Individuals vary their immune response according to age, sex and the costs

Sep 10, 2008
The sexes face differential immune investment costs as they mature from nest-bound juveniles to independent adults. Credit: Oliver P. Love

Is it always good to respond maximally when pathogens or disease strike, or should individuals vary their immune response to balance immediate and future costs? This is the question evolutionary physiologists Oliver Love, Katrina Salvante, James Dale, and Tony Williams asked when they examined how a simple immune response varied at different life stages across the life-span of individual zebra finches (Taeniopygia guttata), in a study published in the September issue of the American Naturalist.

When transitioning from nest-bound juveniles to adults, female immune responses matured slowly whereas males showed dramatic variation potentially due to the costs of molting into their colorful sexually dimorphic plumage. Adult males showed little variation in immune response despite changes in resource quality.

Likewise, when females laid eggs under high-quality resource conditions, immune responses were also consistent with those during non-breeding and similar to male responses. However, when laying on reduced resources females reduced their immune response and their reproductive output consistent with a facultative (resource-driven) effect of reproductive effort on immunity.

Moreover, even under high-resource conditions during the chick-rearing stage mothers showed reduced immune responses compared to fathers suggesting a residual energetic cost of egg-laying. Perhaps most importantly, immune responses of juveniles of both sexes did not predict their subsequent adult responses.

Immune responses of adult females were only predictable when the quality of the environment remained constant; as soon as conditions deteriorated, individual females required flexibility in both the immune and reproductive systems. However, the degree of flexibility came at a cost as only individuals with high immune responses as non-breeders had the capacity to reduce responses when times became tough.

These results underlie the fact that immunity is a highly plastic trait that can be modulated in a sex- and context-dependent manner. Given the need for individual flexibility in the immune system, this suggests that an immune response at one stage may provide limited information about immune response at future stages.

Citation: Oliver P. Love, Katrina G. Salvante, James Dale, and Tony D. Williams, "Sex-specific variability in the immune system across life-history stages." American Naturalist (2008) 172: E99–E112

Source: University of Chicago

Explore further: From dandruff to deep sea vents, an ecologically hyper-diverse fungus

add to favorites email to friend print save as pdf

Related Stories

Is anyone immune to the social media echo chamber?

Aug 13, 2014

It's becoming increasingly obvious that as we spend more time communicating via social media, we are disappearing into bubbles. We receive information from the same sources and witness the views of the same ...

Foiling bugs that foil drugs

Aug 12, 2014

Every week, faculty members in the department of chemistry meet over lunch to discuss current literature in the field. The conversation at one of these meetings led Marcos Pires to what he calls a "crazy ...

Genetics reveal effects of deadly frog fungus

Aug 07, 2014

(Phys.org) —A deadly fungus has decimated certain populations of amphibians globally for the past few decades, but scientists remain unclear about the exact mechanisms that lead to its disease.

Recommended for you

Of bees, mites, and viruses

11 minutes ago

Honeybee colonies are dying at alarming rates worldwide. A variety of factors have been proposed to explain their decline, but the exact cause—and how bees can be saved—remains unclear. An article published on August ...

Canola flowers faster with heat genes

2 hours ago

(Phys.org) —A problem that has puzzled canola breeders for years has been solved by researchers from The University of Western Australia - and the results could provide a vital breakthrough in understanding ...

User comments : 0