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

南极洲的栖息地不同于地球上其他任何地方，在寒冷、盐度、水分含量和光照方面都有极端的综合变化。南极麦克默多干谷地区的土壤和沉积物中蕴藏着独特的微生物，这些微生物可以应对极端条件的独特组合，但具体来说，极端微生物如何在这些极端栖息地发挥作用或对变化做出反应，在很大程度上仍然是未知的。该团队正在利用先前收集的南极麦克默多干谷（MDV）样品来评估微生物极端微生物功能的差异，以响应由变暖引起的强盐度梯度变化。基因表达模式和次生代谢物产生的比较分析正在不同盐度的实验室微观研究中进行。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。具体来说，这项工作显示了环境相关的盐度变化将如何诱导先前从干谷地区维多利亚地赖特谷西端的高盐唐胡安池塘中收集的分离物的次生代谢物的差异表达。正在对不同盐度下细胞培养的转录组进行测序和比较，以确定细胞代谢的重大变化，特别是次级代谢途径。以前从不同盐度收集的其他样品类型（土壤、冰川冰、沉积物和盐水）正在用于改进未来实地工作的方法，并为学生提供培训机会。该计划还包括各种其他更广泛的影响。该项目由两名女性pi领导，其中一名是有色人种教师，这将扩大黑人妇女和女孩对南极科学的参与。女性和有色人种在科学、技术、工程和数学（STEM）领域的代表性仍然不足，尤其是在地球科学领域。该项目还旨在提供强大的机会，将STEM研究与本科教育相结合，特别是在以本科生为主的史密斯学院（Smith College）。至少一名研究生和四名本科生将参与该项目，其中一些将参与在国际会议上展示结果。该项目还与教育专家合作开发相关课程，以供中学生使用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.