Non-Mendelian transmission has been reported for various genetic elements, ranging from small transposons to entire chromosomes. One prime example of such a transmission pattern are B chromosomes in plants and animals. Accessory chromosomes in fungi are similar to B chromosomes in showing presence/absence polymorphism and being non-essential. How these chromosomes are transmitted during meiosis is however poorly understood—despite their often high impact on the fitness of the host. For several fungal organisms, a non-Mendelian transmission or a mechanistically unique meiotic drive of accessory chromosomes have been reported. In this review, we provide an overview of the possible mechanisms that can cause the non-Mendelian transmission or meiotic drives of fungal accessory chromosomes. We compare processes responsible for the non-Mendelian transmission of accessory chromosomes for different fungal eukaryotes and discuss the structural traits of fungal accessory chromosomes affecting their meiotic transmission. We conclude that research on fungal accessory chromosomes, due to their small size, ease of sequencing, and epigenetic profiling, can complement the study of B chromosomes in deciphering factors that influence and regulate the non-Mendelian transmission of entire chromosomes.

已报道各种遗传元件的非孟德尔传递，范围从小的转座子到整个染色体。这种传播模式的一个主要例子是植物和动物中的 B 染色体。真菌中的辅助染色体与 B 染色体相似，存在/不存在多态性并且是非必需的。然而，人们对这些染色体在减数分裂过程中如何传递知之甚少——尽管它们通常对宿主的适应性有很大影响。对于几种真菌生物体，已报道了辅助染色体的非孟德尔传递或机械上独特的减数分裂驱动。在这篇综述中，我们概述了可能导致真菌辅助染色体的非孟德尔传递或减数分裂驱动的可能机制。我们比较了不同真菌真核生物副染色体非孟德尔传递的过程，并讨论了影响其减数分裂传递的真菌副染色体的结构特征。我们的结论是，由于真菌辅助染色体尺寸小、易于测序和表观遗传分析，对真菌辅助染色体的研究可以补充对 B 染色体的研究，破译影响和调节整个染色体非孟德尔传递的因素。