Spirito F, Rizzoni M, Rossi C
Department of Genetics and Molecular Biology, Faculty of MFN Sciences, La Sapienza University, Rome, Italy.
Theor Popul Biol. 1993 Aug;44(1):80-94. doi: 10.1006/tpbi.1993.1019.
The fate of an underdominant chromosomal mutant was investigated in multideme models with high rates of local extinction and colonization. Four models with different patterns of colonization (number of colonists and place of origin of colonists) were studied by performing a large number of computer simulations with the Monte Carlo method for several sets of values of the following parameters: coefficient of selection against the heterozygote, extinction rate of each deme, deme size, and number of demes. The probability of the newly arisen rearrangement being established in the multi-deme system depends strongly on the pattern of colonization, other things being equal. In the three models in which there is absent or scarce mixing of gene pools of different demes when a new deme is founded, the fixation probability of the new chromosomal rearrangement is rather close to that calculated by R. Lande (1979, Evolution 33, 234-251; 1985, Heredity 54, 323-332), which is equal to the corresponding probability in a single deme divided by the number of demes. In the model with extensive mixing of gene pools of demes, the corresponding probability is lower (considerably in some cases). Furthermore, in the models where the fixation probability is higher, the analysis of the time of the process leads to the conclusion that in systems consisting of a large number of demes, overlapping of several different processes of fixation of chromosomal rearrangements occurs.
在具有高局部灭绝和定殖率的多群体模型中，研究了一个隐性不足的染色体突变体的命运。通过蒙特卡罗方法对以下几组参数值进行大量计算机模拟，研究了四种具有不同定殖模式（定殖者数量和定殖者来源地）的模型：针对杂合子的选择系数、每个群体的灭绝率、群体大小和群体数量。在其他条件相同的情况下，新出现的重排在多群体系统中得以确立的概率强烈依赖于定殖模式。在三个模型中，当建立一个新群体时，不同群体的基因库缺乏或很少混合，新染色体重排的固定概率相当接近于R.兰德（1979年，《进化》33卷，234 - 251页；1985年，《遗传》54卷，323 - 332页）计算的概率，该概率等于单个群体中的相应概率除以群体数量。在具有群体基因库广泛混合的模型中，相应概率较低（在某些情况下相当低）。此外，在固定概率较高的模型中，对过程时间的分析得出结论，在由大量群体组成的系统中，会发生几种不同染色体重排固定过程的重叠。
