Data from: "Blood transcriptome sequencing of Common Crossbills (Loxia curvirostra) experimentally infected by the avian malaria parasite Plasmodium relictum (lineage SGS1)" in Genomic Resources Notes accepted 1 June 2013-31 July 2013

In order to understand the epidemiology of this avian malaria infections both geographically and across host species there is a need of more polymorphic markers and knowledge about genes expressed during the infection of the host. However, technical difficulties have hindered the development of such molecular markers. The main difficulty is the fact that the host (birds) has nucleated erythrocytes and there is a 52-fold difference in the genome size between the host and the parasite. This has caused problems in trying to isolate and amplify novel nuclear genes of the avian malaria parasites. In order to overcome this difficulty and gain molecular data on nuclear genes we have sequenced blood transcriptomes of common crossbills experimentally infected with Plasmodium relictum SGS1 lineage. During development in the blood, the parasite undergoes several cycles of asexual development (erythrocytic merogony) and is invading numerous host cells and thus is expected to have a high level of gene expression. This data will serve as a resource for researchers interested in developing more molecular markers and investigating genes expressed during the erythrocytic development of avian malaria parasite. With this data we hope to take the first step into the understanding of the mechanism behind the exhibited host generalism as well as understanding how different avian malaria lineages have spread around the globe.

为从地理分布与宿主物种两个维度解析禽疟（avian malaria）感染的流行病学特征，亟需开发更多多态性分子标记，并明确宿主感染过程中表达的相关基因。然而，技术难题阻碍了此类分子标记的开发进程。核心瓶颈在于宿主（鸟类）拥有有核红细胞，且宿主与寄生虫的基因组大小相差52倍，这使得分离、扩增禽疟原虫的新型核基因面临重重阻碍。为克服该难题并获取禽疟原虫核基因的分子数据，本研究对经实验感染了里氏疟原虫（Plasmodium relictum）SGS1株系的普通交嘴雀血液转录组进行了测序。在血液发育阶段，该寄生虫会经历多轮无性发育，即红细胞内裂殖生殖（erythrocytic merogony），并侵染大量宿主细胞，因此其基因表达水平预计较高。本数据集将为致力于开发更多分子标记、探究禽疟原虫红细胞发育阶段表达基因的科研人员提供宝贵资源。借助该数据集，我们希望能够迈出解析该寄生虫表现出宿主广谱性背后机制的第一步，并阐明不同禽疟原虫株系在全球范围内的传播规律。