Quantifying variation in gene expression
Quantifying variation in gene expression
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DOI：
10.1111/j.1365-294x.2007.03354.x
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发表时间：
2007-07-01
影响因子：
4.9
通讯作者：
Townsend, Jeffrey P.
中科院分区：
文献类型：
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作者：
Clark, Travis A.;Townsend, Jeffrey P.
在对物种内部和物种间基因表达变异的回顾中，Whitehead & Crawford (2006b) 引用了我们其中一位部分撰写的两项研究，提出了一个极其突出的观点。这两项研究考察了酿酒酵母单一杂合天然分离株的减数分裂后代之间的变异（Cavalieri 等人，2000 年）和酿酒酵母葡萄园种群个体之间的变异（Townsend 等人，2003 年）。正如怀特黑德和克劳福德所指出的，这两项研究揭示了类群内表达可变的基因比例相似，这一结果可能令人惊讶，因为“人们预计分离株之间差异表达的基因比例比单个菌株后代之间的差异表达基因比例更大”。然而，有两个原因可以解释为什么人们可能不会想到这一点：一个是微不足道的，另一个是极其重要的。人们预计 Cavalieri 等人（2000）检查的后代之间存在大量变异的一个微不足道的原因是，分离株不是从群体中随机采样的，而是明确选择的，因为后代分离出一种引人注目的花丝菌落形态表型，这种表型先验可能对基因组表达谱产生多种影响。相比之下，Townsend 等人（2003）的种群分离株均具有野生型菌落形态。
In their review of variation within and among species in gene expression, Whitehead & Crawford (2006b) reference two studies authored in part by one of us to make an extremely salient point. The two studies examined variation between meiotic progeny of a single heterozygous natural isolate of Saccharomyces cerevisiae (Cavalieri et al.2000) and variation among individuals from a vineyard population of S. cerevisiae (Townsend et al. 2003). As pointed out by Whitehead and Crawford, the two studies revealed a similar proportion of genes variable in expression within taxa, a result that may be surprising as ‘one would expect a greater proportion of genes differentially expressed among isolates than among progeny of a single strain’.There are, however, two reasons why one might not expect this: one trivial, and one extremely important. The trivial reason why one would expect a great deal of variation between the progeny examined in Cavalieri et al.(2000) was that the isolate was not sampled at random from a population, but rather chosen explicitly because the progeny segregate for a striking filigreed colony morphology phenotype that a priori was likely to have manifold effects upon genomic expression profile. In contrast, the population isolates of Townsend et al.(2003) all have wild type colony morphology.