MOLECULAR GENETICS OF HETEROKARYON INCOMPATIBILITY

该提案的广泛的长期目标是分子 粗糙脉孢菌异核体不相容性的描述。 异核体不亲和性是一种遗传系统，其作为一种屏障， 不同基因型菌株的无性融合。 以兼容 当两个菌丝相遇时，两个菌丝融合并交换细胞质和细胞核， 保持其单倍体状态。 在不相容的相遇中，菌丝 融合，但迅速密封从其余的菌丝，并经历一个 快速退化 不相容性由至少10个未链接的 基因座（het基因）。 这些基因中的任何一个的等位基因差异都是足够的 引起不相容反应。 不兼容系统是 感兴趣的原因有两个：它们在真菌中广泛存在，包括 它们代表了一个基本的分子过程， 与细胞色素不同的是， 杀伤性 不相容反应的机制，以及 目前正在通过以下方式寻求对其进行调控：1）克隆、定义， 对一些或所有het基因及其异源等位基因进行测序; 2） 分离和表征干扰 不相容性反应，以确定系统的遗传成分， 从天然变体（het）等位基因显现; 3）克隆和 表征由所述突变体鉴定的基因;和4）表征 het和突变基因的转录和可能的调节 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.