Gene flow within populations can occur by sexual and/or parasexual means. Analyses of experimental and in silico work are presented relevant to possible gene flow within the aspergilli. First, the discovery of mating-type (MAT) genes within certain species of Aspergillus is described. The implications for self-fertility, sexuality in supposedly asexual species and possible uses as phylogenetic markers are discussed. Second, the results of data mining for heterokaryon incompatibility (het) and programmed cell death (PCD) related genes in the genomes of two heterokaryon incompatible isolates of the asexual species Aspergillus niger are reported. Het-genes regulate the formation of anastomoses and heterokaryons, may protect resources and prevent the spread of infectious genetic elements. Depending on the het locus involved, hetero-allelism is not tolerated and fusion of genetically different individuals leads to growth inhibition or cell death. The high natural level of heterokaryon incompatibility in A. niger blocks parasexual analysis of the het-genes involved, but in silico experiments in the sequenced genomes allow us to identify putative het-genes. Homologous sequences to known het- and PCD-genes were compared between different sexual and asexual species including different Aspergillus species, Sordariales and the yeast Saccharomyces cerevisiae. Both het- and PCD-genes were well conserved in A. niger. However some point mutations and other small differences between the het-genes in the two A. niger isolates examined may hint to functions in heterokaryon incompatibility reactions.

中文翻译：

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曲霉中的性和营养相容性基因。

群体内的基因流动可以通过性和/或性欲的方式发生。提出了与曲霉内可能的基因流动相关的实验和计算机工作分析。首先，描述了某些曲霉属物种中交配型 (MAT) 基因的发现。讨论了对自我生育能力的影响，所谓无性物种的性行为以及作为系统发育标记的可能用途。其次，报告了对无性种黑曲霉的两个异核不相容分离株的基因组中的异核不相容性（het）和程序性细胞死亡（PCD）相关基因的数据挖掘结果。Het基因调节吻合和异核的形成，可以保护资源并防止传染性遗传元件的传播。根据所涉及的 het 轨迹，不能容忍异种等位现象，遗传不同个体的融合会导致生长抑制或细胞死亡。A. niger 中异核不相容性的高自然水平阻止了对所涉及的 het 基因的准性分析，但在测序的基因组中的计算机实验使我们能够识别推定的 het 基因。在不同的有性和无性物种之间比较了已知 het 和 PCD 基因的同源序列，包括不同的曲霉属、Sordariales 和酵母酿酒酵母。het 和 PCD 基因在黑曲霉中都非常保守。然而，所检查的两个黑曲霉分离株中 het 基因之间的一些点突变和其他小的差异可能暗示在异核不相容性反应中的功能。