Weeks Andrew R, Hoffmann Ary A
Centre for Environmental Stress and Adaptation Research, Department of Genetics, University of Melbourne, Parkville, Victoria 3010, Australia.
Proc Natl Acad Sci U S A. 2008 Nov 18;105(46):17872-7. doi: 10.1073/pnas.0806039105. Epub 2008 Nov 12.
Asexual organisms can be genetically variable and evolve through time, yet it is not known how genetic diversity is maintained in populations. In sexual organisms, negative frequency-dependent selection plays a role in maintaining diversity at some loci, but in asexual organisms, this mechanism could provide a general explanation for persistent genetic diversity because it acts on the whole genome and not just on some polymorphisms within a genome. Using field manipulations, we show that negative frequency-dependent selection maintains clonal diversity in an asexual mite species, and we link predicted equilibrium clonal frequencies to average frequencies in space and time. Intense frequency-dependent selection is likely to be a general mechanism for persistent genetic diversity in asexual organisms.
无性生物可以在基因上具有变异性并随时间进化，但目前尚不清楚种群中的遗传多样性是如何维持的。在有性生物中，负频率依赖选择在维持某些基因座的多样性方面发挥作用，但在无性生物中，这种机制可以为持续的遗传多样性提供一个普遍的解释，因为它作用于整个基因组，而不仅仅是基因组内的一些多态性。通过田间操作，我们表明负频率依赖选择维持了一种无性螨虫物种的克隆多样性，并且我们将预测的平衡克隆频率与空间和时间上的平均频率联系起来。强烈的频率依赖选择可能是无性生物中持续遗传多样性的一个普遍机制。
