Wood Matthew J, Cosgrove Catherine L, Wilkin Teddy A, Knowles Sarah C L, Day Karen P, Sheldon Ben C
Edward Grey Institute, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
Mol Ecol. 2007 Aug;16(15):3263-73. doi: 10.1111/j.1365-294X.2007.03362.x.
The development of molecular genetic screening techniques for avian blood parasites has revealed many novel aspects of their ecology, including greatly elevated diversity and complex host-parasite relationships. Many previous studies of malaria in birds have treated single study populations as spatially homogeneous with respect to the likelihood of transmission of malaria to hosts, and we have very little idea whether any spatial heterogeneity influences different malaria lineages similarly. Here, we report an analysis of variation in the prevalence and cytochrome b lineage distribution of avian malaria infection with respect to environmental and host factors, and their interactions, in a single blue tit (Cyanistes caeruleus) population. Of 11 Plasmodium and Haemoproteus cytochrome b lineages found in 997 breeding individuals, the three most numerous (pSGS1, pTURDUS1 and pBT7) were considered separately, in addition to analyses of all avian malaria lineages pooled. Our analyses revealed marked spatial differences in the prevalence and distribution of these lineages, with local prevalence of malaria within the population ranging from over 60% to less than 10%. In addition, we found several more complex patterns of prevalence with respect to local landscape features, host state, parasite genotype, and their interactions. We discuss the implications of such heterogeneity in parasite infection at a local scale for the study of the ecology and evolution of infectious diseases in natural populations. The increased resolution afforded by the combination of molecular genetic and geographical information systems (GIS) tools has the potential to provide many insights into the epidemiology, evolution and ecology of these parasites in the future.
用于鸟类血液寄生虫的分子遗传筛查技术的发展揭示了其生态学的许多新方面，包括多样性大幅提高以及复杂的宿主-寄生虫关系。以前许多关于鸟类疟疾的研究都将单一研究种群在疟疾传播给宿主的可能性方面视为空间同质的，而我们对于任何空间异质性是否以类似方式影响不同的疟疾谱系知之甚少。在此，我们报告了对一个单一蓝山雀（Cyanistes caeruleus）种群中鸟类疟疾感染的患病率和细胞色素b谱系分布相对于环境和宿主因素及其相互作用的变异分析。在997只繁殖个体中发现的11种疟原虫和血变原虫细胞色素b谱系中，除了对所有合并的鸟类疟疾谱系进行分析外，还分别考虑了数量最多的三个谱系（pSGS1、pTURDUS1和pBT7）。我们的分析揭示了这些谱系在患病率和分布上的显著空间差异，种群内疟疾的局部患病率从超过60%到不到10%不等。此外，我们还发现了一些关于局部景观特征、宿主状态、寄生虫基因型及其相互作用的更为复杂的患病率模式。我们讨论了这种局部尺度上寄生虫感染的异质性对自然种群中传染病生态学和进化研究的影响。分子遗传学和地理信息系统（GIS）工具相结合所提供的更高分辨率有可能在未来为这些寄生虫的流行病学、进化和生态学提供许多见解。
