THE ECOLOGY AND GENETICS OF FITNESS IN CHLAMYDOMONAS. VIII. THE DYNAMICS OF ADAPTATION TO NOVEL ENVIRONMENTS AFTER A SINGLE EPISODE OF SEX
THE ECOLOGY AND GENETICS OF FITNESS IN CHLAMYDOMONAS. VIII. THE DYNAMICS OF ADAPTATION TO NOVEL ENVIRONMENTS AFTER A SINGLE EPISODE OF SEX
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衣藻健康的生态学和遗传学。
DOI：
10.1111/j.0014-3820.2002.tb00845.x
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
G. Bell
中科院分区：
文献类型：
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作者：
N. Colegrave;O. Kaltz;G. Bell
根据经典进化理论，有性重组可以产生适应环境变化所必需的变异，从而赋予有性生殖优于无性生殖的进化优势。以绿色为实验材料，研究了单次有性行为对异养生长适应不同碳源的影响。在最初的混合物的分离物，性别诱导和由此产生的后代构成有性群体，沿着任何未交配的营养细胞;未交配的混合物的分离物代表无性群体。分割率的平均值和方差（即，适合度）在黑暗中对四种碳源的所有可能的组合在大约50代营养生长期间测量四次。与连锁不平衡中上位基因重组的影响一致，有性种群最初在适应性上有较高的方差，但它们的平均适应性低于无性种群，可能是由于重组负荷。随后，有性种群的适应度超过了无性种群，但最终它们在适应度的均值和方差上都恢复了平衡。虽然重组不是更有效的更复杂的基板，这些结果一般支持的想法，性别可以加速适应新的环境。通讯编辑：T.卡瓦基
Abstract According to classical evolutionary theory, sexual recombination can generate the variation necessary to adapt to changing environments and thereby confer an evolutionary advantage of sexual over asexual reproduction. Using the green alga, Chlamydomonas reinhardtii, we investigated the effect of a single sexual episode on adaptation of heterotrophic growth on different carbon sources. In an initial mixture of isolates, sex was induced and the resulting offspring constituted the sexual populations, along with any unmated vegetative cells; the unmated mixture of isolates represented the asexual populations. Mean and variance in division rates (i.e., fitness) were measured four times during approximately 50 generations of vegetative growth in the dark on all possible combinations of four carbon sources. Consistent with effects of recombination of epistatic genes in linkage disequilibrium, sexual populations initially had a higher variance in fitness, but their mean fitness was lower than that of asexual populations, possibly due to recombinational load. Subsequently, fitness of sexual populations exceeded that of asexual ones, but finally they regained parity in both mean and variance of fitness. Although recombination was not more effective on more complex substrates, these results generally support the idea that sex can accelerate adaptation to novel environments. Corresponding Editor: T. Kawecki