Pap Péter László, Vágási Csongor István, Czirják Gábor Arpád, Titilincu Adriana, Pintea Adela, Barta Zoltán
Behavioural Ecology Research Group, Department of Evolutionary Zoology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary.
J Exp Biol. 2009 Oct;212(Pt 20):3228-35. doi: 10.1242/jeb.031948.
In the present study, we experimentally manipulated coccidian parasitism and dietary carotenoid availability in a fully factorial experiment in male house sparrows (Passer domesticus Linnaeus), and tested whether carotenoid supplementation reduces the cost of parasitism in terms of condition, moult and immune responses. We found that coccidians have a significant but transient negative effect on body mass, which can be reduced if birds have access to carotenoid supplementation in their diet. Experimental manipulation had no significant effect on the moulting parameters of the birds measured following coccidian infestation and during the whole moulting period. Carotenoid supplementation increased the plasma carotenoid concentration in both infested and medicated birds treated with a coccidiostatic drug; however, after two months exposure to parasites, plasma carotenoid concentration increased only in the carotenoid-supplemented and medicated group whereas no difference was observed between the carotenoid-supplemented and infested and non-supplemented groups. On the contrary, coccidian infestation was not affected by carotenoid supplementation. Experimental infestation decreased the antibody response to sheep red blood cells (SRBCs), although no significant effect was observed in the capacity of the birds to respond to a mitogenic challenge with phytohemagglutinin. Within the experimentally infested groups birds with carotenoid-supplemented food tended to have an increased anti-SRBC humoral immune response. The positive correlation between coccidian infestation and the strength of the humoral immune response against SRBCs in the non-supplemented and infested groups indicates that this part of the immune system plays an important role in defence against these parasites.
在本研究中，我们在雄性家麻雀（Passer domesticus Linnaeus）的全因子实验中，通过实验操纵球虫寄生和饮食中类胡萝卜素的可获得性，并测试了补充类胡萝卜素是否能在身体状况、换羽和免疫反应方面降低寄生成本。我们发现，球虫对体重有显著但短暂的负面影响，如果鸟类在饮食中能够获得类胡萝卜素补充剂，这种影响可以减轻。实验操纵对球虫感染后及整个换羽期所测量的鸟类换羽参数没有显著影响。补充类胡萝卜素增加了用抗球虫药治疗的受感染和用药鸟类的血浆类胡萝卜素浓度；然而，在接触寄生虫两个月后，血浆类胡萝卜素浓度仅在补充类胡萝卜素且用药的组中增加，而在补充类胡萝卜素且受感染组与未补充组之间未观察到差异。相反，球虫感染不受类胡萝卜素补充的影响。实验性感染降低了对绵羊红细胞（SRBCs）的抗体反应，尽管在鸟类对植物血凝素促有丝分裂刺激的反应能力方面未观察到显著影响。在实验感染组中，食用补充类胡萝卜素食物的鸟类对SRBC的体液免疫反应往往有所增强。在未补充且受感染的组中，球虫感染与针对SRBC的体液免疫反应强度之间的正相关表明，免疫系统的这一部分在抵御这些寄生虫方面起着重要作用。
