MOLECULAR GENETICS OF HETEROKARYON INCOMPATIBILITY

这个提议的广泛的、长期的目标是分子 粗糙脉孢菌异核体不亲和性的描述。 异核体不亲和性是一种遗传系统，它对 不同基因的菌株的无性融合。在兼容的 相遇时，两个菌丝融合并交换细胞质和细胞核，这 维持它们的单倍体状态。在一次不相容的相遇中，菌丝 融合，但迅速与其余菌丝隔离，并经历 迅速退化。不兼容性由至少10个未链接的人确定 基因座(het基因)。其中任何一个的等位基因差异就足够了。 以引起不相容反应。不相容系统是 引起人们兴趣的原因有两个：它们在真菌中广泛存在，包括 致病形式，它们代表了一个基本的分子过程 与细胞质不同的是，它们彼此识别并为自己编程 毁灭。参与不相容反应的机理，以及 正在通过以下具体方式寻求对其进行监管：1)克隆、定义和 部分或全部het基因及其异源等位基因的测序；2) 分离和鉴定干扰基因的突变体 不亲和反应，鉴定系统的遗传成分不是 明显来自自然变异(Het)等位基因；3)克隆和 表征由这种突变体识别的基因；以及4)表征 Het和突变基因的转录和可能的调控 因为它们是克隆的。

The broad, long-term objective of this proposal is the molecular description of heterokaryon incompatibility in Neurospora crassa. Heterokaryon incompatibility is a genetic system that acts as a barrier to the asexual fusion of strains of unlike genotype. In a compatible encounter, two hyphae fuse and exchange cytoplasms and nuclei, which maintain their haploid state. In an incompatible encounter, the hyphae fuse but are rapidly sealed off from the rest of the hyphae and undergo a rapid degeneration. Incompatibility is determined by at least 10 unlinked loci (het genes). An allelic difference at any one of these is sufficient to evoke the incompatibility reaction. Incompatibility systems are of interest for two reasons: they are widespread among the fungi, including pathogenic forms, and they represent a fundamental molecular process by which unlike cytoplasms recognize each other and program their own destruction. The mechanism involved in the incompatibility reaction, and its regulation are being sought specifically by: 1) cloning, defining, and sequencing some or all the het genes and their heterologous alleles; 2) isolating and characterizing mutants that interfere with the incompatibility reaction, to identify genetic components of the system not apparant from the natural variant (het) alleles; 3) cloning and characterizing the genes identified by such mutants; and 4) characterizing the transcription and possibly the regulation of the het and mutant genes as they are cloned.