Marinković D, Ayala F J
Genetics. 1975 Jan;79(1):85-95. doi: 10.1093/genetics/79.1.85.
We have studied in Drosophila pseudoobscura the effect of allozyme variation on seven fitness components: female fecundity, egg hatchability, egg-to-adult survival under near-optimal and under competitive conditions, rate of development under near-optimal and under competitive conditions, and mating capacity of males. Three genotypes at each of two loci, Pgm-1 and Me-2, have been studied in various combinations. These two loci are highly polymorphic in natural populations of D. pseudoobscura. Statistically significant differences involving one or more genotypes exist for all components of fitness. No single genotype is best for all fitness components; rather the relative fitnesses of genotypes are reversed when different parameters are considered, or when they are studied in different environmental conditions. Also, the average egg-to-adult survival and rate of development are better when different genotypes are reared together than when they occur in pure culture. Four different modes of selection have been uncovered by our experiments. These forms of selection may account for the persistence of the two allozyme polymorphisms in nature, and for previously observed seasonal fluctuations of the allelic frequencies in natural populations.
雌蝇繁殖力、卵孵化率、在接近最优条件和竞争条件下从卵到成虫的存活率、在接近最优条件和竞争条件下的发育速率以及雄蝇的交配能力。对Pgm - 1和Me - 2这两个位点上的三种基因型进行了各种组合的研究。这两个位点在拟暗果蝇的自然种群中具有高度多态性。在所有适合度组分中，涉及一种或多种基因型的差异具有统计学意义。没有单一基因型对所有适合度组分都是最优的；相反，当考虑不同参数或在不同环境条件下进行研究时，基因型的相对适合度会发生逆转。此外，将不同基因型一起饲养时，从卵到成虫的平均存活率和发育速率比纯培养时更好。我们的实验发现了四种不同的选择模式。这些选择形式可能解释了这两种等位酶多态性在自然界中的持续存在，以及先前观察到的自然种群中等位基因频率的季节性波动。
