Immune challenge retards seasonal reproductive regression in rodents: evidence for terminal investment.
Immune challenge retards seasonal reproductive regression in rodents: evidence for terminal investment.
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免疫挑战延缓啮齿类动物的季节性生殖衰退：终端投资的证据。
DOI：
10.1098/rsbl.2006.0475
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发表时间：
2006
期刊：
影响因子：
3.3
通讯作者：
Nelson,RandyJ
中科院分区：
文献类型：
--
作者：
Weil,ZacharyM;Martin,LynnB;Workman,JoannaL;Nelson,RandyJ
动物必须在不同的生理活动中平衡投资，使它们能够最大限度地适应它们所居住的环境。这些在繁殖、生长和生存之间的调整是强制性的，因为每个过程的竞争成本都很高。当环境条件良好时，季节性繁殖的啮齿动物的投资通常倾向于繁殖，但当环境条件恶化时，这些投资将转向促进生存的过程，包括免疫活动。由于非热带小型哺乳动物在冬季的生存概率普遍较低，在某些情况下，这些动物可能不会将资源分配给生存机制，以在死亡概率增加的情况下努力产生尽可能多的后代。这种“终端投资”已经在雀形目动物中被描述过，但在小型哺乳动物中很少有这种现象的例子。在这里，我们发现雄性西伯利亚仓鼠（Phodopus sungorus）受到脂多糖（一种激活免疫系统的革兰氏阴性菌成分）的刺激，相对于注射了盐的仓鼠，生殖系统的季节性回归出现了轻微但显著的延迟。这种延迟的生殖退化可能反映了当生存前景受到感染时维持生殖功能的策略。
Animals must balance investments in different physiological activities to allow them to maximize fitness in the environments they inhabit. These adjustments among reproduction, growth and survival are mandated because of the competing high costs of each process. Seasonally breeding rodents generally bias their investments towards reproduction when environmental conditions are benign, but shift these investments towards processes that promote survival, including immune activity, when environmental conditions deteriorate. Because survival probability of non-tropical small mammals is generally low in winter, under certain circumstances, these animals may not allocate resources to survival mechanisms in an effort to produce as many offspring as possible in the face of increased probability of death. Such ‘terminal investments’ have been described in passerines, but there are few examples of such phenomena in small mammals. Here, we show that male Siberian hamsters (Phodopus sungorus) challenged with lipopolysaccharide (a component of gram-negative bacteria that activates the immune system) induced a small, but significant, retardation of seasonal regression of the reproductive system relative to saline-injected hamsters. This delayed reproductive regression likely reflects a strategy to maintain reproductive function when survival prospects are compromised by infection.