VARIATIONS OF CANDIDA-ALBICANS ELECTROPHORETIC KARYOTYPES
VARIATIONS OF CANDIDA-ALBICANS ELECTROPHORETIC KARYOTYPES
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DOI：
10.1128/jb.173.20.6586-6596.1991
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发表时间：
1991-10-01
影响因子：
3.2
通讯作者：
RUSTCHENKOBULGAC, EP
中科院分区：
文献类型：
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作者：
RUSTCHENKOBULGAC, EP
我们以前描述了14种罕见的自发形态突变的白色念珠菌，与染色体畸变（E。P. Rustchenko-Bulgac，F.谢尔曼和J. B. Hicks，J. Bacteriol. 172：1276-1283，1990）。改良的染色体分离条件和杂交探针用于研究临床分离株和其他形态突变株的核型变异。所有23个新分析的形态突变体，代表频繁发生和高度不稳定的殖民形式，有各种改变核型。所有的染色体变化与先前在突变体M1至M14中观察到的相似。在这项研究中，我特别注意到，最频繁的变化涉及长染色体VIII，它携带核糖体DNA顺反子。通过分析两个高度不稳定突变体的后代，发现了两种不稳定率。一个不稳定的突变体被证明能够连续产生大量改变的核型，这可能导致各种不同的表型。此外，所有四个独立的临床分离株，FC 18，C9，3153 A，WO-1，常见的实验室菌株，显示不同的电泳核型和不同的殖民地形态的合成培养基上，类似于自发突变体。临床分离株间电泳核型的差异与不同类型自发形态突变株间的差异相似。这些研究结果有助于理解自然核型变异性，并与在实验室条件下自发观察到的染色体改变提供这种无融合生殖物种在自然界中具有遗传变异性的假设一致。
We previously described 14 rare spontaneous morphological mutants of Candida albicans that were associated with chromosomal aberrations (E. P. Rustchenko-Bulgac, F. Sherman, and J. B. Hicks, J. Bacteriol. 172:1276-1283, 1990). Improved conditions for separation of chromosomes, as well as hybridization probes, were used to investigate the variation of karyotypes of clinical isolates and additional morphological mutants. All 23 newly analyzed morphological mutants, representing frequently occurring and highly unstable colonial forms, had a variety of altered karyotypes. All chromosomal changes were similar to those previously observed in mutants m1 to m14. In this study, I particularly noted that the most frequent changes involved the long chromosome VIII, which carries ribosomal DNA cistrons. Two rates of instability were uncovered by analyzing the progenies from two highly unstable mutants. An unstable mutant proved to be able to continuously produce a large number of altered karyotypes that could result in a wide variety of different phenotypes. Furthermore, all four independent clinical isolates, FC18, C9, 3153A, and WO-1, common laboratory strains, revealed different electrophoretic karyotypes and distinct colonial morphologies on a synthetic medium, similar to spontaneous mutants. The differences of electrophoretic karyotypes observed among clinical isolates resembled the changes found among different kinds of spontaneous morphological mutants. These findings contribute to the understanding of natural karyotypic variability and are in agreement with the hypothesis that chromosomal alterations observed spontaneously under laboratory conditions provide this amictic species with genetic variability in nature.