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Abstract When animals are sick, their physiology and behavior change in ways that can impact their offspring. Research is emerging showing that infection risk alone can also modify the physiology and behavior of healthy animals. If physiological responses to environments with high infection risk take place during reproduction, it is possible that they lead to maternal effects. Understanding whether and how high infection risk triggers maternal effects is important to elucidate how the impacts of infectious agents extend beyond infected individuals and how, in this way, they are even stronger evolutionary forces than already considered. Here, to evaluate the effects of infection risk on maternal responses, we exposed healthy female Japanese quail to either an immune-challenged (lipopolysaccharide [LPS] treated) mate or to a healthy (control) mate. We first assessed how females responded behaviorally to these treatments. Exposure to an immune-challenged or control male was immediately followed by exposure to a healthy male, to determine whether treatment affected paternity allocation. We predicted that females paired with immune-challenged males would avoid and show aggression towards those males, and that paternity would be skewed towards the healthy male. After mating, we collected eggs over a 5-day period. As an additional control, we collected eggs from immune-challenged females mated to healthy males. We tested eggs for fertilization status, embryo sex ratio, as well as albumen corticosterone, lysozyme activity, and ovotransferrin, and yolk antioxidant capacity. We predicted that immune-challenged females would show the strongest changes in the egg and embryo metrics, and that females exposed to immune-challenged males would show intermediate responses. Contrary to our predictions, we found no avoidance of immune-challenged males and no differences in terms of paternity allocation. Immune-challenged females laid fewer eggs, with an almost bimodal distribution of sex ratio for embryos. In this group, albumen ovotransferrin was the lowest, and yolk antioxidant capacity decreased over time, while it increased in the other treatments. No differences in albumen lysozyme were found. Both females that were immune-challenged and those exposed to immune-challenged males deposited progressively more corticosterone in their eggs over time, a pattern opposed to that shown by females exposed to control males. Our results suggest that egg-laying Japanese quail may be able to respond to infection risk, but that additional or prolonged sickness symptoms may be needed for more extensive maternal responses.
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The female perspective on disease risk
When faced with deteriorating conditions (such as shortage of resources, temperature extremes, or infection), females can prioritize their own survival overinvestmentinreproduction.Alternatively,itisalso possible for females to adjust the phenotype of their offspring in ways that may change how offspring cope with, and thrive under, those stressful environments. Here, I raise the possibility that the perception of dis- ease risk also triggers trade-offs between survival and reproduction in females. Mounting evidence suggests that animals can respond to disease risk. For example, the presence of a diseased groupmate can trigger changes in the behavior and physiology of animals not experiencing that disease. I will use recently published studies to illustrate how reproducing females respond both behaviorally and physiologically to high-disease- risk environments and how those responses can affect both their reproduction and the phenotype of their offspring. More research on this topic is necessary to fully comprehend the cascading effects that maternal responsestodiseaseriskmayhaveforoffspringandthe potential feedbacks of those on the mother. Given the expected rise in infectious disease events, this knowl- edge will be critical to predict how populations will respond to these upcoming challenges. My goal is that this overview and discussion will help the community arrive at a conceptual framework for understanding when parental responses to disease risk are costly or beneficialforparentsandoffspring.
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- Award ID(s):
- 2232190
- PAR ID:
- 10574385
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Integrative And Comparative Biology
- Volume:
- 64
- Issue:
- Supplement_1
- ISSN:
- 1540-7063
- Page Range / eLocation ID:
- S310 to S311
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/icb/icae140
