Developmental Evolution of Fertilization Biology In Ancient Angiosperm Lineages

经过长期的经验和知识停滞，许多关于被子植物多样化初始阶段的百年范式正在被改写。现在有证据表明，被子植物进化的最早阶段可能具有高度的发育实验和结构不稳定性的特点。相对于花形态学、营养解剖学和生理生态学在古代被子植物谱系中的进化，很少有人注意重建显花植物早期胚胎学特征的多样性。计划研究的明确目标是从进化发育的角度研究一组物种的雌配子体发育、双受精和胚乳形成的基本和高度相关的过程，这些物种是专门选择来代表显花植物基部分支之间多样性的广度的。（1）最早的开花植物是否具有双受精过程，而某些古老的被子植物谱系是否丧失了这一过程？2)被子植物祖先雌配子体的发育模式和成熟结构是什么？3)在被子植物的基部谱系中是否存在额外的和以前没有记载的雌配子体发育模式和成熟结构？4)早期被子植物胚乳的倍性和遗传组成（如母本与父本基因组比例）是如何进化的？除了建立能够解释雌配子体结构和胚乳遗传结构和倍性多样性的一般发育原则外，计划中的研究将对了解开花植物进化多样性早期阶段特征进化的克里思和模式的更一般方面做出重大贡献。拟议的研究将对科学中人力资源的开发做出重大贡献。弗里德曼实验室的成员（本科生，研究生，博士后，技术人员）有机会解决进化生物学中一些最基本和长期存在的问题，并发展独立的智力技能。实验室的所有成员都负有重大的科学责任。一个博士学生，埃里克马德里，是一个代表性不足的群体在科学（西班牙裔）的成员。他将直接得到拟议的研究补助金的支持。埃里克致力于提高少数群体参与科学的水平，并已经在为科学界代表性不足的其他成员树立榜样方面产生了重大影响。目前，弗里德曼实验室的大多数成员都是女性，并渴望成为生命科学领域的教育家和/或实践科学家。一位名叫克尔斯滕·瑞尔森的技术人员将得到拟议中的研究资助，他计划进入公立学校的科学教育事业。明年秋天，她将为科罗拉多州的教学证书而努力。她在弗里德曼实验室的直接参与研究应该直接使她未来的生物学学生受益。另一位将得到计划中的研究资助的技术人员，阿曼达雷德福，热衷于追求研究机会，这将导致研究生学习。最后，通过REU计划，本科生将besupported获得PI，威廉·弗里德曼实验室的第一手研究经验。从本质上讲，虽然与该提案相关的绝大多数资金将用于支持解决基础和长期存在的科学问题，但这些资金将在支持下一代生命科学家和教育家的发展方面发挥关键作用。最后，预计从计划研究中得出的基本发现将像过去一样，被纳入大学教科书。因此，这项研究应该对整个美国的本科生和研究生课程的发展产生影响。

1Award Abstract and Statement of Broader Impacts of Planned ResearchAfter a long period of empirical and intellectual stagnation, many of the century-old paradigms about theinitial phases of the diversification of angiosperms are in the midst of being rewritten. It is now evidentthat the earliest phases of angiosperm evolution may have been characterized by a very high degree ofdevelopmental experimentation and structural lability. In contrast to concerted efforts to study theevolution of floral morphology, vegetative anatomy and ecophysiology among ancient angiospermlineages, little attention has been paid to reconstructing the early diversification of embryological featuresamong flowering plants. It is the explicit goal of the planned research to study the basic and highlyinterrelated processes of female gametophyte development, double fertilization, and endosperm formationfrom an evolutionary developmental perspective in a set of species specifically chosen to represent thebreadth of diversity among basal clades of flowering plants.The following four interrelated questions will be addressed: 1) Did the earliest flowering plants possess aprocess of double fertilization, and have some ancient angiosperm lineages lost this process? 2) What wasthe developmental pattern and mature structure of the ancestral angiosperm female gametophyte? 3) Arethere additional and previously undocumented developmental patterns and mature structures of femalegametophytes among basal angiosperm lineages? 4) How has ploidy and genetic constitution (e.g. thematernal to paternal genomic ratio) of early angiosperm endosperm evolved? Beyond establishinggeneral developmental principles that can explain the diversification of female gametophyte structure andendosperm genetic structure and ploidy, the planned research will make a significant contribution tounderstanding more general aspects of the tempo and mode of character evolution during the earliestphases of the evolutionary diversification of flowering plants.The proposed research will contribute significantly to the development of human resources in thesciences. Members of the Friedman lab (undergraduates, graduate students, postdoctorals, technicians)have the opportunity to grapple with some of the most basic and longstanding questions in evolutionarybiology, and to develop independent intellectual skills. All members of the lab are charged withsignificant scientific responsibility. One Ph.D. student, Eric Madrid, is a member of an underrepresentedgroup in the sciences (Hispanic). He will be directly supported by the proposed research grant. Eric iscommitted to outreach efforts to improve the level of participation of minorities in the sciences andalready has had a major impact in serving as a role model for other members of underrepresented groupsin the sciences.Currently, most of the members of the Friedman lab are women and aspire to careers in the life sciencesas educators and/or practicing scientists. One technician, Kirsten Ryerson, who will be supported by theproposed research grant, plans to enter a career in public school science education. She will beginworking towards a teaching certificate for the state of Colorado next fall. Her direct engagement inresearch in the Friedman lab should directly benefit her future biology students. Another technician whowill be supported by the planned research grant, Amanda Redford, is keen to pursue researchopportunities that will lead to graduate study. Finally, through the REU program, undergraduates will besupported to gain first hand research experience in the laboratory of the PI, William Friedman. Inessence, while the vast majority of funds associated with this proposal will go to support the solution ofbasic and longstanding scientific questions, these funds will play a critical role in supporting thedevelopment of members of the next generation of life scientists and educators.Finally, it is anticipated, that the basic findings derived from the planned research will, as has been thecase in the past, be covered in college level textbooks. Thus, the research should have an impact onundergraduate and graduate curriculum development throughout the U.S.