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Fan W, Engborg CB, Sciolino NR. Locus Ceruleus Dynamics Are Suppressed during Licking and Enhanced Postlicking Independent of Taste Novelty. eNeuro 2024; 11:ENEURO.0535-23.2024. [PMID: 38649278 PMCID: PMC11036117 DOI: 10.1523/eneuro.0535-23.2024] [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: 12/15/2023] [Revised: 03/26/2024] [Accepted: 04/01/2024] [Indexed: 04/25/2024] Open
Abstract
Attending to salient sensory attributes of food, such as tastes that are new, displeasing, or unexpected, allows the procurement of nutrients without food poisoning. Exposure to new tastes is known to increase norepinephrine (NE) release in taste processing forebrain areas, yet the central source for this release is unknown. Locus ceruleus norepinephrine neurons (LC-NE) emerge as a candidate in signaling salient information about taste, as other salient sensory stimuli (e.g., visual, auditory, somatosensation) are known to activate LC neurons. To determine if LC neurons are sensitive to features of taste novelty, we used fiber photometry to record LC-NE activity in water-restricted mice that voluntarily licked either novel or familiar substances of differential palatability (saccharine, citric acid). We observed that LC-NE activity was suppressed during lick bursts and transiently activated upon the termination of licking and that these dynamics were independent of the familiarity of the substance consumed. We next recorded LC dynamics during brief and unexpected consumption of tastants and found no increase in LC-NE activity, despite their responsiveness to visual and auditory stimuli, revealing selectivity in LC's responses to salient sensory information. Our findings suggest that LC activity during licking is not influenced by taste novelty, implicating a possible role for non-LC noradrenergic nuclei in signaling critical information about taste.
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Affiliation(s)
- Will Fan
- Departments of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269
| | - Christopher B Engborg
- Departments of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269
| | - Natale R Sciolino
- Departments of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269
- Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269
- Psychological Sciences, University of Connecticut, Storrs, Connecticut 06269
- Institute for the Brain and Cognitive Sciences, University of Connecticut, Storrs, Connecticut 06269
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2
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El-Sabaawi RW, Lemmen KD, Jeyasingh PD, Declerck SAJ. SEED: A framework for integrating ecological stoichiometry and eco-evolutionary dynamics. Ecol Lett 2023; 26 Suppl 1:S109-S126. [PMID: 37840025 DOI: 10.1111/ele.14285] [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: 11/07/2022] [Revised: 06/01/2023] [Accepted: 06/04/2023] [Indexed: 10/17/2023]
Abstract
Characterising the extent and sources of intraspecific variation and their ecological consequences is a central challenge in the study of eco-evolutionary dynamics. Ecological stoichiometry, which uses elemental variation of organisms and their environment to understand ecosystem patterns and processes, can be a powerful framework for characterising eco-evolutionary dynamics. However, the current emphasis on the relative content of elements in the body (i.e. organismal stoichiometry) has constrained its application. Intraspecific variation in the rates at which elements are acquired, assimilated, allocated or lost is often greater than the variation in organismal stoichiometry. There is much to gain from studying these traits together as components of an 'elemental phenotype'. Furthermore, each of these traits can have distinct ecological effects that are underappreciated in the current literature. We propose a conceptual framework that explores how microevolutionary change in the elemental phenotype occurs, how its components interact with each other and with other traits, and how its changes can affect a wide range of ecological processes. We demonstrate how the framework can be used to generate novel hypotheses and outline pathways for future research that enhance our ability to explain, analyse and predict eco-evolutionary dynamics.
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Affiliation(s)
- Rana W El-Sabaawi
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Kimberley D Lemmen
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Punidan D Jeyasingh
- Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Steven A J Declerck
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Department of Biology, Laboratory of Aquatic Ecology, Evolution and Conservation, KULeuven, Leuven, Belgium
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3
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Filipiak ZM, Ollerton J, Filipiak M. Uncovering the significance of the ratio of food K:Na in bee ecology and evolution. Ecology 2023; 104:e4110. [PMID: 37232411 DOI: 10.1002/ecy.4110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/04/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023]
Abstract
Bees provide important ecological services, and many species are threatened globally, yet our knowledge of wild bee ecology and evolution is limited. While evolving from carnivorous ancestors, bees had to develop strategies for coping with limitations imposed on them by a plant-based diet, with nectar providing energy and essential amino acids and pollen as an extraordinary, protein- and lipid-rich food nutritionally similar to animal tissues. Both nectar and pollen display one characteristic common to plants, a high ratio of potassium to sodium (K:Na), potentially leading to bee underdevelopment, health problems, and death. We discuss why and how the ratio of K:Na contributes to bee ecology and evolution and how considering this factor in future studies will provide new knowledge, more accurately depicting the relationship of bees with their environments. Such knowledge is essential for understanding how plants and bees function and interact and is needed to effectively protect wild bees.
