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Wright M, Oleson L, Witty R, Fritz KA, Kirschman LJ. Infection Causes Trade-Offs between Development and Growth in Larval Amphibians. Physiol Biochem Zool 2023; 96:430-437. [PMID: 38237190 DOI: 10.1086/727729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
AbstractTrade-offs between life history traits are context dependent; they vary depending on environment and life stage. Negative associations between development and growth often characterize larval life stages. Both growth and development consume large parts of the energy budget of young animals. The metabolic rate of animals should reflect differences in growth and developmental rates. Growth and development can also have negative associations with immune function because of their costs. We investigated how intraspecific variation in growth and development affected the metabolism of larval amphibians and whether intraspecific variation in growth, development, and metabolic rate could predict mortality and viral load in larvae infected with ranavirus. We also compared the relationship between growth and development before and after infection with ranavirus. We hypothesized that growth and development would affect metabolism and predicted that each would have a positive correlation with metabolic rate. We further hypothesized that allocation toward growth and development would increase ranavirus susceptibility and therefore predicted that larvae with faster growth, faster development, and higher metabolic rates would be more likely to die from ranavirus and have higher viral loads. Finally, we predicted that growth rate and developmental rate would have a negative association. Intraspecific variation in growth rate and developmental rate did not affect metabolism. Growth rate, developmental rate, and metabolism did not predict mortality from ranavirus or viral load. Larvae infected with ranavirus exhibited a trade-off between developmental rate and growth rate that was absent in uninfected larvae. Our results indicate a cost of ranavirus infection that is potentially due to both the infection-induced anorexia and the cost of infection altering priority rules for resource allocation.
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Kirschman LJ, Khadjinova A, Ireland K, Milligan-Myhre KC. Early life disruption of the microbiota affects organ development and cytokine gene expression in threespine stickleback. Integr Comp Biol 2020; 63:icaa136. [PMID: 32970813 PMCID: PMC10388389 DOI: 10.1093/icb/icaa136] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
The microbiota that inhabits vertebrates exerts strong effects on host physiology and can be crucial to the development of a normal phenotype. This includes development of the immune system, somatic growth and maintenance, and morphogenesis. However, the genetic background of the host can also affect these life history traits. To this end, we investigated the effects of the microbiota on growth, development, and immune gene expression on two populations of threespine stickleback (Gasterosteus aculeatus), one anadromous and one freshwater. We tested the hypotheses that microbial colonization and the genetic background of the host would affect survival, cytokine gene expression, growth, and development. We raised in vitro crosses of stickleback larvae with and without conventional microbiota. We then exposed all these treatments to Vibrio anguillarum, a potential fish pathogen, in a full factorial design. We found stickleback raised without conventional microbiota had smaller swim bladders relative to those raised with conventional microbiota. Stickleback raised with conventional microbiota exhibited small increases in cytokine gene expression. We found no differences in growth or survival regardless of treatment. These results are consistent with other investigations that show microbiota disruption, in early life, can alter host organ and tissue development and immune responses.
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Affiliation(s)
- Lucas J Kirschman
- Department Biology, Southeast Missouri University, 1 University Plaza, Cape Girardeau, MO 63701, USA
| | | | - Kelly Ireland
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, USA
| | - Kathryn C Milligan-Myhre
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, USA
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269-3125, USA
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Kirschman LJ, Morales D, Crawford E, Zera AJ, Warne RW. Sex and life history shape the strength of cellular and humoral immune responses in a wing dimorphic cricket. J Insect Physiol 2019; 116:70-76. [PMID: 31029600 DOI: 10.1016/j.jinsphys.2019.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 06/09/2023]
Abstract
Immune function is a complex collection of responses that often trade-off with one another and with other life history traits, because of the high costs of mounting and maintaining immune responses. Animals, even those from the same populations, may emphasize different aspects of immune function depending on their habitat and phenotype. For example, host population density mediates the threat from density-dependent parasites. Animals at high densities may emphasize fast-acting humoral responses, while those at low densities may favor slower, but more specific, cellular responses. However, these predictions may be dependent on other life history traits, like sex, which is associated with variation in many immune responses. We used wing dimorphic Gryllus firmus crickets to test humoral responses, measured by lysozyme and phenoloxidase activities, and cellular immune responses, measured by encapsulation, between morphs and sex. We found that both morphs and sexes differed in aspects of immune function. Long wing morphs had stronger encapsulation responses than short winged morphs. Additionally, females exhibited higher PO activity than males, and by contrast, males had higher lysozyme activity than females. Our study suggests that G. firmus morphs prioritize different immune responses that may reflect a balancing between the costs of immunity and differing pathogen threats. Male and female crickets exhibit differences in humoral immune responses that may reflect their different life history demands.
