Regulated polyploidy in halophilic archaea.
Regulated polyploidy in halophilic archaea.
复制标题
嗜盐古菌中受调控的多倍体。
DOI：
10.1371/journal.pone.0000092
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发表时间：
2006-12-20
期刊：
影响因子：
3.7
通讯作者：
Soppa J
中科院分区：
文献类型：
--
作者：
Breuert S;Allers T;Spohn G;Soppa J
多倍体在高等真核生物中很常见，尤其是在植物中，但通常认为大多数原核生物含有一个环状染色体的单拷贝，因此是单倍体。我们使用了两种独立的方法来确定嗜盐古菌的基因组拷贝数，1）琼脂糖块中的细胞裂解和Southern印迹分析，以及2）实时定量PCR。快速生长的H.盐藻细胞在指数期平均含有约25个拷贝的染色体，在早期稳定期其倍性下调至15个拷贝。染色体拷贝数是相同的文化与低两倍的增长率，在几个其他原核生物物种的结果报告相反。三个额外的复制子的H。salinarum中，两个具有不受生长期调节的低拷贝数，而一个复制子甚至显示出比主复制子更高程度的生长期依赖性调节。H. volcanii在指数期也类似地高（平均18个拷贝/细胞），并且当细胞进入稳定期时也下调（至10个拷贝）。群体中基因组拷贝数的变化通过荧光显微镜和FACS分析来解决。这些方法使我们能够验证H. salinarum，并且他们揭示了个体细胞中基因组拷贝数的广泛变化，其在指数期比在稳定期大得多。我们的研究结果表明，多倍性可能是更广泛的古菌（甚至原核生物一般）比以前假设的。此外，原核生物中如此多的基因组拷贝的存在引发了关于这种策略的进化意义的问题。
Polyploidy is common in higher eukaryotes, especially in plants, but it is generally assumed that most prokaryotes contain a single copy of a circular chromosome and are therefore monoploid. We have used two independent methods to determine the genome copy number in halophilic archaea, 1) cell lysis in agarose blocks and Southern blot analysis, and 2) Real-Time quantitative PCR. Fast growing H. salinarum cells contain on average about 25 copies of the chromosome in exponential phase, and their ploidy is downregulated to 15 copies in early stationary phase. The chromosome copy number is identical in cultures with a twofold lower growth rate, in contrast to the results reported for several other prokaryotic species. Of three additional replicons of H. salinarum, two have a low copy number that is not growth-phase regulated, while one replicon even shows a higher degree of growth phase-dependent regulation than the main replicon. The genome copy number of H. volcanii is similarly high during exponential phase (on average 18 copies/cell), and it is also downregulated (to 10 copies) as the cells enter stationary phase. The variation of genome copy numbers in the population was addressed by fluorescence microscopy and by FACS analysis. These methods allowed us to verify the growth phase-dependent regulation of ploidy in H. salinarum, and they revealed that there is a wide variation in genome copy numbers in individual cells that is much larger in exponential than in stationary phase. Our results indicate that polyploidy might be more widespread in archaea (or even prokaryotes in general) than previously assumed. Moreover, the presence of so many genome copies in a prokaryote raises questions about the evolutionary significance of this strategy.
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影响因子：
3.4
作者：
CHANT, J;HUI, I;DENNIS, PP
通讯作者：
DENNIS, PP
影响因子：
4.4
作者：
Hiraoka, Y;Yamada, T;Kimbara, K
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Kimbara, K
影响因子：
3.9
作者：
Liao, DQ
通讯作者：
Liao, DQ
影响因子：
3.6
作者：
Maisnier-Patin, S;Malandrin, L;Bernander, R
通讯作者：
Bernander, R
影响因子：
3.2
作者：
MALDONADO, R;JIMENEZ, J;CASADESUS, J
通讯作者：
CASADESUS, J