Molecular Analysis of Fungal Sporulation

丝状菌中分生孢子（无性孢子）的形成 子囊菌，构巢曲霉，涉及生产 由几种不同组织组成的分化结构 类型和结果在合成大量的新聚 (A)+ RNA在未分化的菌丝体中未观察到。 一个重要 这种生物的特征是分生孢子通常是 在深层培养中被抑制，但可以通过改变 生长环境与空气的界面。 转移（transfer） 从液体到固体培养基的菌落），然而，将允许 只有在生物体达到一定的 状态的变化称为发展能力。 拟议 研究的方向是确定 发展能力和理解机制 参与调节途径的启动。 预诱导 突变体的基因特征，但分子 需要一种方法来确定不同的预诱导 函数相互作用，并推导出如何表达 预诱导基因启动了大量 这些基因被转录激活， 在诱导状态下生长。 本提案的具体目标 是（l）克隆由以下代表的野生型基因： 诱导前和诱导后早期突变体，（2）比较 这些基因的转录活性与它们的时间 通过温度变化分析确定的表达式，以及（3） 通过确定转录是否 一个基因的突变会受到另一个基因突变的影响。 发展，一个全能的未分化的过渡 细胞到分化细胞的调节集合，是一种 复杂的过程 使用“简单的”真核生物， 作为曲霉菌作为模型系统的机制中使用的 分化过程可以提示 了解更复杂的生物体的过程。 结果 从这项工作中获得的信息应该能更深入地了解 神秘的分化过程。

The formation of conidia (asexual spores) in the filamentous ascomycete, Aspergillus nidulans, involves the production of differentiated structures composed of several different tissue types and results in the synthesis of a large number of new poly (A)+ RNAs not observed in undifferentiated mycelia. An important feature of this organism is that conidiation is normally suppressed in submerged culture, but can be initiated by changing the growth habitat to an air interface. Induction (the transfer of colonies from liquid to solid media), however, will permit the initiation of conidiation only after the organism has attained a change of state termed developmental competence. The proposed research is directed toward determining the molecular basis of developmental competence and toward understanding the mechanisms involved in the initiation of a regulatory pathway. Preinduction mutants have been genetically characterized, but a molecular approach is required to determine how different preinduction functions interact, and to deduce how the expression of preinduction genes initiates the expression of the large number of post induction genes which are transcriptionally activated by growth in the induced state. The specific aims of this proposal are (l) to clone the wild-type genes represented by the preinduction and early postinduction mutants, (2) to compare the transcriptional activity of these genes with their time of expression as ascertained by temperature-shift analysis, and (3) to identify gene interactions by determining if the transcription of one gene is affected by the mutation of another gene. Development, the transition of a totipotent undifferentiated cell to a regulated collection of differentiated cells, is a complex process. The use of a "simple" eukaryotic organism such as Aspergillus as a model system for mechanisms utilized in the differentiation process can suggest approaches and mechanisms for understanding the process in more complex organisms. The results to be obtained from this work should give greater insight into the as yet mysterious process of differentiation.