Data from: Adaptive landscape genetics and malaria across divergent island bird populations

Environmental conditions play a major role in shaping the spatial
distributions of pathogens, which in turn can drive local adaptation and
divergence in host genetic diversity. Haemosporidians, such as plasmodium
(malaria) are a strong selective force, impacting survival and fitness of
hosts, with geographic distributions largely determined by habitat
suitability for their insect vectors. Here, we have tested whether
patterns of fine-scale local adaptation to malaria are replicated across
discrete, ecologically differing island populations of Berthelot's
pipits Anthus berthelotii. We sequenced TLR4, an innate immunity gene that
is potentially under positive selection in Berthelot's pipits, and
two SNPs previously identified as being associated with malaria infection
in a genome-wide association study (GWAS) in Berthelot's pipits in
the Canary Islands. We determined the environmental predictors of malaria
infection, using these to estimate variation in malaria risk on Porto
Santo, and found some congruence with previously identified environmental
risk factors on Tenerife. We also found a negative association between
malaria infection and a TLR4 variant in Tenerife. In contrast, one of the
GWAS SNPs showed an association with malaria risk in Porto Santo, but in
the opposite direction to that found in the Canary Islands GWAS. Together,
these findings suggest that disease-driven local adaptation may be an
important factor in shaping variation among island populations.

环境条件在塑造病原体的空间分布中起着关键作用，而病原体的空间分布又会推动宿主的局部适应及遗传多样性分化。血孢子虫（Haemosporidians）——如疟原虫（Plasmodium，疟疾病原体）——是一种强大的选择压力，会影响宿主的生存与适合度，其地理分布在很大程度上取决于其昆虫媒介的栖息地适宜性。本研究旨在验证贝氏鹨（Berthelot's pipits, Anthus berthelotii）对疟疾的精细尺度局部适应模式是否在其离散且生态差异显著的岛屿种群中重复出现。我们对TLR4基因（一种在贝氏鹨中可能受正选择的先天免疫基因）以及两个单核苷酸多态性（SNPs）进行了测序；这两个SNPs此前在加那利群岛贝氏鹨的全基因组关联研究（GWAS）中被发现与疟疾感染相关。我们确定了疟疾感染的环境预测因子，并利用这些因子估算了圣港岛（Porto Santo）的疟疾风险变化，发现其与此前在特内里费岛（Tenerife）鉴定出的环境风险因素存在一定一致性。相比之下，其中一个GWAS鉴定的SNPs在圣港岛与疟疾风险相关，但关联方向与加那利群岛GWAS的结果相反。综上，这些发现表明，疾病驱动的局部适应可能是塑造岛屿种群间变异的重要因素。