Carton Y, Nappi A J, Poirie M
Laboratoire Populations, Génétique et Evolution, CNRS, 91198 Gif, Yvette, France.
Dev Comp Immunol. 2005;29(1):9-32. doi: 10.1016/j.dci.2004.05.004.
This review summarizes and compares available data on genetic and molecular aspects of resistance in four well-described invertebrate host-parasite systems: snail-schistosome, mosquito-malaria, mosquito-filarial worm, and Drosophila-wasp associations. It underlies that the major components of the immune reaction, such as hemocyte proliferation and/or activation, and production of cytotoxic radicals are common to invertebrate hosts. Identifying genes responsible for naturally occurring resistance will then be helpful to understand the mechanisms of invertebrate immune defenses and to determine how virulence factors are used by parasites to overcome host resistance. Based on these four well-studied models, invertebrate resistance appears as generally determined by one major locus or a few loci, displaying at least partial dominance. Interestingly, specificity of resistance is highly variable and would involve processes other than simple recognition mechanisms. Finally, resistance was shown to be generally costly but is nevertheless observed at high frequencies in many natural populations, suggesting a high potential for host parasite coevolution.
本综述总结并比较了四个描述详尽的无脊椎动物宿主 - 寄生虫系统中有关抗性的遗传和分子方面的现有数据：蜗牛 - 血吸虫、蚊子 - 疟疾、蚊子 - 丝虫以及果蝇 - 黄蜂组合。研究表明，免疫反应的主要组成部分，如血细胞增殖和/或激活以及细胞毒性自由基的产生，在无脊椎动物宿主中是常见的。鉴定负责天然抗性的基因将有助于理解无脊椎动物免疫防御机制，并确定寄生虫如何利用毒力因子来克服宿主抗性。基于这四个深入研究的模型，无脊椎动物的抗性似乎通常由一个主要基因座或几个基因座决定，表现出至少部分显性。有趣的是，抗性的特异性变化很大，可能涉及简单识别机制以外的过程。最后，研究表明抗性通常代价高昂，但在许多自然种群中仍以高频率观察到，这表明宿主 - 寄生虫共同进化具有很大潜力。
