Why is the genome variable? Insights from Drosophila.
Why is the genome variable? Insights from Drosophila.
复制标题
为什么基因组是可变的？
DOI：
10.1016/0168-9525(92)90281-8
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Aquadro,CF
中科院分区：
文献类型：
--
作者：
Aquadro,CF
理解进化的基础是关于种群中遗传变异的数量和性质以及为什么存在这种变异的信息。特别是在20世纪40年代和50年代，关于自然群体的遗传变异水平存在相当大的争论，其中一个学派假设由于存在一个最佳基因型，遗传变异非常小，另一种则提出了由自然选择维持的广泛的遗传变异。到了20世纪60年代，这场争论仍然没有解决，因为无法以公正的方式对单个基因进行变异分析。蛋白质电泳的引入清楚地表明，果蝇，人类和其他生物体中的许多蛋白质编码基因存在广泛的变异。争论转向了这些基因在多大程度上准确地反映了潜在的平均基因组变异，以及为什么这种广泛的变异存在于某些基因而不是其他基因。在果蝇和许多其他生物体中观察到的几种酶的等位酶变异的空间和时间模式表明，自然选择维持了蛋白质多态性。然而，蛋白质电泳只能检测到一部分潜在的DNA变异，并且只能提供关于变异频率的信息，任何特定的变异分布通常都与几种替代假设相一致，包括自然选择、偶然或最近的进化史（例如种群扩张或混合）。估计或确定任何感兴趣的基因组区域中和周围的DNA序列变异的能力已经开辟了一种新的实验和生物学方法。
Fundamental to an understanding of evolution is information about the amount and nature of genetic variation in populations and why such variation exists. During the 1940s and 1950s in particular, there was considerable debate about the level of genetic variation in natural populations, with one school of thought hypothesizing very little genetic variability due to the presence of one best genotype, and the other proposing extensive genetic variation maintained by natural selectionL Until the mid-1960s this debate remained unresolved because single genes could not be assayed in an unbiased way for variation. The introduction of protein electrophoresis demonstrated clearly for Drosophila, humans and other organisms that there was extensive variation in many protein-coding genes 1. The debate shifted to asking to what extent these genes accurately reflected underlying average genomic variability, and why this extensive variation existed for some genes and not for others. Spatial and temporal patterns of allozyme variation that have been observed for several enzymes in Drosophila and many other organisms suggest that natural selection maintains protein polymorphism 1. However, protein electrophoresis detects only a portion of underlying DNA variation and provides information only on frequencies of variants, any specific distribution of which is often consistent with several alternative hypotheses including natural selection, chance or recent evolutionary history (eg population expansion or mixture). The ability to estimate or determine the DNA sequence variation in and around any genomic region of interest has opened up a new experimental and