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Affiliation(s)
- Lucas J Kirschman
- Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL, USA.
| | - Daniel Morales
- Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Emily Crawford
- Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Anthony J Zera
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
| | - Robin W Warne
- Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL, USA
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Kirschman LJ, Crespi EJ, Warne RW. Critical disease windows shaped by stress exposure alter allocation trade‐offs between development and immunity. J Anim Ecol 2017; 87:235-246. [DOI: 10.1111/1365-2656.12778] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 10/20/2017] [Indexed: 02/06/2023]
Affiliation(s)
| | - Erica J. Crespi
- School of Biological SciencesWashington State University Pullman WA USA
| | - Robin W. Warne
- Department of ZoologySouthern Illinois University Carbondale IL USA
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Kirschman LJ, Quade AH, Zera AJ, Warne RW. Immune function trade-offs in response to parasite threats. J Insect Physiol 2017; 98:199-204. [PMID: 28109904 DOI: 10.1016/j.jinsphys.2017.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 01/11/2017] [Accepted: 01/16/2017] [Indexed: 06/06/2023]
Abstract
Immune function is often involved in physiological trade-offs because of the energetic costs of maintaining constitutive immunity and mounting responses to infection. However, immune function is a collection of discrete immunity factors and animals should allocate towards factors that combat the parasite threat with the highest fitness cost. For example, animals on dispersal fronts of expanding population may be released from density-dependent diseases. The costs of immunity, however, and life history trade-offs in general, are often context dependent. Trade-offs are often most apparent under conditions of unusually limited resources or when animals are particularly stressed, because the stress response can shift priorities. In this study we tested how humoral and cellular immune factors vary between phenotypes of a wing dimorphic cricket and how physiological stress influences these immune factors. We measured constitutive lysozyme activity, a humoral immune factor, and encapsulation response, a cellular immune factor. We also stressed the crickets with a sham predator in a full factorial design. We found that immune strategy could be explained by the selective pressures encountered by each morph and that stress decreased encapsulation, but not lysozyme activity. These results suggest a possible trade-off between humoral and cellular immunity. Given limited resources and the expense of immune factors, parasite pressures could play a key factor in maintaining insect polyphenism via disruptive selection.
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Affiliation(s)
- Lucas J Kirschman
- Department of Zoology, Southern Illinois University, Carbondale, IL, USA.
| | - Adam H Quade
- Department of Zoology, Southern Illinois University, Carbondale, IL, USA
| | - Anthony J Zera
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
| | - Robin W Warne
- Department of Zoology, Southern Illinois University, Carbondale, IL, USA
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Kirschman LJ, McCue MD, Boyles JG, Warne RW. Exogenous stress hormones alter energetic and nutrient costs of development and metamorphosis. J Exp Biol 2017; 220:3391-3397. [DOI: 10.1242/jeb.164830] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/17/2017] [Indexed: 11/20/2022]
Abstract
Variation in environmental conditions during larval life stages can shape development during critical windows and have lasting effects on the adult organism. Changes in larval developmental rates in response to environmental conditions, for example, can trade-off with growth to determine body size and condition at metamorphosis, which can affect adult survival and fecundity. However, it is unclear how use of energy and nutrients shape trade-offs across life stage transitions because no studies have quantified these costs of larval development and metamorphosis. We used an experimental approach to manipulate physiological stress in larval amphibians, along with respirometry and 13C-breath testing to quantify the energetic and nutritional costs of development and metamorphosis. Central to larval developmental responses to environmental conditions is the hypothalamus pituitary-adrenal/interrenal (HPA/I) axis, which regulates development, as well as energy homeostasis and stress responses across many taxa. Given these pleiotropic effects of HPA/I activity, manipulation of the HPA/I may provide insight into costs of metamorphosis. We measured the energetic and nutritional costs across the entire larval period and metamorphosis in a larval amphibian exposed to exogenous glucocorticoid (GC) hormones- the primary hormone secreted by the HPA/I axis. We measured metabolic rates and dry mass across larval ontogeny, and quantified lipid stores and nutrient oxidation via 13C-breath testing during metamorphosis, under control and GC-exposed conditions. Changes in dry mass match metamorphic states previously reported in the literature, but dynamics of metabolism were influenced by the transition from aquatic to terrestrial respiration. GC-treated larvae had lower dry mass, fat stores, and higher oxygen consumption during stages where controls were conserving energy. GC-treated larvae also oxidized greater amounts of 13C-labelled protein stores. These results provide evidence for a proximate cause of the physiological trade-off between larval growth and development, and provide insight into the energetic and nutrient costs that shape fitness trade-offs across life stages.
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Affiliation(s)
- Lucas J. Kirschman
- Department of Zoology, Southern Illinois University, Carbondale, IL USA, 62901
| | - Marshall D. McCue
- Department of Biological Sciences, St. Mary's University, San Antonio, TX, 78228, USA
| | - Justin G. Boyles
- Cooperative Wildlife Research Laboratory, Department of Zoology, Southern Illinois University, Carbondale, IL USA, 62901
| | - Robin W. Warne
- Department of Zoology, Southern Illinois University, Carbondale, IL USA, 62901
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Kirschman LJ, Haslett S, Fritz KA, Whiles MR, Warne RW. Influence of Physiological Stress on Nutrient Stoichiometry in Larval Amphibians. Physiol Biochem Zool 2016; 89:313-21. [DOI: 10.1086/687047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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