Mechanisms of meiotic recombination

减数分裂的机制减数分裂、同源配对、重组和染色体分离的过程是有性生殖和遗传信息忠实遗传的基础。 配对对于重组是必不可少的，减数分裂交换决定分离模式。 因此交换是减数分裂的一个重要过程。 众所周知，由交叉事件确定的遗传连锁与DNA长度成比例。 然而，每单位长度的DNA的交换数量因染色体的不同区域而异，并产生交换的“减数分裂模式”。 减数分裂模式在门内和种间是高度保守的。 保护表明，该模式具有基本的生物学重要性，并提出了几种假设来解释为什么某些地区的交叉频率较高或较低。 在秀丽隐杆线虫中，减数分裂模式已被广泛表征，并且每百万个碱基对的交换数量可以在染色体上变化多达10倍。 rec-1基因的突变消除了减数分裂模式，产生了与物理图谱相似的遗传图谱。 这种突变的存在证明了减数分裂模式是受遗传控制的，并提供了潜在的检查模式的分子基础。 在这份提案中，我请求资助描述rec-1基因产物。 为了确定rec-1基因产物发挥功能的机制，我们将产生额外的等位基因，以扩展我们对该基因的表型表征，研究基因相互作用，确定基因产物的细胞定位，并检查染色体结构中可能的改变。 我的研究计划的长期目标是更全面地了解控制减数分裂的基本遗传和分子过程，以及减数分裂模式的进化意义。

Mechanisms of Meiotic Recombination The processes of meiosis, homolog pairing, recombination and chromosome segregation are fundamental to sexual reproduction and faithful inheritance of genetic information.  Pairing is essential for recombination, and meiotic exchange determines segregation patterns.  Thus crossing over is an essential process in meiosis.  It is well known that genetic linkage as determined by crossover events is proportional to DNA length.  However, the number of crossovers per unit length of DNA varies for different regions of the chromosome, and generates the 'meiotic pattern' of crossing over.  Meiotic patterns are highly conserved within phyla and between species.  The conservation suggests that the pattern is of fundamental biological importance, and several hypotheses have been put forward to explain why the frequency of crossing over is higher or lower for certain regions.   In Caenorhabditis elegans, the meiotic pattern has been extensively characterized, and the number of crossovers per million base pairs can vary as much as ten-fold across the chromosome.  A mutation in the rec-1 gene eliminates the meiotic pattern, generating a genetic map similar to the physical map.   The existence of this mutation proves that the meiotic pattern is under genetic control, and provides the potential to examine the molecular basis of the pattern.   In this proposal, I am requesting funding to characterize the rec-1 gene product.  In order to determine the mechanism by which the rec-1 gene product functions, we will generate additional alleles in order to extend our phenotypic characterization of the gene, investigate gene interactions, determine the cellular localization of the gene product, and examine possible alterations in chromosome architecture.  The long-term goal of my research program is to understand more fully the fundamental genetic and molecular processes controlling meiosis, and the evolutionary significance of meiotic patterning.