EAGER: Genetic Mechanisms of Meiosis Suppression

知识价值。有性生殖和无性生殖的进化原因和结果仍然是进化遗传学中最深的谜团之一。虽然减数分裂的抑制机制（涉及同源重组和分离的丧失）似乎在系统发育上广泛存在，但减数分裂单倍体配子生产向有丝分裂二倍体卵子生产转化的分子基础仍不清楚。该项目将利用微甲壳类动物水蚤（Daphnia pulex）来解决这一问题，以阐明向单性生殖产卵过渡的分子和细胞生物学机制。首席研究员之前的研究已经确定了一个关键基因，其修饰似乎是将减数分裂转化为有丝分裂所必需的，并确定了包含两到三个其他基因的染色体区域。为了对这些基因进行功能研究，有必要开发出含有减数分裂抑制因子报告基因构建的稳定的毛缕草转基因品系。如果成功，该项目将导致对减数分裂和减数分裂抑制的分子基础机制的进一步了解，这将反过来对应用育种计划有相当大的影响。更广泛的影响。建立可靠的转基因方法将使水蚤系统在分子、细胞和发育生物学中探索更多的问题，从而大大扩展了该模型系统的研究能力，超出了水蚤基因组学联盟中已经存在的大量研究社区。教育和培训工作将侧重于博士后研究人员的职业发展，以及让本科生研究人员接触到全方位的科学探究，从新技术的开发和实施到研究设计、假设检验和发表的关键方面。印第安纳大学为高中和本科少数民族学生提供了一些暑期项目，首席研究员将继续资助这些学生。

Intellectual Merit. The evolutionary causes and consequences of sexual vs. asexual reproduction remain among the deepest mysteries in evolutionary genetics. Although the mechanisms responsible for the suppression of meiosis, which involve a loss of homologous recombination and segregation, appear to be widely available phylogenetically, the molecular basis for the conversion of meiotic haploid gamete production to mitotic diploid egg production remains unknown. The project will address this issue using the microcrustacean Daphnia pulex to elucidate the molecular and cell biological mechanisms underlying the transition to parthenogenetic egg production. The principal investigator's previous research has identified a key gene whose modification appears to be necessary to convert meiosis to mitosis, and as well as identifying chromosomal regions containing two to three others. To perform functional studies of these genes, it will be necessary to develop stable transgenic lines of D. pulex containing reporter gene constructs of the putative meiosis suppressor. If successful, the project will lead to an enhanced understanding of the mechanisms underlying the molecular basis of meiosis and meiosis suppression, which would in turn have considerable implications for applied breeding programs.Broader Impact. The establishment of reliable transgenic methods will open up the Daphnia system to inquiry of a wide array of additional questions in molecular, cellular, and developmental biology, thereby greatly broadening the investigative capacity of this model system beyond the already substantial research community embodied in the Daphnia Genomics Consortium. Educational and training efforts will be focused on the career development of a postdoctoral researcher as well as on exposing undergraduate researchers to the full spectrum of scientific inquiry, from the development and implementation of new techniques to critical aspects of research design, hypothesis testing, and publication. Indiana University supports a number of summer programs for high-school and undergraduate minority students, and the principal investigator will continue to sponsor such students.