Analysis of Plant DNA Preservation in Woodrat Middens From the Late Pleistocene to the Present

晚更新世至今林鼠丘陵植物DNA保存分析

• 批准号: 9706183
• 负责人: Edward Golenberg
• 金额: $ 12.01万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706183&HistoricalAwards=false
• 关键词: Analysis; Plant; DNA; Preservation; Woodrat

9706183 Golenberg During the Quaternary, the Earth underwent the last major environmental changes, which were manifested by dramatic swings in atmospheric chemistry and climate. These environmental changes coincide with massive shifts in species and community distributions, which inevitably are associated with population fragmentation, ecotype evolution and formation of sibling species. Yet the morphological evidence of patterns of Quaternary evolution remains sparse. Genetic analyses which could document the patterns of evolution have been negligible despite the wealth of well preserved plant and animal tissue in packrat middens. These dry depositions are ideal for the preservation of DNA, allowing one to estimate species ranges, ecotonal boundaries, hybrid zones; and migrational histories with high spatio-temporal resolution. The delayed progress in DNA analyses of this material is the reluctance to support problem driven research utilizing ancient DNA analysis when the reliability, repeatability, and taxonomic and chronological range of DNA preservation is not well established. To determine the contributions of taxonomic breadth, length of time, and geographical/environmental restrictions to long term DNA preservation, material from five plant taxa (Pinus spp., Juniperus spp., Artemisia spp., Atriplex spp., and Yucca spp.) will be sampled over increasing age increments from fresh and recently preserved to material retrieved from woodrat middens from 90 up to +38,000 years old. To complete this aim, our objectives are: ( To extract DNA from dated vegetative material (leaf, needle, scales, and stems) from a wide geographically and chronological range, ( To amplify, sequence, and analyze gene sequences from the chloroplast regions rbcL, trnL to trnF intergenic region, and the nuclear ITS regions of the ribosomal repeats, ( To assess rates of successful retrieval as functions of taxon, age, age and tissue type. Prior results from independent laboratories have demonstrate d that DNA can be extracted from packrat midden material. Our own preliminary results show that DNA regions that are diagnostic to the subspecies level can be retrieved. The ultimate long range goal of our research is to exploit the large amounts of subfossil material to combine, morphological, physiological, biogeographical studies with the underlying genetic dynamics of the populations as they evolved and migrated during the Quaternary. This goal will be the first merger of population genetic and paleontological studies, and may serve as tests to our understanding of the relevance of microevolution to macroevolution. Additionally, in terms of practical implications of the long term goals, defining the evolutionary processes behind these historical occurrences is manifestly relevant towards understanding and predicting modern biospheric responses to natural and anthropogenic climatological changes.

9706183 Golenberg 在第四纪期间，地球经历了最后一次重大环境变化，表现为大气化学和气候的剧烈波动。 这些环境变化与物种和群落分布的巨大变化同时发生，这不可避免地与种群破碎、生态型进化和兄弟物种的形成有关。 然而，第四纪演化模式的形态学证据仍然很少。 尽管狼群中保存完好的丰富动植物组织，但记录进化模式的遗传分析却可以忽略不计。 这些干燥沉积物非常适合保存 DNA，使人们能够估计物种范围、生态带边界、混合区；以及具有高时空分辨率的迁徙历史。 这种材料的 DNA 分析进展缓慢，是因为当 DNA 保存的可靠性、可重复性以及分类学和年代范围尚未确定时，不愿支持利用古代 DNA 分析进行问题驱动的研究。 为了确定分类广度、时间长度和地理/环境限制对长期 DNA 保存的贡献，将对来自 5 个植物类群（松属、杜松属、蒿属、滨藜属和丝兰属）的材料进行采样，随着年龄的增加，从新鲜和最近保存的材料到从 90 至 38,000 年的木鼠巢中回收的材料 老的。 为了完成这一目标，我们的目标是：（从广泛的地理和年代顺序范围内的过时植物材料（叶、针、鳞片和茎）中提取 DNA，（对叶绿体区域 rbcL、trnL 至 trnF 基因间区域以及核糖体重复序列的核 ITS 区域的基因序列进行扩增、测序和分析，（评估作为分类群功能的成功检索率， 年龄、年龄和组织类型。 独立实验室先前的结果表明，可以从狼群的粪便材料中提取 DNA。 我们自己的初步结果表明，可以检索对亚种水平具有诊断意义的 DNA 区域。 我们研究的最终长期目标是利用大量的亚化石材料，将形态学、生理学、生物地理学研究与潜在的遗传动力学相结合。 第四纪期间人口的进化和迁移。 这一目标将是群体遗传学和古生物学研究的首次合并，并可能作为我们对微观进化与宏观进化相关性理解的检验。 此外，就长期目标的实际意义而言，定义这些历史事件背后的进化过程显然与理解和预测现代生物圈对自然和人为气候的反应相关。 变化。