Fig. 1. Schematic representation of the AtSMC1 and AtSMC3 loci. Genomic maps showing the relative positions of AtSMC1, PTPG and AtSMC3, as well as cDNA fragments that were analyzed, are shown. The black boxes represent exons. Arrows (not drawn to scale) mark the position and orientation of primers used in this study. Broken arrows represent the main AtSMC1 and AtSMC3 transcriptional units. Bars separated by broken lines represent the cDNA fragment obtained from AtSMC1, PTPG, and an EST from GenBank. Bars, 0.4 kb.