Fitness effects of Ty transposition in Saccharomyces cerevisiae.
Fitness effects of Ty transposition in Saccharomyces cerevisiae.
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Ty 转座对酿酒酵母的适应性影响。
DOI：
10.1093/genetics/131.1.31
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发表时间：
1992
期刊：
影响因子：
3.3
通讯作者：
Adams,J
中科院分区：
文献类型：
--
作者：
Wilke,CM;Adams,J
转座因子在进化中的主要作用是消极的和寄生的。或者，许多转座因子的靶特异性和基因调控能力提高了转座因子诱导的突变比其他类型的突变更可能适应性有利的可能性。构建了含有大量Ty 1基因组插入变异的酿酒酵母群体，并测定了Ty 1拷贝数对适应性、产量和生长速率两个组分的影响。尽管平均稳定期密度随着Ty 1拷贝数的增加而降低，但方差和范围却增加。固定相密度的分布表明，许多Ty 1插入有负面影响的健身，但也有一些可能有积极的影响。为了直接测试适应性有利的Ty 1插入，在连续培养中生长含有大量Ty 1拷贝数变异性的群体。经过98-112代后，含有零Ty 1元件的克隆的频率下降到约0.0，并且含有特定Ty 1的克隆家族占主导地位。考虑到大多数的遗传变异的人口是由于Ty 1转座，和Ty 1插入，平均而言，健身的负面影响，我们得出结论，Ty 1转座事件是直接负责生产适应性突变的克隆占主导地位的人口。
It has been suggested that the primary evolutionary role of transposable elements is negative and parasitic. Alternatively, the target specificity and gene regulatory capabilities of many transposable elements raise the possibility that transposable element-induced mutations are more likely to be adaptively favorable than other types of mutations. Populations of Saccharomyces cerevisiae containing large amounts of variation for Ty1 genomic insertions were constructed, and the effects of Ty1 copy number on two components of fitness, yield and growth rate were determined. Although mean stationary phase density decreased with increased Ty1 copy number, the variance and range increased. The distributions of stationary phase densities indicate that many Ty1 insertions have negative effects on fitness, but also that some may have positive effects. To test directly for adaptively favorable Ty1 insertions, populations containing large amounts of variability for Ty1 copy number were grown in continuous culture. After 98-112 generations the frequency of clones containing zero Ty1 elements had decreased to approximately 0.0, and specific Ty1-containing clone families had predominated. Considering that most of the genetic variation in the populations was due to Ty1 transposition, and that Ty1 insertions had, on average, a negative effect on fitness, we conclude that Ty1 transposition events were directly responsible for the production of adaptive mutations in the clones that predominated in the populations.