Mechanisms of meiotic recombination

减数分裂重组的机制减数分裂、同源配对、重组和染色体分离过程是有性繁殖和遗传信息忠实遗传的基础。配对是重组的基础，减数分裂交换决定了分离模式。因此，交换是减数分裂中必不可少的过程。众所周知，由交换事件决定的遗传连锁与DNA长度成正比。然而，单位长度DNA的交换次数因染色体的不同而不同。并产生了交换的减数分裂模式。减数分裂模式在门内和物种之间高度保守。这种保守表明这种模式具有基本的生物学意义，并提出了几个假说来解释为什么某些区域的减数分裂模式的交换频率较高或较低。在秀丽线虫中，减数分裂模式已被广泛描述，每百万碱基对的交叉模式可以在染色体上变化多达十倍。rec-1基因的突变消除了减数分裂模式，生成与物理图谱类似的遗传图谱。如果这种突变的存在证明减数分裂模式是受基因控制的，并为研究该模式的分子基础提供了可能性。在这项提议中，我申请资金来表征rec-1基因产物。为了确定rec-1基因产物的功能机制，我们将产生额外的等位基因，以扩展我们对基因的表型表征，调查基因相互作用，确定基因产物的细胞定位，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.