Acute virulence in mice is associated with markers on chromosome VIII in Toxoplasma gondii
Acute virulence in mice is associated with markers on chromosome VIII in Toxoplasma gondii
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DOI：
10.1128/iai.64.12.5193-5198.1996
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发表时间：
1996-12-01
影响因子：
3.1
通讯作者：
Sibley, LD
中科院分区：
文献类型：
--
作者：
Howe, DK;Summers, BC;Sibley, LD
刚地弓形虫具有一个由三个广泛分布的克隆谱系组成的不寻常的种群结构。小鼠急性毒力在I型菌株中严格观察到，表明该谱系特有的遗传决定因素控制急性发病机制。我们分析了几种天然存在的弓形虫重组菌株，其SAG 1位点携带等位基因1;该等位基因是I型菌株的特征，先前发现与急性毒力表型100%相关。重组菌株G622-M和ROD均具有主要的III型基因型，SAG 1位点的等位基因1具有显著的例外。虽然这两种菌株具有几乎相同的多位点基因型，但它们在小鼠中的毒力不同。ROD株为强毒株，而G622-M株为无毒株，表明SAG 1的等位基因1不足以单独产生急性毒力。SAG 1上游的几个序列多态性与急性毒力谱系高度相关。总的来说，这些结果表明，急性毒力是由一个区域与SAG 1基因座上的染色体VIII在T。刚地。
Toxoplasma gondii has an unusual population structure consisting of three widely distributed clonal lineages. Acute virulence in mice is strictly observed in type I strains, indicating that a genetic determinant(s) unique to this lineage controls acute pathogenesis, We have analyzed several naturally occurring recombinant strains of T, gondii that carry allele 1 at the SAG1 locus; this allele is characteristic of the type I strains and was previously found to be 100% correlated with the acute virulence phenotype. Recombinant strains G622-M and ROD both had a predominantly type III genotype, with the significant exception of allele 1 at the SAG1 locus. Although these two strains had virtually identical multilocus genotypes, they differed in their virulence in mice. Strain ROD was virulent whereas strain G622-M was nonvirulent, thus demonstrating that the presence of allele 1 at SAG1 is not alone sufficient to confer acute virulence, Several sequence polymorphisms upstream of SAG1 were found to be highly correlated with the acutely virulent lineages. Collectively, these results suggest that acute virulence is regulated by a region linked to the SAG1 locus on chromosome VIII in T. gondii.