Fungal mating circuity

通过交配交换遗传信息是一个重要的生物学过程。 在子囊菌中，交配在S.在一些实施方案中，所述方法包括在酿酒酵母中激活MAP激酶模块，其中受体/G蛋白复合物激活控制细胞周期停滞、基因表达和形态的MAP激酶模块。在相关的子囊菌白色念珠菌中，电路的关键元件不同于S。酿酒酵母模型理解这些差异的逻辑对于充分理解真菌交配过程至关重要。 我们将研究电路不同的两个方面-C的不透明状态的要求。白色念珠菌交配，和G α亚基的作用。 单倍体S.酿酒酵母细胞具有固有的交配能力，而C.白色念珠菌细胞需要依赖于细胞类型的表观遗传转换来获得交配能力。在实验室中，这种转换是罕见的，交配能力也不常见。我们已经确定了ofr 1突变，它允许细胞绕过正常的交配要求，并切换到不透明状态，甚至作为a/杂合子交配。我们将以两种方式跟进，建立ofr 1突变允许交配的分子基础，并确定和表征允许a/杂合子交配的其他突变。我们将首先使用双突变体分析来确定ofr 1触发的交配-突变交配信号通路（STE 4）、经典的白色不透明转换机制（WOR 1）和葡萄糖胺摄取（NGT 1）所需的回路。为了找到调节交配的新元素，我们将鉴定GRACE集合中的其他突变，这些突变允许在MTL杂合时切换到不透明形式。基因失活刺激不透明细胞形成的菌株将被鉴定为显示不透明细胞的增强的荧光桃红染色特征。我们还将研究C.白色念珠菌 通常情况下，和亚基在交配过程中扮演相反的角色。In C.我们已经证明，这两个都是交配所必需的。 我们将确定和元件是否执行配对所需的独立功能，或协调单一功能。 为了区分这些可能性，我们将激活通路中的各种下游元件，并确定激活的元件是否抑制和突变体中的一个或两个。我们还将评估受信息素途径影响的其他细胞过程，如白色不透明开关，以评估和的作用是否不同。

The exchange of genetic information through mating is a central biological process. In the ascomycete fungi, mating has been well studied in S. cerevisiae where a receptor/G protein complex activates a MAP kinase module controlling cell cycle arrest, gene expression, and morphology. In the related ascomycete Candida albicans, key elements of the circuitry differ from the S. cerevisiae model. Comprehending the logic of these differences is critical to a full understanding of the fungal mating process. We will investigate two areas where the circuits are different - the requirement for the opaque state for C. albicans mating, and the role of the G alpha subunit. Haploid S. cerevisiae cells are inherently mating competent, while C. albicans cells require a cell-type-dependent epigenetic switch to mating-competence. In the laboratory this switch is rare, and mating competence infrequent. We have identified the ofr1 mutation that allows the cells to bypass normal requirements for mating, and switch to the opaque state and mate even as a/ heterozygotes. We will follow up in two ways establish the molecular basis for the ofr1 mutation allowing mating, and identify and characterize other mutations that permit a/ heterozygotes to mate. We will first use double mutant analysis to establish which circuits are required for ofr1-triggered mating - mutating the mating signalling pathway (STE4), the classic white-opaque switching machinery (WOR1) and glucosamine uptake (NGT1). To find new elements regulating mating we will identify other mutations in the GRACE collection allowing switching to the opaque form while MTL heterozygous. Strains where gene inactivation stimulates opaque cell formation will be identified as showing the enhanced phloxine staining characteristic of opaque cells. We will also investigate G protein circuitry of C. albicans. Normally the and subunits play opposing roles in the mating process. In C. albicans we have shown that both and are required for mating. We will determine if the and elements perform independent functions required for mating, or coordinate a single function. To distinguish these possibilities we will activate a variety of downstream elements in the pathway, and establish if the activated element suppresses either or both of the and mutants. We will also assess other cellular process influenced by the pheromone pathway such as the white-opaque switch to assess whether the roles of and are different.