A central feature of meiosis is the pairing of homologous maternal and paternal chromosomes (‘homologues’) along their lengths^1,2,3. Recognition between homologues and their juxtaposition in space is mediated by axis-associated recombination complexes. Also, pairing must occur without entanglements among unrelated chromosomes. Here we examine homologue juxtaposition in real time by four-dimensional fluorescence imaging of tagged chromosomal loci at high spatio-temporal resolution in budding yeast. We discover that corresponding loci come together from a substantial distance (1.8 µm) and complete pairing in a very short time, about 6 min (thus, rapid homologue juxtaposition or RHJ). Homologue loci first move rapidly together (in 30 s, at speeds of roughly 60 nm s⁻¹) into an intermediate stage corresponding to canonical 400 nm axis coalignment. After a short pause, crossover/non-crossover differentiation (crossover interference) mediates a second short, rapid transition that ultimately gives close pairing of axes at 100 nm by means of synaptonemal complex formation. Furthermore, RHJ (1) occurs after chromosomes acquire prophase chromosome organization, (2) is nearly synchronous over thirds of chromosome lengths, but (3) is asynchronous throughout the genome. Finally, cytoskeleton-mediated movement is important for the timing and distance of RHJ onset and for ensuring its normal progression. General implications for local and global aspects of pairing are discussed.

减数分裂的一个中心特征是同源母系和父系染色体（“同源物”）沿其长度^1,2,3 配对。同源物之间的识别及其在空间中的并列是由轴相关重组复合物介导的。此外，配对必须在不相关的染色体之间没有纠缠。在这里，我们通过对出芽酵母中标记的染色体基因座进行四维荧光成像，以高时空分辨率实时检查同源物并列。我们发现相应的基因座从相当远的距离 （1.8 μm） 聚集在一起，并在很短的时间内完成配对，大约 6 分钟（因此，快速同源并列或 RHJ）。同源基因座首先快速移动到一起（在 30 秒内，速度约为 60 nm ^s-1）进入对应于典型 400 nm 轴共对齐的中间阶段。短暂暂停后，交叉/非交叉分化（交叉干扰）介导第二个短而快速的转变，最终通过突触复合物形成在 100 nm 处形成紧密配对的轴。此外，RHJ （1） 发生在染色体获得前期染色体组织之后，（2） 在染色体长度的三分之一上几乎同步，但 （3） 在整个基因组中是异步的。最后，细胞骨架介导的运动对于 RHJ 发作的时间和距离以及确保其正常进展很重要。讨论了配对对局部和整体方面的一般影响。