Soft Tissues and Cellular Features in Fossil Vertebrates

EAR-0541744SCHWEITZER拟议研究的主要目标是：1)识别和表征保存在不同时间的多个化石样本中的软组织和细胞特征，以及2)测试关于细胞和亚细胞结构和分子信息在各种特殊保存的化石样本中的持久性的假设。这项研究涉及以下内容：假设1：形态软组织和细胞保存可能意味着信息丰富的生物分子片段的保存，如蛋白质或DNA。假设2：脊椎动物组织骨基质中的有机、细胞和分子成分以不同的速度降解，这些差异可以通过对不同时代的化石应用相同的方法来记录。智力优势：对化石标本中分子信息降解的地球化学和生化研究表明，化石的寿命有限，仅限于100万年以下。软组织和细胞结构以原来的透明度、灵活性和弹性保存下来，即作为静止的软组织保存，其寿命和保存潜力预计将大大减少。然而，最近的研究表明，它们确实持续存在。为了了解软组织和细胞是如何被保存的，有必要对它们目前的组成进行表征。拟议的对从化石样本中回收的成分进行免疫化学、光谱和酶分析将识别组成组织和细胞的分子。如果它们是原始的(原始于来源生物体)，它们的识别将在分子和细胞水平上阐明涉及退化、保存和石化的过程，并揭示进化和系统发育模式。通过分析和表征化石标本中的这些残留物，并与现存的脊椎动物血管、细胞和骨基质的成分进行比较，有可能从遗留下来的成分中识别出分子来源的物质，并建立更准确的自然条件下降解路径的模型。然后，所得到的模型可以用于识别其他具有恢复信息分子残留物潜力的化石材料。广泛的影响：研究和教育的整合：PI目前指导2名博士生、1名硕士学生和2名本科生。从2005年秋季开始，另外四名研究生将在她的指导下开始研究项目，所有这些项目都将包含分析部分。这项提案如果获奖，将为他们的研究提供资金，并有助于他们学习和应用新技术方法来研究灭绝生命。此外，PI教授恐龙科学入门和高级课程，并将正在进行的研究结果直接纳入授课材料。扩大未被充分代表的群体的参与：秋季在实验室工作的四名学生(截至2005年秋季)将是女性，其中两名代表少数民族。研究结果的授课：形成这一提议基础的实验的初步结果已经发表在广泛跨学科的期刊上，并且过去和将来都将在几个专业会议上展示。此外，总体成果已通过大众媒体向公众公布。在赠款期间获得的数据将首先通过同行审查程序传播，然后通过媒体和较长但技术性较少的出版物向普通民众提供。最后，这项研究将成为北卡罗来纳州自然科学博物馆和落基山脉博物馆永久展品的一部分，并讨论了通过流行媒体形式向公众传播的其他几个方案。

EAR-0541744SCHWEITZERThe primary objectives of the proposed research are to: 1) identify and characterize soft tissues and cellular features preserved in multiple fossil specimens across time, and 2) test hypotheses concerning persistence of cellular and subcellular structure and molecular information in a variety of exceptionally preserved fossil specimens. This research addresses the following:Hypothesis 1: Morphological soft tissue and cellular preservation may indicate preservation of informative biomolecular fragments, such as proteins or DNA.Hypothesis 2: Organic, cellular, and molecular components within bone matrices of vertebrate tissues each degrade at different rates, and these differences can be documented by applying identical methods to fossils of varying ages.Intellectual Merit:Geochemical and biochemical investigations into degradation of molecular information in fossil specimens suggest a finite lifespan in fossils, limited to well under a million years. The lifespan and preservation potential of soft tissues and cellular structures, preserved with original transparency, flexibility and resilience"i.e., preserved as still soft tissues"have been predicted to be significantly less. And yet, recent research shows that they do persist. To understand how soft tissues and cells are preserved, it is necessary to characterize their present composition. Proposed immunochemical, spectroscopic and enzymatic analyses of components recovered from fossil specimens will identify molecules, which comprise tissues and cells. If primary (original to the source organism), their identification will clarify processes involved in degradation, preservation, and fossilization at the molecular and cellular levels, and reveal evolutionary and phylogenetic patterns. If no original material can be identified, the soft tissues indicate previously unknown geochemical processes resulting in resilient polymeric material retaining morphological and functional identity with original structures.By analyzing and characterizing these remnants in fossil specimens and comparing their compositions to that of extant vertebrate vessels, cells and bone matrix, it may be possible to identify molecular source materials from the components that remain behind, and create more accurate models of degradation pathways under naturally occurring conditions. Resulting models may then be applied to identify other fossil material with potential for recovery of informative molecular remains.Broader Impacts:Integration of research and education: The PI currently supervises 2 PhD students, one Master's student, and two undergraduates. Beginning in fall 2005, four additional graduate students will begin research projects under her direction, all of which will have an analytical component. This proposal, if awarded, will fund their research and contribute to their learning and applying new technological approaches to the study of extinct life. In addition, the PI teaches both introductory and advanced classes in dinosaur science, and includes results from ongoing research directly into lecture material.Broadening the participation of underrepresented groups: Four students (as of fall '05) working in the labs in the fall will be female, and two of these represent minority ethnic groups.Dissemination of research results: Preliminary results of experiments forming the foundation of this proposal have been published in journals that are broadly interdisciplinary, and were and will be presented at several professional meetings. In addition, the overall results have reached the public via the popular media. Data acquired during the tenure of the grant will be disseminated first via peer review processes, then made available to the general population through media outlets and longer, but less technical publications. Finally, this research will be part of permanent exhibits in both the North Carolina Museum of Natural Sciences and the Museum of the Rockies, in a format appropriate for the general public, and several other programs for public dissemination through popular media formats have been discussed.