James Timothy Y, Porter David, Hamrick James L, Vilgalys Rytas
Department of Botany, University of Georgia, Athens, Georgia, 30602.
Departments of Botany and Genetics, University of Georgia, Athens, Georgia, 30602.
Evolution. 1999 Dec;53(6):1665-1677. doi: 10.1111/j.1558-5646.1999.tb04552.x.
The genetic structure of populations of Schizophyllum commune was inferred from electrophoretic variation among 136 individuals at 11 polymorphic allozyme loci to determine the extent of geographic differentiation in this widespread mushroom species. The majority of the genetic variation was contained within populations; however, considerable genetic differentiation was observed among populations (global G = 0.214). Clustering analysis demonstrated that genetic distance was correlated with geographic distance and that a large component of the genetic variation was due to allele frequency differences among populations from the eastern and western hemispheres. Our results also suggest that populations are large and geographically widespread. The lack of fixed genetic differences among intercontinental populations at any of the allozyme loci suggests that long-distance spore dispersal may counter the effects of genetic drift in this cosmopolitan species. These results are contrasted with a previous description of the same collection, in which the mating allele distribution of the species displayed no population substructure at any geographic scale (Raper et al. 1958). Broader implications of this study are that both species and mating allele distributions may not be correlated with long-distance gene flow in basidiomycete fungi.
通过对裂褶菌11个多态性等位酶位点上136个个体的电泳变异进行分析，推断出裂褶菌群体的遗传结构，以确定这种广泛分布的蘑菇物种的地理分化程度。大部分遗传变异存在于群体内部；然而，群体间也观察到了相当程度的遗传分化（全局G = 0.214）。聚类分析表明，遗传距离与地理距离相关，并且遗传变异的很大一部分是由于东半球和西半球群体之间的等位基因频率差异所致。我们的结果还表明，群体规模较大且分布广泛。在任何等位酶位点上，洲际群体之间缺乏固定的遗传差异，这表明长距离孢子传播可能抵消了这种世界性物种中遗传漂变的影响。这些结果与之前对同一样本的描述形成对比，在之前的描述中，该物种的交配等位基因分布在任何地理尺度上都没有显示出群体亚结构（Raper等人，1958年）。这项研究更广泛的意义在于，物种和交配等位基因分布可能都与担子菌中的长距离基因流动无关。
