French Susannah S, Moore Michael C
School of Life Sciences, Arizona State University, Tempe, AZ 85287-4601, USA.
Gen Comp Endocrinol. 2008 Jan 1;155(1):148-56. doi: 10.1016/j.ygcen.2007.04.007. Epub 2007 Apr 11.
Competition among physiological processes for limited resources often results in trade-offs. Key among these processes is reproduction and immune function, and optimizing both appears to be difficult. To test the hypothesis that the resource demands of reproduction compromise immune function, we measured rates of wound healing, an integrated measure of innate immunity, across different reproductive stages in female and male tree lizards (Urosaurus ornatus) in both the field and the laboratory. The hypothesis predicted that immune function would be lowest when resource demands of reproduction are highest, i.e., vitellogenic females and reproductive males. In the field, vitellogenic females had significantly slower healing rate than females in other reproductive stages. However, in the laboratory, vitellogenic females had a healing rate similar to that of other females. Conversely, males showed suppression of healing in the laboratory but not in the field during the reproductive season. The results of this study support a trade-off between reproduction and immune function, and suggest that reproduction is given priority. However, the results also indicate that this trade-off is not fixed in the reproductive process and that it may instead be dependent on the context, sex or resource balance of the individual.
生理过程对有限资源的竞争常常导致权衡取舍。这些过程中关键的是繁殖和免疫功能,而要同时优化这两者似乎很困难。为了验证繁殖对资源的需求会损害免疫功能这一假设,我们在野外和实验室中测量了雌性和雄性西部强棱蜥(Urosaurus ornatus)在不同繁殖阶段的伤口愈合速率,这是一种对先天免疫的综合测量。该假设预测,当繁殖对资源的需求最高时,即处于卵黄生成期的雌性和繁殖期的雄性,免疫功能会最低。在野外,处于卵黄生成期的雌性的愈合速率明显低于其他繁殖阶段的雌性。然而,在实验室中,处于卵黄生成期的雌性的愈合速率与其他雌性相似。相反,在繁殖季节,雄性在实验室中表现出愈合受抑制,但在野外则没有。这项研究的结果支持了繁殖与免疫功能之间的权衡取舍,并表明繁殖具有优先性。然而,结果也表明这种权衡取舍在繁殖过程中并非固定不变,相反,它可能取决于个体的环境、性别或资源平衡。