactating voles housed at 30 °C became more day active and a loss of day-night differences in nest temperature suggests a shift of nest attendance towards the night. Reducing the time attending the nest can reduce the risk of hyperthermia, and may be the behavioral component resulting in lower milk production and hence reproductive output. Becoming more day active allows feeding and nursing of the pups during the rest phase to occur during the night at which lower ambient temperatures are expected in the field. In natural situations this strategy will increase heat dissipation and lactation capacity. Whether there are similar benefits associated with a longer ultradian period is currently unknown, but these are likely to result from decreased energy turnover at 30 °C. In conclusion, our study shows that lactating common voles facing heat dissipation problems re-organize their behavior in a way that can maximize heat dissipation capabilities and thereby optimize lactation capacity.
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Affiliation(s)
- Vincent van der Vinne
- Chronobiology Unit, Centre for Behaviour and Neurosciences, University of Groningen, PO Box 11103, NL 9747 AG Groningen, The Netherlands.
| | - Mirre J P Simons
- Chronobiology Unit, Centre for Behaviour and Neurosciences, University of Groningen, PO Box 11103, NL 9747 AG Groningen, The Netherlands
| | - Inonge Reimert
- Chronobiology Unit, Centre for Behaviour and Neurosciences, University of Groningen, PO Box 11103, NL 9747 AG Groningen, The Netherlands
| | - Menno P Gerkema
- Chronobiology Unit, Centre for Behaviour and Neurosciences, University of Groningen, PO Box 11103, NL 9747 AG Groningen, The Netherlands
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48
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Speakman JR, Al-Jothery AH, Król E, Hawkins J, Chetoui A, Saint-Lambert A, Gamo Y, Shaw SC, Valencak T, Bünger L, Hill W, Vaanholt L, Hambly C. Limits to sustained energy intake. XXII. Reproductive performance of two selected mouse lines with different thermal conductance. J Exp Biol 2014; 217:3718-32. [DOI: 10.1242/jeb.103705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Abstract
Maximal sustained energy intake (SusEI) appears limited, but the factors imposing the limit are disputed. We studied reproductive performance in two lines of mice selected for high and low food intake (MH and ML, respectively), and known to have large differences in thermal conductance (29% higher in the MH line at 21°C). When these mice raised their natural litters, their metabolisable energy intake significantly increased over the first 13 days of lactation and then reached a plateau. At peak lactation, MH mice assimilated on average 45.3 % more energy than ML mice (222.9±7.1 and 153.4±12.5 kJ day-1, N=49 and 24, respectively). Moreover, MH mice exported on average 62.3 kJ day-1 more energy as milk than ML mice (118.9±5.3 and 56.6±5.4 kJ day-1, N= subset of 32 and 21, respectively). The elevated milk production of MH mice enabled them to wean litters (65.2±2.1 g) that were on average 50.2% heavier than litters produced by ML mothers (43.4±3.0 g), and pups that were on average 27.2% heavier (9.9±0.2 and 7.8±0.2 g, respectively). Lactating mice in both lines had significantly longer and heavier guts compared to non-reproductive mice. However, inconsistent with the central limit hypothesis, the ML mice had significantly longer and heavier intestines than MH mice. An experiment where the mice raised litters of the opposing line demonstrated that lactation performance was not limited by offspring growth capacity. Our findings are consistent with the idea that the SusEI at peak lactation is constrained by the capacity of the mothers to dissipate body heat.
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Affiliation(s)
| | | | | | | | | | | | - Yuko Gamo
- University of Aberdeen, United Kingdom
| | | | | | - Lutz Bünger
- Scotland's Rural College (SRUC), United Kingdom
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49
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Szafrańska PA, Zub K, Wieczorek M, Książek A, Speakman JR, Konarzewski M. Shaving increases daily energy expenditures in free living root voles. J Exp Biol 2014; 217:3964-7. [DOI: 10.1242/jeb.103754] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Experimental manipulation of energy expenditure has long been recognized as an effective means for identifying causative effects and avoiding confounded interpretations arising from spurious correlations. This approach has been successfully applied mainly in studies on birds, particularly on reproducing adults, while manipulations in mammals have proved more problematic. Here we tested the hypothesis that shaving off 50% of the dorsal pelage should effectively increase energy expenditure in the wild root voles (Microtus oeconomus) in their natural environment. We measured daily energy expenditures (DEE), using doubly labelled water (DLW), in shaved and unshaved voles at the beginning of winter. The difference in DEE (corrected for body mass and year effects) between experimental and control group fluctuated from 11.5% to 17.3%. Probability of recapture over the 3-days DEE assay was strongly dependent on body mass but did not differ between shaved and unshaved animals, however the prevalence of larger (heavier) shaved individuals was observed. Shaved animals lost more weight between the release and recapture. Shaving therefore appears an effective method of increasing costs of total daily energy expenditures in wild endotherms in their natural environment.
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Affiliation(s)
| | - Karol Zub
- Mammal Research Institute Polish Academy of Sciences, Poland
| | | | | | - John R. Speakman
- University of Aberdeen, Scotland; Institute of Genetics and Developmental Biology, CAS, China
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Yang DB, Xu YC, Wang DH, Speakman JR. Effects of reproduction on immuno-suppression and oxidative damage, and hence support or otherwise for their roles as mechanisms underpinning life history trade-offs, are tissue and assay dependent. ACTA ACUST UNITED AC 2013; 216:4242-50. [PMID: 23997195 DOI: 10.1242/jeb.092049] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Life history parameters appear to be traded off against each other, but the physiological mechanisms involved remain unclear. One hypothesis is that potentially energetically costly processes such as immune function and protection from oxidative stress may be compromised during reproductive attempts because of selective resource allocation. Lower temperatures also impose energy costs, and hence allocation decisions might be more pronounced when animals are forced to reproduce in the cold. Here, we experimentally tested whether reproduction at different ambient temperatures was associated with elevated oxidative stress and suppressed immune function in Mongolian gerbils (Meriones unguiculatus). Using a variety of different markers for both immune function and oxidative stress, we found that some measures of immune function (serum bactericidal capacity and size of the thymus) were significantly suppressed, while some measures of oxidative protection [serum superoxide dismutase (SOD) activity and glutathione peroxidase (GPx) activity] were also reduced, and a marker of oxidative damage (protein carbonyls in serum) was increased in lactating compared with non-reproductive gerbils. These changes were in line with the selective resource allocation predictions. However, the phytohaemagglutinin response and serum total immunoglobulin (IgG) were not suppressed, and other markers of oxidative damage [malondialdehyde (MDA) (TBARS) and protein carbonyls in the liver] were actually lower in lactating compared with non-reproductive gerbils, consistent with increased levels of SOD activity and total antioxidant capacity in the liver. These latter changes were opposite of the expectations based on resource allocation. Furthermore, other measures of protection (GPx levels in the liver and protein thiols in both serum and liver) and damage [MDA (TBARS) in serum] were unrelated to reproductive status. Ambient temperature differences did not impact on these patterns. Collectively, our results indicated that the inferred effects of reproduction on immunosuppression and oxidative damage, and hence support or otherwise for particular physiological mechanisms that underpin life history trade-offs, are critically dependent on the exact markers and tissues used. This may be because during reproduction individuals selectively allocate protection to some key tissues, but sacrifice protection of others.
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Affiliation(s)
- Deng-Bao Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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