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Affiliation(s)
- Zuzanna M Filipiak
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
| | - Jeff Ollerton
- Faculty or Arts, Science and Technology, University of Northampton, Northampton, UK
- Kunming Institute of Botany, Kunming, China
| | - Michał Filipiak
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
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4
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Choi J, Lee L, Maro A, Corl A, McGuire JA, Bowie RCK, Dudley R. Hummingbird ingestion of low-concentration ethanol within artificial nectar. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230306. [PMID: 37351493 PMCID: PMC10282586 DOI: 10.1098/rsos.230306] [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: 03/22/2023] [Accepted: 06/01/2023] [Indexed: 06/24/2023]
Abstract
Both frugivores and nectarivores are potentially exposed to dietary ethanol produced by fermentative yeasts which metabolize sugars. Some nectarivorous mammals exhibit a preference for low-concentration ethanol solutions compared to controls of comparable caloric content, but behavioural responses to ethanol by nectar-feeding birds are unknown. We investigated dietary preference by Anna's Hummingbirds (Calypte anna) for ethanol-enhanced sucrose solutions. Via repeated binary-choice experiments, three adult male hummingbirds were exposed to sucrose solutions containing 0%, 1% or 2% ethanol; rates of volitional nectar consumption were measured over a 3 h interval. Hummingbirds did not discriminate between 0% and 1% ethanol solutions, but exhibited significantly reduced rates of consumption of a 2% ethanol solution. Opportunistic measurements of ethanol concentrations within hummingbird feeders registered values peaking at about 0.05%. Ethanol at low concentrations (i.e. up to 1%) is not aversive to Anna's Hummingbirds and may be characteristic of both natural and anthropogenic nectars upon which they feed. Given high daily amounts of nectar consumption by hummingbirds, chronic physiological exposure to ethanol can thus be substantial, although naturally occurring concentrations within floral nectar are unknown.
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Affiliation(s)
- Julia Choi
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Lilianne Lee
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Aleksey Maro
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Ammon Corl
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Jimmy A. McGuire
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Rauri C. K. Bowie
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Robert Dudley
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
- Smithsonian Tropical Research Institute, Balboa, Republic of Panama
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5
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Schwerdtfeger J, Krause A, Kalbe C, Mazzuoli-Weber G, Eggert A, Puppe B, Kuhla B, Röttgen V. Endocannabinoid administration affects taste preference and the expression of cannabinoid and opioid receptors in the amygdala of early lactating cows. Sci Rep 2023; 13:4967. [PMID: 36973308 PMCID: PMC10042870 DOI: 10.1038/s41598-023-31724-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 03/16/2023] [Indexed: 03/29/2023] Open
Abstract
The aim of the study was to investigate the influence of intraperitoneal N-arachidonoylethanolamide (AEA) on taste preference for feed and water, tongue taste receptor signalling (TAS1R2, GNAT3), and endocannabinoid (CNR1, CNR2, GPR55) and opioid (OPRD1, OPRK1, OPRM1, OPRL1) receptors in the amygdala and nucleus accumbens in periparturient cows. We conducted taste preference tests using unaltered, umami-tasting, and sweet-tasting water and feed, before and after calving. After calving, eight cows received AEA injections (3 µg/(kg bodyweight × day), 25 days), whereas eight control (CON) cows received saline injections. Tissue was sampled 30 days after calving. Before calving, both cow groups preferred sweet-tasting feed and umami-tasting water. After calving, only the AEA-treated group preferred sweet-tasting feed, whereas the CON group showed no clear taste preference. In the amygdala, the mRNA expression of CNR1, OPRD1 (left hemisphere) and OPRK1 (right hemisphere) was lower in AEA animals than in CON animals, whereas no differences were found in the nucleus accumbens and tongue taste receptor expression. In conclusion, AEA administration enhanced existing taste preferences and reduced the expression of specific endocannabinoid and opioid receptors in the amygdala. The results support endocannabinoid-opioid interactions in the control of taste-dependent feed preference in early lactating cows.
