Immune-system activation depletes retinal carotenoids in house finches (Carpodacus mexicanus).
نویسندگان
چکیده
The costs of developing, maintaining, and activating the immune system have been cited as an important force shaping life-history evolution in animals. Immunological defenses require energy, nutrients and time that might otherwise be devoted to other life-history traits like sexual displays or reproduction. Carotenoid pigments in animals provide a unique opportunity to track the costs of immune activation, because they are diet-derived, modulate the immune system, and are used to develop colorful signals of quality. Carotenoids also accumulate in the retinas of birds, where they tune spectral sensitivity and provide photoprotection. If carotenoid accumulation in the retina follows the patterns of other tissues, then immune activation may deplete retinal carotenoid levels and impact visual health and function. To test this hypothesis, we challenged molting wild-caught captive house finches (Carpodacus mexicanus) with weekly injections of lipopolysaccharide (LPS) and phytohaemagglutinin (PHA) over the course of 8 weeks. Immunostimulated adult males and females produced significant antibody responses and molted more slowly than uninjected control birds. After 8 weeks, immune-challenged birds had significantly lower levels of specific retinal carotenoid types (galloxanthin and zeaxanthin), but there were no significant differences in the plasma, liver or feather carotenoid levels between the treatment groups. These results indicate that immune-system activation can specifically deplete retinal carotenoids, which may compromise visual health and performance and represent an additional somatic and behavioral cost of immunity.
منابع مشابه
Seasonal, sexual, and quality related variation in retinal carotenoid accumulation in the house finch (Carpodacus mexicanus)
1. Studies of visual ecology generally focus on the tuning of the eye to the spectral environment. However, the environment may also shape vision if the availability of nutrients or other extrinsic stressors impact eye structure or function. 2. Carotenoids are diet-derived pigments that accumulate in the retinas of birds, where they provide photoprotection and tune colour vision. In domesticate...
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ورودعنوان ژورنال:
- The Journal of experimental biology
دوره 213 Pt 10 شماره
صفحات -
تاریخ انتشار 2010