Dissertation Research: Mendel's First Law of Segregation Revisited: Variation in Chromosome Transmission Through Female Meiosis in Drosophila Melanogaster

9623970兰利减数分裂是二倍体生物产生单倍体配子(即卵子或精子)的生物学过程。传统上认为，给定同源对的每条染色体都有相等的几率传递到配子中。违反这一假设，即某些染色体或多或少地被传递，被称为分离扭曲。分离扭曲的例子在各种各样的生物体中都可以找到，并可以深刻地影响自然种群中遗传变异的动态、水平和模式。通过减数分裂确保染色体传递的基因似乎是表现分离扭曲的理想候选基因。然而，由于种种原因，对这类基因座的研究一直被种群遗传学家所忽视。这项由该奖项资助的研究利用了模式生物--黑腹果蝇的减数分裂基因和减数分裂机制的最新进展，以解决我们对分离扭曲的基本理解的差距。在这个项目中，将评估50条非洲X染色体通过雌性减数分裂传递的染色体保真度的差异。这个实验被设计用来检测与传播到配子的概率相等的假设的偏差。然后将对减数分裂过程中起作用的一系列X连锁基因进行调查。在这项调查中检测到的特定多态将与观察到的染色体传递变异相关。最后，端粒、着丝粒和多态候选基因座对染色体“传递表型”的影响将通过一系列遗传分析直接测量。这项工作揭示的分离扭曲机制对应用遗传学和理论遗传学、影响基因工程、基因治疗和育种计划以改良动植物资源具有重要意义。

9623970 Langley Meiosis is the biological process in which a diploid organism produces haploid gametes (i.e. eggs or sperm). It is traditionally assumed that each chromosome of a given homologous pair has an equal probability of being transmitted into a gamete. Violations of this assumption in which certain chromosomes are transmitted more or less frequently are referred to as segregation distortion. Examples of segregation distortion are found in a wide variety of organisms and can profoundly influence the dynamics, levels and patterns of genetic variation in natural populations. Genes whose function is to ensure chromosome transmission through meiosis would seem to be ideal candidates to exhibit segregation distortion. Yet, for a variety of reasons, the study of this class of genetic loci has been neglected by population geneticists. The research funded by this award takes advantage of recent advances in the understanding of the genes and the mechanisms of meiosis in the model organism, Drosophila melanogaster, to address this the gap in our fundamental understanding of segregation distortion. In this project, variation in the fidelity of chromosome transmission through female meiosis for will be assessed for fifty African X chromosomes. This experiment is designed to detect deviations from the assumption of equal probability of transmission into gametes. A series of X-linked genes which act during meiosis will then be surveyed. Specific polymorphisms detected during this survey will be correlated with the observed variation in chromosome transmission. Finally, the effects of telomeres, centromeres and polymorphic candidate loci on a chromosome's "transmission phenotype" will be directly measured through a series of genetic assays. The mechanisms of segregation distortion revealed in this work are important to applied as well as theoretical genetics, impacting genetic engineering, gene therapy, and breeding programs to improve plant and animal resources.