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Affiliation(s)
- Jessica Schwerdtfeger
- Institute of Nutritional Physiology 'Oskar Kellner', Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Annika Krause
- Institute of Behavioural Physiology, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Claudia Kalbe
- Institute of Muscle Biology and Growth, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Gemma Mazzuoli-Weber
- Institute for Physiology and Cell Biology, University of Veterinary Medicine, 30173, Hannover, Germany
| | - Anja Eggert
- Institute of Genetics and Biometry, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Birger Puppe
- Institute of Behavioural Physiology, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
- Behavioural Sciences, Faculty of Agricultural and Environmental Sciences, University of Rostock, Justus-Von-Liebig-Weg 6B, 18059, Rostock, Germany
| | - Björn Kuhla
- Institute of Nutritional Physiology 'Oskar Kellner', Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Volker Röttgen
- Institute of Behavioural Physiology, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
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6
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Smith S, Mohamed A, Amaral JR, Kusi N, Smith A, Gordon SP, López-Sepulcre A. Rapid evolution of diet choice in an introduced population of Trinidadian guppies. Biol Lett 2023; 19:20220443. [PMID: 36693425 PMCID: PMC9873468 DOI: 10.1098/rsbl.2022.0443] [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: 09/26/2022] [Accepted: 12/16/2022] [Indexed: 01/26/2023] Open
Abstract
Eco-evolutionary theory has brought an interest in the rapid evolution of functional traits. Among them, diet is an important determinant of ecosystem structure, affecting food web dynamics and nutrient cycling. However, it is largely unknown whether diet, or diet preference, has a hereditary basis and can evolve on contemporary timescales. Here, we study the diet preferences of Trinidadian guppies Poecilia reticulata collected from directly below an introduction site of fish transplanted from a high-predation environment into a low predation site where their densities and competition increased. Behavioural assays on F2 common garden descendants of the ancestral and derived populations showed that diet preference has rapidly evolved in the introduced population in only 12 years (approx. 36 generations). Specifically, we show that the preference for high-quality food generally found in high-predation guppies is lost in the newly derived low-predation population, who show an inertia toward the first encountered food. This result is predicted by theory stating that organisms should evolve less selective diets under higher competition. Demonstrating that diet preference can show rapid and adaptive evolution is important to our understanding of eco-evolutionary feedbacks and the role of evolution in ecosystem dynamics.
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Affiliation(s)
- Shawna Smith
- Department of Biology, Washington University, St. Louis, MO 63130, USA
| | - Amina Mohamed
- Department of Biology, Washington University, St. Louis, MO 63130, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jeferson Ribeiro Amaral
- Department of Biology, Washington University, St. Louis, MO 63130, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Nana Kusi
- Department of Biology, Washington University, St. Louis, MO 63130, USA
| | - Alexander Smith
- Department of Biology, Washington University, St. Louis, MO 63130, USA
| | - Swanne P. Gordon
- Department of Biology, Washington University, St. Louis, MO 63130, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Andrés López-Sepulcre
- Department of Biology, Washington University, St. Louis, MO 63130, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
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7
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Zhang C, Kang Y, Yao B, An K, Pu Q, Wang Z, Sun X, Su J. Increased availability of preferred food and decreased foraging costs from degraded grasslands lead to rodent pests in the Qinghai-Tibet Plateau. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.971429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The increased population density of rodent species during ongoing grassland degradation further deteriorates its conditions. Understanding the effects of grassland degradation on rodent feeding habits is of great value for optimizing grassland management strategies. In this study, lightly degraded (LD), moderately degraded (MD), severely degraded (SD), and reseeded grassland (RG) were selected and their plant resources and soil physical properties were investigated. In addition, the study used ITS2 barcode combined with the Illumina MiSeq sequencing method to analyze the food composition and proportion of plateau zokors in different grassland conditions. The results showed that, with grassland degradation, plant biomass decreased, but the relative proportion of forbs increased (LD: 32.05 ± 3.89%; MD: 28.97 ± 2.78%; SD: 49.16 ± 4.67% and RG: 10.93 ± 1.53%). Forbs were the main food of the plateau zokor, accounting for more than 90% of their diet, and the animal had a clear preference for Potentilla species; the soil compaction of feeding habits showed a decreasing trend in the 10–25 cm soil layer, suggesting a decreased foraging cost. Nutritional analysis showed that the stomach content of crude protein in zokors feeding on MD grassland was significantly higher than that of animals feeding on the other grassland types. Structural equation modeling showed that soil physical properties and the relative biomass of forbs had significant (P < 0.05) and extremely significant (P < 0.001) impacts on the population density of plateau zokors, with direct impact contribution rates of 0.20 and 0.63. As the severity of grassland degradation increased, although the aboveground and underground biomass of the plants decreased, the proportion of food preferred by the plateau zokor increased, and the corresponding changes in the feeding environment resulted in decreased foraging energy expenditure, thereby increasing the suitability of the degraded grassland for the plateau zokor. Compared with degraded grassland, the food diversity and evenness of zokors increased, the food niche width enlarged, and the proportion of weeds decreased in RG, which increased the difficulty of obtaining food. Reseeding in grassland management is therefore an effective way to control plateau zokors.
