Collaborative Research: RUI: Molecular Sentinels: Secondary Metabolites as Indicators of Environmental Change in an Antarctic Polar Desert

南极洲的栖息地与地球上发现的任何其他栖息地都不同，它们在寒冷、盐度、水分含量和光照条件方面都存在极大的组合变化。南极麦克默多干谷地区的土壤和沉积物中含有独特的微生物，可以应对极端条件的独特组合，但极端微生物如何发挥作用或对这些极端栖息地的变化做出反应在很大程度上仍不清楚。该团队正在利用之前收集的南极麦克默多干燥山谷(MDV)样本来评估微生物极端细菌功能的差异，以应对气温变暖导致的强烈盐度梯度的变化。在不同盐度的实验室微观世界研究中，正在进行基因表达模式和次生代谢物产生的比较分析。这项工作有助于阐明南极洲生命的遗传基础，并展示南极生物群如何进化和适应不断变化的环境。具体地说，这项工作正在展示与环境相关的盐度变化如何导致次生代谢物的差异表达，这些分离物以前是从干燥山谷地区维多利亚州莱特谷西端的高盐度Don Juan池塘收集的。细胞培养在不同盐度下的转录本正在进行测序和比较，以确定细胞新陈代谢的重大变化，特别是次生代谢途径。从一系列盐碱地收集的其他以前收集的样本类型(土壤、冰川冰、沉积物和卤水)正被用于改进未来实地工作的方法，并为学生提供培训机会。这一计划包括各种其他更广泛的影响。该项目由两名女性PI领导，其中一人是颜色学院，这将扩大黑人妇女和女孩对南极科学的参与。妇女和有色人种在科学、技术、工程和数学(STEM)领域的代表性仍然不足，特别是在地球科学领域。该项目还旨在提供强有力的机会，将STEM研究与本科教育相结合，特别是在史密斯学院，这是一家以本科为主的女子院校。至少有1名研究生和4名本科生将参与该项目，一些人将参与在国际会议上展示成果。该计划还与教育专家合作开发相关课程，供中学生使用。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Antarctica habitats are unlike any others found on the planet with extreme combined variations in cold, salinity, moisture content and light availability. Soils and sediments from the Antarctic McMurdo Dry Valley’s region harbor unique microorganisms that can cope with the unique combination of extreme conditions, but specifically how extremophile microbes function or respond to change in these extreme habitats is still largely unknown. This team is utilizing previously collected Antarctic McMurdo Dry Valleys (MDV) samples to evaluate differences in microbial extremophile function in response to changes in strong salinity gradients caused by warming temperatures. Comparative analyses of gene expression patterns and secondary metabolite production are being undertaken in lab-based microcosm studies with varying salinities. This work is helping to elucidate the genetic underpinnings for life in Antarctica and show how Antarctic biota evolve and adapt to a changing environment. Specifically, the work is showing how environmentally relevant changes in salinity will induce differential expression of secondary metabolites in isolates previously collected from the hypersaline Don Juan Pond in the western end of Wright Valley, Victoria Land in the Dry Valleys region. Transcriptomes of cell cultures under varying salinities are being sequenced and compared to determine significant changes to cellular metabolism, particularly secondary metabolic pathways. Additional previously collected sample types (soils, glacier ice, sediments, and brines) collected from a range of salinities are being used to refine methodologies for future field work and provide training opportunities for students. This program includes a variety of other broader impacts. This project is led by two female PIs, one of whom is a faculty of color, which will broaden the participation of Black women and girls in Antarctic Science. Women and people of color are still underrepresented in science, technology, engineering and math (STEM) fields, especially in the Geosciences. The program is also designed to provide strong opportunities to integrate STEM research with undergraduate education, especially at Smith College, a predominantly undergraduate women’s institution. At least one graduate student and 4 undergraduates will be involved in the project, and some will participate in presenting results at international meetings. The program is also developing related curriculum in partnership with education specialists to be used with middle school students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.