Genome size, complexity, and ploidy of the pathogenic fungus Histoplasma capsulatum
Genome size, complexity, and ploidy of the pathogenic fungus Histoplasma capsulatum
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DOI：
10.1128/jb.180.24.6697-6703.1998
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发表时间：
1998-12-01
影响因子：
3.2
通讯作者：
Shearer, G
中科院分区：
文献类型：
--
作者：
Carr, J;Shearer, G
采用DNA恢复动力学、基因组重建和细胞计数技术对二态致病性真菌荚膜组织浆的基因组大小、复杂性和倍性进行了分析。从G186AS和Downs两株菌株中分离出细胞核DNA，并利用三个假定的单拷贝基因（钙调蛋白、α -微管蛋白和β -微管蛋白）进行了恢复动力学和基因组重建分析。发现G186AS的基因组约为2.3 x 10(7) bp，重复序列少于0.5%。然而，唐斯菌株的基因组大约大40%，重复DNA多16倍以上。测定唐氏病基因组大小为3.2 × 10(7) bp，重复DNA约占8%。为了确定倍性，流式细胞术测量的每个细胞的DNA质量与基因组估计值进行比较，以产生DNA指数（每个细胞的DNA /1n基因组大小）。菌株G186AS的DNA指数为0.96，Downs的DNA指数为0.94，表明两株菌株均为单倍体。利用α -微管蛋白和β -微管蛋白探针获得的基因组重建和Southern blot数据表明，唐氏菌株存在遗传重复，可能为非整倍体或部分二倍体。
The genome size, complexity, and ploidy of the dimorphic pathogenic fungus Histoplasma capsulatum was determined by using DNA renaturation kinetics, genomic reconstruction, and how cytometry, Nuclear DNA was isolated from two strains, G186AS and Downs, and analyzed by renaturation kinetics and genomic reconstruction with three putative single-copy genes (calmodulin, alpha-tubulin, and beta-tubulin), G186AS was found to have a genome of approximately 2.3 x 10(7) bp with less than 0.5% repetitive sequences. The Downs strain, however, was found to have a genome approximately 40% larger with more than 16 times more repetitive DNA. The Downs genome was determined to be 3.2 x 10(7) bp with approximately 8% repetitive DNA. To determine ploidy, the DNA mass per cell measured by flow cytometry was compared with the In genome estimate to yield a DNA index (DNA per cell/1n genome size). Strain G186AS was found to have a DNA index of 0.96, and Downs had a DNA index of 0.94, indicating that both strains are haploid. Genomic reconstruction and Southern blot data obtained with alpha- and beta-tubulin probes indicated that some genetic duplication has occurred in the Downs strain, which may be aneuploid or partially diploid.