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In defense of elemental currencies: can ecological stoichiometry stand as a framework for terrestrial herbivore nutritional ecology? Oecologia 2022; 199:27-38. [PMID: 35396976 DOI: 10.1007/s00442-022-05160-5] [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: 11/01/2021] [Accepted: 04/01/2022] [Indexed: 10/18/2022]
Abstract
Nutritional ecologists aim to predict population or landscape-level effects of food availability, but the tools to extrapolate nutrition from small to large extents are often lacking. The appropriate nutritional ecology currencies should be able to represent consumer responses to food while simultaneously be simple enough to expand such responses to large spatial extents and link them to ecosystem functioning. Ecological stoichiometry (ES), a framework of nutritional ecology, can meet these demands, but it is typically associated with ecosystem ecology and nutrient cycling, and less often used to study wildlife nutrition. Despite the emerging zoogeochemical evidence that animals, and thus their diets, play critical roles in nutrient movement, wildlife nutritional ecology has not fully embraced ES, and ES has not incorporated nutrition in many wildlife studies. Here, we discuss how elemental currencies are "nutritionally, organismally, and ecologically explicit" in the context of terrestrial herbivore nutritional ecology. We add that ES and elemental currencies offer a means to measure resource quality across landscapes and compare nutrient availability among regions. Further, we discuss ES shortcomings and solutions, and list future directions to advance the field. As ecological studies increasingly grow in spatial extent, and attempt to link multiple levels of biological organization, integrating more simple and unifying currencies into nutritional studies, like elements, is necessary for nutritional ecology to predict herbivore occurrences and abundances across regions.
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9
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Frank HER, Amato K, Trautwein M, Maia P, Liman ER, Nichols LM, Schwenk K, Breslin PAS, Dunn RR. The evolution of sour taste. Proc Biol Sci 2022; 289:20211918. [PMID: 35135352 PMCID: PMC8826303 DOI: 10.1098/rspb.2021.1918] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The evolutionary history of sour taste has been little studied. Through a combination of literature review and trait mapping on the vertebrate phylogenetic tree, we consider the origin of sour taste, potential cases of the loss of sour taste, and those factors that might have favoured changes in the valence of sour taste-from aversive to appealing. We reconstruct sour taste as having evolved in ancient fish. By contrast to other tastes, sour taste does not appear to have been lost in any major vertebrate taxa. For most species, sour taste is aversive. Animals, including humans, that enjoy the sour taste triggered by acidic foods are exceptional. We conclude by considering why sour taste evolved, why it might have persisted as vertebrates made the transition to land and what factors might have favoured the preference for sour-tasting, acidic foods, particularly in hominins, such as humans.
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Affiliation(s)
- Hannah E. R. Frank
- Department of Crop and Soil Sciences North Carolina State University, Raleigh, USA
| | - Katie Amato
- Department of Anthropology, Northwestern University, Evanston, IL, USA
| | - Michelle Trautwein
- Entomology Department, Institute for Biodiversity Science and Sustainability, California Academy of Sciences, San Francisco, USA
| | - Paula Maia
- Department of Anthropology, Northwestern University, Evanston, IL, USA
| | - Emily R. Liman
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Lauren M. Nichols
- Department of Applied Ecology, North Carolina State University, Raleigh, USA
| | - Kurt Schwenk
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA
| | - Paul A. S. Breslin
- Department of Nutritional Sciences, Rutgers The State University of New Jersey, New Brunswick, NJ, USA,Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Robert R. Dunn
- Department of Applied Ecology, North Carolina State University, Raleigh, USA,Center for Evolutionary Hologenomics, University of Copenhagen, Copenhagen, Denmark
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10
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Liu G, Zhang S, Zhao X, Li C, Gong M. Advances and Limitations of Next Generation Sequencing in Animal Diet Analysis. Genes (Basel) 2021; 12:genes12121854. [PMID: 34946803 PMCID: PMC8701983 DOI: 10.3390/genes12121854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 02/07/2023] Open
Abstract
Diet analysis is a critical content of animal ecology and the diet analysis methods have been constantly improving and updating. Contrary to traditional methods of high labor intensity and low resolution, the next generation sequencing (NGS) approach has been suggested as a promising tool for dietary studies, which greatly improves the efficiency and broadens the application range. Here we present a framework of adopting NGS and DNA metabarcoding into diet analysis, and discuss the application in aspects of prey taxa composition and structure, intra-specific and inter-specific trophic links, and the effects of animal feeding on environmental changes. Yet, the generation of NGS-based diet data and subsequent analyses and interpretations are still challenging with several factors, making it possible still not as widely used as might be expected. We suggest that NGS-based diet methods must be furthered, analytical pipelines should be developed. More application perspectives, including nutrient geometry, metagenomics and nutrigenomics, need to be incorporated to encourage more ecologists to infer novel insights on they work.
