Structural and Functional Studies of Nuclear Organization, Chromatin and Chromosome Behaviour during Nuclear Division

我们将研究AHOP 2基因在模式植物拟南芥中的作用，以破译它在协调染色体配对和遗传交换中的功能。我们将研究AHOP 2是否经历了影响其功能的化学修饰，并寻找调节其活性的伴侣蛋白。ahop 2 -1突变体表现出异常的减数分裂结构，我们将努力表征这些结构的蛋白质。我们还将描述减数分裂染色质的特征，以与相邻细胞层的特征进行比较。 染色体配对和遗传交换是减数分裂的基本特征，减数分裂是核分裂的特殊形式，利用这些过程来确保染色体数目从二倍体到单倍体的平衡减少。单倍体减数分裂产物分化产生参与有性生殖的精子和卵子。相互的基因交换必须精确地进行。太少的严格性导致不适当的交换;太多的严格性导致交换数量不足;两种情况都导致产生遗传不平衡的染色体组。 我们的团队将由两名首席研究员，一名50%的时间研究助理，3名研究生和6-8名本科生组成。我们的研究将利用广泛的显微镜和成像，以及遗传和分子技术来研究AHOP 2在单倍体和二倍体植物中的功能。我们也将使用生物化学和基因组技术来描述与从营养期到减数分裂程序的过渡相关的染色质重塑。我们将利用的技术和相关技能也用于临床，基础和应用研究实验室以及工业。在我们的实验室培训的学生将能够为加拿大经济的知识和技术驱动的部门做出贡献。 减数分裂是有性生殖生物生命周期中的一个关键过程，扰动可导致生育力降低和出生缺陷。虽然减数分裂过程中染色体的运动早已被记录在案，但控制配对并确保交换精确完成的分子事件尚未完全了解。我们的工作应该有助于确定配对和交换的分子组成部分，并阐明AHOP 2在这些过程中的作用。同样，我们的研究可以通过调节交换的严格性来增强植物育种计划，从而使所需的基因从相关的野生物种渗入栽培物种。 由于减数分裂是一个保守的过程，我们研究的植物中获得的知识不仅有助于农业，而且有助于更好地了解人类出生缺陷的起源。最后，许多减数分裂蛋白也是基因组维护和修复所必需的;因此，我们的研究可能会导致对基因组完整性和DNA修复的更深入了解。

We will investigate the role of the AHOP2 gene in the model plant, Arabidopsis thaliana, to decipher how it functions in coordinating chromosome pairing and genetic exchange. We will examine whether AHOP2 undergoes chemical modifications that affect its function, and look for partner proteins that modulate its activities. The ahop2-1 mutant exhibits aberrant meiotic structures and we will strive to characterize the proteins that make up these structures. We also will characterize meiotic chromatin features for comparisons to those of the neighboring cell layer.     Chromosome pairing and genetic exchange are essential features of meiosis, the specialized form of nuclear division that uses these processes to ensure a balanced reduction of the chromosome number from diploid to haploid. The haploid meiotic products differentiate to produce the sperm and eggs that can participate in sexual reproduction. Reciprocal genetic exchange must be done precisely. Too little stringency results in inappropriate exchanges; too much stringency leads to inadequate numbers of exchanges; both scenarios lead to the production of genetically imbalanced chromosome sets.     Our team will consist of two Principal investigators, one 50%-time Research Associate, 3 graduate students and 6-8 undergraduates. Our research will utilize a broad range of microscopy and imaging, and genetic and molecular techniques to examine the function of AHOP2 in haploid and diploid plants. We also will use biochemical and genomic technologies to describe the chromatin remodeling associated with the transition from the vegetative to the meiotic program. The techniques and related skills we will utilize also are used in clinical, basic and applied research labs, as well as in industry. Students trained in our labs will be able to contribute to the knowledge and technology-driven sectors of the Canadian economy.      Meiosis is a critical process in the lifecycle of sexually reproducing organisms, and perturbations can lead to reduced fertility and birth defects. While chromosome movements during meiosis have long been documented, the molecular events that control pairing and ensure that exchange is done precisely are not yet fully understood. Our work should help identify molecular components of pairing and exchange and elucidate the role of AHOP2 in these processes. As well, our studies could enhance plant-breeding programs by allowing the stringency of exchange to be modulated to allow introgression of desirable genes into cultivated species from related wild species.     As meiosis is a conserved process, knowledge gained in the plants we study not only can contribute to agriculture, but also can contribute to a better understanding of the origins of birth defects in humans. Finally, many meiotic proteins also are essential to genome maintenance and repair; thus our research may lead to a deeper understanding of genome integrity and DNA repair.