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Geiser F, Wen J, Sukhchuluun G, Chi QS, Wang DH. Precocious Torpor in an Altricial Mammal and the Functional Implications of Heterothermy During Development. Front Physiol 2019; 10:469. [PMID: 31068837 PMCID: PMC6491829 DOI: 10.3389/fphys.2019.00469] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 04/04/2019] [Indexed: 12/01/2022] Open
Abstract
Most mammals and birds are altricial, small and naked at birth/hatching. They attain endothermic thermoregulation at a fraction of their adult size at a vulnerable stage with high heat loss when many could profit from using torpor for energy conservation. Nevertheless, detailed data on the interrelations between torpor expression and development of endothermic thermoregulation are currently restricted to <0.1% of extant endotherms. We investigated at what age and body mass (BM) desert hamsters (Phodopus roborovskii), wild-caught in Inner Mongolia and born in autumn/early winter when environmental temperatures in the wild begin to decrease, are able to defend their body temperature (Tb) at an ambient temperature (Ta) of ∼21°C and how soon thereafter they could express torpor. Measurements of surface temperatures via infrared thermometer and thermal camera show that although neonate hamsters (BM 0.9 ± 0.1 g) cooled rapidly to near Ta, already on day 15 (BM 5.5 ± 0.2 g) they could defend a high and constant Tb. As soon as day 16 (BM 5.8 ± 0.2 g), when their maximum activity metabolism (measured as oxygen consumption) approached maxima measured in vertebrates, animals were able to enter torpor for several hours with a reduction of metabolism by >90%, followed by endothermic arousal. Over the next weeks, torpor depth and duration decreased together with a reduction in resting metabolic rate at Ta 30–32°C. Our data show that development of endothermy and torpor expression in this altricial hamster is extremely fast. The results suggest that precocious torpor by juvenile hamsters in autumn and winter is an important survival tool in their vast and harsh Asian desert habitats, but likely also for many other small mammals and birds worldwide.
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Affiliation(s)
- Fritz Geiser
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia
| | - Jing Wen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Gansukh Sukhchuluun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Mammalian Ecology Laboratory, Institute of General and Experimental Biology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia
| | - Qing-Sheng Chi
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - De-Hua Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of the Chinese Academy of Sciences, Beijing, China
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Zhang XY, Sukhchuluun G, Bo TB, Chi QS, Yang JJ, Chen B, Zhang L, Wang DH. Correction to: Huddling remodels gut microbiota to reduce energy requirements in a small mammal species during cold exposure. Microbiome 2018; 6:126. [PMID: 30001201 PMCID: PMC6044083 DOI: 10.1186/s40168-018-0509-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Following publication of the original article [1], the authors reported an error in the caption of Fig. 4.
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Affiliation(s)
- Xue-Ying Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gansukh Sukhchuluun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ting-Bei Bo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qing-Sheng Chi
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun-Jie Yang
- College of Life Science, Shandong Normal University, Ji'nan, 250014, China
| | - Bin Chen
- College of Life Science, Shandong Normal University, Ji'nan, 250014, China
| | - Lei Zhang
- College of Life Science, Shandong Normal University, Ji'nan, 250014, China
- Microbiome Research Center, Shandong Institutes for Food and Drug Control, Ji'nan, 250101, China
| | - De-Hua Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Zhang XY, Sukhchuluun G, Bo TB, Chi QS, Yang JJ, Chen B, Zhang L, Wang DH. Huddling remodels gut microbiota to reduce energy requirements in a small mammal species during cold exposure. Microbiome 2018; 6:103. [PMID: 29884232 PMCID: PMC5994089 DOI: 10.1186/s40168-018-0473-9] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 04/09/2018] [Indexed: 06/01/2023]
Abstract
