EAGER: Genetic Mechanisms of Meiosis Suppression

智力上的功绩。有性生殖和无性繁殖的进化原因和结果仍然是进化遗传学中最深层次的谜团之一。虽然抑制减数分裂的机制，包括同源重组和分离的丢失，似乎在系统发生学上是广泛可用的，但减数分裂单倍体配子生产转化为有丝分裂二倍体卵子生产的分子基础仍然未知。该项目将使用微型甲壳类动物Paphnia Pulex来解决这个问题，以阐明向孤雌生殖卵子生产过渡的分子和细胞生物学机制。这位首席研究员之前的研究已经确定了一个关键基因，其修改似乎对于将减数分裂转换为有丝分裂是必要的，并确定了包含另外两到三个染色体区域。为了进行这些基因的功能研究，有必要建立含有可能的减数分裂抑制因子的报告基因结构的稳定的杜鹃转基因株系。如果成功，该项目将导致对减数分裂和抑制减数分裂的分子基础的机制的更好理解，这反过来将对应用育种计划产生相当大的影响。可靠的转基因方法的建立将使水蚤系统在分子、细胞和发育生物学中探索一系列额外的问题，从而极大地扩大这一模型系统的研究能力，使其超越水蚤基因组学联合会所体现的已经很大的研究社区。教育和培训工作的重点将是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从开发和实施新技术到研究设计、假设检验和发表的关键方面的全方位科学研究。印第安纳大学支持一些针对高中和本科少数民族学生的暑期项目，首席调查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.