Department of Biology, University of Houston, Houston, Texas 77004.
Genetics. 1986 Dec;114(4):1191-211. doi: 10.1093/genetics/114.4.1191.
Effects of a population bottleneck (founder-flush cycle) upon quantitative genetic variation of morphometric traits were examined in replicated experimental lines of the housefly founded with one, four or 16 pairs of flies. Heritability and additive genetic variances for eight morphometric traits generally increased as a result of the bottleneck, but the pattern of increase among bottleneck sizes differed among traits. Principal axes of the additive genetic correlation matrix for the control line yielded two suites of traits, one associated with general body size and another set largely independent of body size. In the former set containing five of the traits, additive genetic variance was greatest in the bottleneck size of four pairs, whereas in the latter set of two traits the largest additive genetic variance occurred in the smallest bottleneck size of one pair. One trait exhibited changes in additive genetic variance intermediate between these two major responses. These results were inconsistent with models of additive effects of alleles within loci or of additive effects among loci. An observed decline in viability measures and body size in the bottleneck lines also indicated that there was nonadditivity of allelic effects for these traits. Several possible nonadditive models were explored that increased additive genetic variance as a result of a bottleneck. These included a model with complete dominance, a model with overdominance and a model incorporating multiplicative epistasis.
研究了在由 1、4 或 16 对果蝇建立的重复实验品系中，种群瓶颈（奠基者flush 循环）对形态计量性状的数量遗传变异的影响。八个形态计量性状的遗传力和加性遗传方差通常由于瓶颈而增加，但瓶颈大小之间的增加模式在不同性状之间存在差异。对照系的加性遗传相关矩阵的主轴产生了两套性状，一套与总体体型有关，另一套与体型基本无关。在前一组包含五个性状中，在四对的瓶颈大小中加性遗传方差最大，而在后一组的两个性状中，在最小的一对的瓶颈大小中发生了最大的加性遗传方差。一个性状表现出介于这两种主要反应之间的加性遗传方差变化。这些结果与等位基因在基因座内的加性效应或基因座间的加性效应模型不一致。在瓶颈线中观察到的生存力和体型的下降也表明这些性状的等位基因效应是非加性的。探讨了几种可能的非加性模型，这些模型由于瓶颈而增加了加性遗传方差。这些模型包括完全显性模型、超显性模型和包含乘法上位性的模型。