BACKGROUND Huddling is highly evolved as a cooperative behavioral strategy for social mammals to maximize their fitness in harsh environments. Huddling behavior can change psychological and physiological responses. The coevolution of mammals with their microbial communities confers fitness benefits to both partners. The gut microbiome is a key regulator of host immune and metabolic functions. We hypothesized that huddling behavior altered energetics and thermoregulation by shaping caecal microbiota in small herbivores. Brandt's voles (Lasiopodomys brandtii) were maintained in a group (huddling) or as individuals (separated) and were exposed to warm (23 ± 1 °C) and cold (4 ± 1 °C) air temperatures (Ta). RESULTS Voles exposed to cold Ta had higher energy intake, resting metabolic rate (RMR) and nonshivering thermogenesis (NST) than voles exposed to warm Ta. Huddling voles had lower RMR and NST than separated voles in cold. In addition, huddling voles had a higher surface body temperature (Tsurface), but lower core body temperature (Tcore) than separated voles, suggesting a lower set-point of Tcore in huddling voles. Both cold and huddling induced a marked variation in caecal bacterial composition, which was associated with the lower Tcore. Huddling voles had a higher α and β-diversity, abundance of Lachnospiraceae and Veillonellaceae, but lower abundance of Cyanobacteria, Tenericutes, TM7, Comamonadaceae, and Sinobacteraceae than separated voles. Huddling or cold resulted in higher concentrations of short-chain fatty acids (SCFAs), particularly acetic acid and butyric acid when compared to their counterparts. Transplantation of caecal microbiota from cold-separated voles but not from cold-huddling voles induced significant increases in energy intake and RMR compared to that from warm-separated voles. CONCLUSIONS These findings demonstrate that the remodeling of gut microbiota, which is associated with a reduction in host Tcore, mediates cold- and huddling-induced energy intake and thermoregulation and therefore orchestrates host metabolic and thermal homeostasis. It highlights the coevolutionary mechanism of host huddling and gut microbiota in thermoregulation and energy saving for winter survival in endotherms.
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Affiliation(s)
- Xue-Ying Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gansukh Sukhchuluun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ting-Bei Bo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qing-Sheng Chi
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun-Jie Yang
- College of Life Science, Shandong Normal University, Ji'nan, 250014, China
| | - Bin Chen
- College of Life Science, Shandong Normal University, Ji'nan, 250014, China
| | - Lei Zhang
- College of Life Science, Shandong Normal University, Ji'nan, 250014, China
- Microbiome Research Center, Shandong Institutes for Food and Drug Control, Ji'nan, 250101, China
| | - De-Hua Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Sukhchuluun G, Zhang XY, Chi QS, Wang DH. Huddling Conserves Energy, Decreases Core Body Temperature, but Increases Activity in Brandt's Voles ( Lasiopodomys brandtii). Front Physiol 2018; 9:563. [PMID: 29867585 PMCID: PMC5968109 DOI: 10.3389/fphys.2018.00563] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 04/30/2018] [Indexed: 11/13/2022] Open
Abstract
Huddling as social thermoregulatory behavior is commonly used by small mammals to reduce heat loss and energy expenditure in the cold. Our study aimed to determine the effect of huddling behavior on energy conservation, thermogenesis, core body temperature (Tb) regulation and body composition in Brandt's voles (Lasiopodomys brandtii). Adult captive-bred female Brandt's voles (n = 124) (~50 g) in 31 cages with 4 individuals each were exposed to cool (23 ± 1°C) and cold (4 ± 1°C) ambient temperatures (Ta) and were allowed to huddle or were physically separated. The cold huddling (Cold-H) groups significantly reduced food intake by 29% and saved digestible energy 156.99 kJ/day compared with cold separated groups (Cold-S); in cool huddling groups (Cool-H) the reduction in food intake was 26% and digestible energy was saved by 105.19 kJ/day in comparison to the separated groups (Cool-S). Resting metabolic rate (RMR) of huddling groups was 35.7 and 37.2% lower than in separated groups at cold and cool Tas, respectively. Maximum non-shivering thermogenesis (NSTmax) of huddling voles was not affected by Ta, but in Cold-S voles it was significantly increased in comparison to Cool-S. Huddling groups decreased wet thermal conductance by 39% compared with separated groups in the cold, but not in the cool Ta. Unexpectedly, huddling voles significantly decreased Tb by 0.25 - 0.50°C at each Ta. Nevertheless, activity of Cold-H voles was higher than in Cold-S voles. Thus, huddling is energetically highly effective because of reduced metabolic rate, thermogenic capacity and relaxed Tb regulation despite the increase of activity. Therefore, Brandt's voles can remain active and maintain their body condition without increased energetic costs during cold exposure. This study highlights the ecological significance of huddling behavior for maintenance of individual fitness at low costs, and thus survival of population during severe winter in small mammals.
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Affiliation(s)
- Gansukh Sukhchuluun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xue-Ying Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qing-Sheng Chi
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - De-Hua Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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