The Genetics and Ecology of Toxic Yeasts

致命的有毒酵母分泌对其他酵母有毒的蛋白质。P.I.s感兴趣的是评估有毒酵母在酵母物种的自然群落组织中的作用。研究人员过去的工作表明，这些酵母菌在自然界中相对普遍，在所有被研究的群落中至少存在一种酵母菌（即与各种仙人掌的茎坏死、树木的黏液流动和水果的腐烂组织相关的独特酵母菌群落）。侦探他将研究两种不同的酵母，毕赤酵母和耐温酵母，它们分别发生在腐烂的水果和仙人掌的腐烂茎中。有毒P. Kluveri系统特别有趣，因为它有一个非常灵活的遗传系统，显示物种特定的杀伤基因型。为了了解和联系遗传学和生态学的知识，研究人员将进行深入的生态学调查，分析P. Kluyveri的基因型以及相关酵母物种的抗性表型。这项工作，与详细的实验室遗传分析和旨在揭示特定杀手基因型的适应性意义的现场/实验室实验并行，应该允许评估毒素产生对社区组织的重要性。拟对耐温假单胞菌的研究将从一个相对不同的系统中提供比较信息；一个受寄主（仙人掌）和地理（索诺兰沙漠）限制的系统。总体目标是了解社区结构的基本原因。酵母中的致命毒素为研究干扰竞争机制清晰明确的案例提供了机会。

Deadly Toxic yeasts secrete proteins that are toxic to other yeasts. The P.I.s interested in evaluating the role of toxic yeasts in the organization of natural communities of yeasts species. The investigators past work has shown that these yeasts are relatively common in nature with at least one species present in all communities examined (i.e. the distinct yeasts communities associated with stem necroses of various cacti, slime fluxes of trees and decaying tissue of fruits). The P.I.'s will investigate two different yeasts, Pichia Kluyveri and P. thermotolerans, that occur in rotting fruits and decaying stems of cactus respectively. The system of Toxic P. Kluveri is especially interesting since it has a very flexible genetic system that displays species specific killing genotypes. In order to understand and link the knowledge on both the genetics and ecology the investigators will do an in depth ecological survey that assays genotypes of P. Kluyveri in conjunction with he resistance phenotypes of associated yeast species. This work, in parallel with detailed laboratory genetic analysis and field/laboratory experiments designed to reveal the adaptive significance of specific killer genotypes should allow the evaluation of the importance of toxin production to the organization of the community. The proposed work with P. thermotoloerans will provide comparative information from a relative different system; an system that is restricted terms of hosts (saguaro cactus) and geography (Sonoran Desert). The overall goal is to understand the fundamental reasons for community structure. Deadly toxins in yeasts represent an opportunity to study a case where the mechanism of interference competition is clear and unambiguous.