Hartl D L, Dempster E R, Brown S W
Genetics. 1975 Nov;81(3):553-69. doi: 10.1093/genetics/81.3.553.
Certain features reminiscent of sexuality occur in the vegetative life cycle of some filamentous fungi such as Neurospora crassa. Hyphal fusions can occur between genetically different individuals, thereby endowing the new composite mycelium, a heterokaryon, with some of the advantages of heterozygosity usually associated with diploid organisms. In N. crassa, however, there are a number of incompatibility loci which prevent formation of heterokaryons unless the alleles at the incompatibility loci are identical in the two mycelia. The selection pressures that maintain incompatibility polymorphisms are not known. We suggest here that they are maintained because they prevent a kind of exploitation of heterokaryons by nuclei that are nonadaptive in homokaryons but that enjoy a proliferative advantage over other nuclei in heterokaryons. A mathematical model that abstracts the major features of the vegetative life cycle of Neurosopra crassa has been developed, and the action of selection in this model and various extensions of it is such as to maintain polymorphisms of vegetative incompatibility factors.
在一些丝状真菌（如粗糙脉孢菌）的营养生命周期中会出现某些类似有性生殖的特征。遗传上不同的个体之间可能发生菌丝融合，从而使新形成的复合菌丝体（异核体）具备一些通常与二倍体生物相关的杂合优势。然而，在粗糙脉孢菌中，存在许多不相容位点，除非两个菌丝体中不相容位点的等位基因相同，否则会阻止异核体的形成。维持不相容多态性的选择压力尚不清楚。我们在此提出，它们得以维持是因为它们能防止某些细胞核对异核体的一种利用，这些细胞核在同核体中是非适应性的，但在异核体中比其他细胞核具有增殖优势。已经建立了一个抽象出粗糙脉孢菌营养生命周期主要特征的数学模型，该模型及其各种扩展模型中的选择作用能够维持营养不相容因子的多态性。
