Evolutionary dynamics of lichen-forming algae fungi and natural products

藻类和真菌的成分相互作用产生地衣协会，形成一个复杂的叶状体，不同于单独的两个共生伙伴。叶状体的形态变化在自然界中已有报道，并与环境条件的变化相关。地衣适应不断变化的条件的能力有助于它们的生存能力，特别是在目前北方气候变化的情况下，在那里驯鹿地衣占主导地位，是大型哺乳动物冬季饮食的重要组成部分。由于地衣很难在培养物中生长，因此很难在控制的培养条件下研究地衣的形态变化。但在培养中容易测量的一个表型特征是天然产物（次级代谢产物）的产生。已经描述了这些代谢物的基因，使基因表达成为可测量的表型，培养条件的变化反映了环境条件的变化。该研究计划的总体目标是了解地衣形成真菌物种之间的进化关系，以及共生体如何受到环境条件变化的影响。这将揭示驱动地衣生物多样性的机制。 一名博士生正在研究Ramalina属成员之间的进化关系，以及该属成员产生的次级代谢产物的进化。另一名博士生正在研究驯鹿地衣（Cladonia sect.Cladina）的进化，以更好地了解有性繁殖和这组地衣适应不断变化的环境条件的能力。地衣真菌选择适应生境的藻类被认为是一种生存策略，因为真菌孢子分散到不同的生境。两名硕士学生将研究水生地衣和陆生地衣中的藻类选择，以了解这些物种如何适应水位或污染水平的变化或环境光线和温度的变化。更好地了解次级代谢产物的适应性和环境调节，可以提供更好的药物化合物，而不会耗尽我们的自然资源。

The algal and fungal components that interact to produce a lichen association, form a complex thallus unlike either of the two symbiotic partners alone. Morphological changes in the thallus have been reported in nature and correlated with changes in environmental conditions. The ability of lichens to adapt to changing conditions is instrumental to their ability to survive especially under the current climate change in the north where members of the Reindeer lichens dominate and form an important component of the winter diet for large mammals. It is difficult to study morphological changes in lichens under controlled culture conditions because lichens are so difficult to grow in culture. But one phenotypic feature that is readily measured in culture is the production of natural products (secondary metabolites). The genes for these metabolites have been described making gene expression a measurable phenotype with changes in culture conditions that reflect changes in environmental conditions. The general goal of this research program is to understand the evolutionary relationships among species of lichen-forming fungi, and how the symbionts are affected by changes in environmental conditions. This will shed light on the mechanisms that drive biodiversity in lichens. One PhD student is studying the evolutionary relationships among members of the genus Ramalina with respect to evolution of the secondary metabolites produced by members of the genus. Another PhD student is examining evolution of the Reindeer lichens (Cladonia sect. Cladina) to better understand sexual reproduction and the ability of this group of lichens to adapt to changing environmental conditions. The selection of algae adapted to the habitat by lichen fungi is thought to be a strategy for survival as the fungal spores are dispersed to different habitats. Two MSc students will examine algal selection in an aquatic lichen and a terrestrial lichen to understand how these species might adapt to changes in water levels or pollution levels or to changes in ambient light and temperature. A better understanding of adaptation and environmental regulation of secondary metabolites may provide better pharmaceutical compounds without depleting our natural resources.