Wijeratne Asela J, Chen Changbin, Zhang Wei, Timofejeva Ljudmilla, Ma Hong
Intercollege Graduate Program in Plant Physiology, The Pennsylvania State University, University Park, PA 16802, USA.
Mol Biol Cell. 2006 Mar;17(3):1331-43. doi: 10.1091/mbc.e05-09-0902. Epub 2006 Jan 4.
Recent studies of meiotic recombination in the budding yeast and the model plant Arabidopsis thaliana indicate that meiotic crossovers (COs) occur through two genetic pathways: the interference-sensitive pathway and the interference-insensitive pathway. However, few genes have been identified in either pathway. Here, we describe the identification of the PARTING DANCERS (PTD) gene, as a gene with an elevated expression level in meiocytes. Analysis of two independently generated transferred DNA insertional lines in PTD showed that the mutants had reduced fertility. Further cytological analysis of male meiosis in the ptd mutants revealed defects in meiosis, including reduced formation of chiasmata, the cytological appearance of COs. The residual chiasmata in the mutants were distributed randomly, indicating that the ptd mutants are defective for CO formation in the interference-sensitive pathway. In addition, transmission electron microscopic analysis of the mutants detected no obvious abnormality of synaptonemal complexes and apparently normal late recombination nodules at the pachytene stage, suggesting that the mutant's defects in bivalent formation were postsynaptic. Comparison to other genes with limited sequence similarity raises the possibility that PTD may present a previously unknown function conserved in divergent eukaryotic organisms.
最近对芽殖酵母和模式植物拟南芥减数分裂重组的研究表明，减数分裂交叉（COs）通过两条遗传途径发生：干涉敏感途径和干涉不敏感途径。然而，在这两条途径中鉴定出的基因都很少。在这里，我们描述了“分离舞者”（PTD）基因的鉴定，该基因在减数分裂细胞中表达水平升高。对PTD中两个独立产生的转移DNA插入系的分析表明，突变体的育性降低。对ptd突变体雄性减数分裂的进一步细胞学分析揭示了减数分裂缺陷，包括交叉形成减少，交叉的细胞学表现。突变体中残留的交叉随机分布，表明ptd突变体在干涉敏感途径中的CO形成存在缺陷。此外，对突变体的透射电子显微镜分析在粗线期未检测到联会复合体的明显异常和明显正常的后期重组结节，这表明突变体在二价体形成中的缺陷是突触后缺陷。与其他序列相似性有限的基因进行比较，增加了PTD可能具有在不同真核生物中保守的先前未知功能的可能性。