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Affiliation(s)
- Gang Liu
- Key Laboratory of Wetland Ecological Function and Restoration in Beijing City, Wetland Research Institute of Chinese Academy of Forestry Sciences, Beijing 100091, China; (G.L.); (X.Z.); (C.L.)
| | - Shumiao Zhang
- Beijing Milu Ecological Research Center, Beijing 100076, China;
| | - Xinsheng Zhao
- Key Laboratory of Wetland Ecological Function and Restoration in Beijing City, Wetland Research Institute of Chinese Academy of Forestry Sciences, Beijing 100091, China; (G.L.); (X.Z.); (C.L.)
| | - Chao Li
- Key Laboratory of Wetland Ecological Function and Restoration in Beijing City, Wetland Research Institute of Chinese Academy of Forestry Sciences, Beijing 100091, China; (G.L.); (X.Z.); (C.L.)
| | - Minghao Gong
- Key Laboratory of Wetland Ecological Function and Restoration in Beijing City, Wetland Research Institute of Chinese Academy of Forestry Sciences, Beijing 100091, China; (G.L.); (X.Z.); (C.L.)
- Correspondence: ; Tel.: +86-010-62884159
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11
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Mahandran V, Murugan CM, Anisha PS, Wang G, Chen J, Nathan PT. Chemical components change along the ontogeny of a bat fruit (Neolamarckia cadamba) with ripening asynchrony in favour of its fruit selection and seed dispersal. Naturwissenschaften 2021; 108:46. [PMID: 34581964 DOI: 10.1007/s00114-021-01756-8] [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: 08/10/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 10/20/2022]
Abstract
An asynchronous fruit-ripening strategy can enhance the chance of seed dispersal by providing ripe fruits for an extended period to foragers. However, mechanisms associated with this strategy that can facilitate seed dispersal are understudied. This study aimed to investigate whether the chemical components (minerals and secondary metabolites) of a bat fruit with ripening asynchrony change along its ontogeny (Rubiaceae: Neolamarckia cadamba). We predicted that the seed-to-pulp ratio would increase along with fruit ripeness. The chemical components of the fruit were also predicted to change along their ontogenesis in favour of fruit selection and seed dispersal by fruit bats. Our study shows that the asynchronous fruiting strategy limited the number of ripe fruits daily so that fruits were available at a steady rate. As predicted, the seed-to-pulp ratio of each fruit increased along with fruit development. A fruit's mineral concentration also increased as fruit developed, with a sharp jump at full ripeness, when fruit colour also changed. In contrast, the concentration of secondary metabolite compositions decreased gradually during the process of ontogeny. Fruit bats (Pteropodidae: Pteropus giganteus and Cynopterus sphinx) were the only nocturnal frugivore visitors of these trees and their fruit selection was driven by fruit size and colour. Both bats preferably consumed ripe fruits, which had a higher concentration of attractants (essential minerals) and a lower concentration of deterrents (secondary metabolites), supplemented with a higher seed-to-pulp ratio. The bats exhibited different foraging patterns and home ranges resulting in dispersal (as measured by feeding roost location) occurring across different spatial scales. Our study shows that the chemical components involved in an asynchronous fruit-ripening process could select for extended fruit availability by intensifying the demand for each ripe fruit among legitimate seed dispersers, which increases the likelihood of fruits being dispersed away from parent crowns.
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Affiliation(s)
- Valliyappan Mahandran
- CAS-Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China
| | | | | | - Gang Wang
- CAS-Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China
| | - Jin Chen
- CAS-Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China
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