Outlaw D C, Ricklefs R E
Department of Biology, University of Missouri-St. Louis, St. Louis, Missouri 63121, USA.
J Parasitol. 2009 Oct;95(5):1171-6. doi: 10.1645/GE-1982.1. Epub 2009 Mar 30.
Haemosporidian parasite diversity among raptorial birds (hawks and owls), as estimated by DNA sequencing, is proving to be greater than previously anticipated from taxonomic assessments based on parasite morphology. Here, we place raptor parasites in a phylogenetic context, including new parasite cytochrome b (cyt b) sequences from North America and Europe and from a variety of host species not previously sampled. Mitochondrial DNA sequences reveal raptor-specific parasite clades within Parahaemoproteus, but not within Plasmodium. We also recovered a strikingly divergent clade of raptor parasites that aligns with neither genus, but groups with both as a sister clade to Leucocytozoon. Different cyt b primer sets recovered additional sequences from 3 of these samples, which grouped with Parahaemoproteus in 2 cases and with Plasmodium in 1 case. Possible explanations (after excluding contamination) include multiple infections, alternative cyt b copies within the mitochondrial genome, and nuclear copies of mitochondrial genes. We believe the latter 2 explanations are unlikely because these divergent cyt b lineages form a single clade and were also recovered with several additional genomic markers.
通过DNA测序估计,猛禽(鹰和猫头鹰)体内血孢子虫寄生虫的多样性比之前基于寄生虫形态学的分类评估所预期的要高。在这里,我们将猛禽寄生虫置于系统发育背景下,包括来自北美和欧洲以及各种此前未采样宿主物种的新的寄生虫细胞色素b(cyt b)序列。线粒体DNA序列揭示了副血疟原虫属内猛禽特有的寄生虫分支,但疟原虫属内没有。我们还发现了一个与这两个属都不匹配、但与它们一起作为白细胞虫属姐妹分支的明显不同的猛禽寄生虫分支。不同的cyt b引物组从其中3个样本中获得了额外序列,其中2例与副血疟原虫属归为一类,1例与疟原虫属归为一类。(排除污染后)可能的解释包括多重感染、线粒体基因组内的替代cyt b拷贝以及线粒体基因的核拷贝。我们认为后两种解释不太可能,因为这些不同的cyt b谱系形成了一个单一的分支,并且还通过几个额外的基因组标记被发现。