A central role for cohesions in sister chromatid cohesion, formation of axial elements, and recombination during yeast meiosis

A multisubunit complex, called cohesin, containing Smc1p, Smc3p, Scc1p, and Scc3p, is required for sister chromatid cohesion in mitotic cells. We show here that Smc3p and a meiotic version of Scc1p called Rec8p are required f or cohesion between sister chromatids, for formation of axial elements, for reciprocal recombination, and for preventing hyperresection of double-stra nd breaks during meiosis. Both Rec8p and Smc3p colocalize with chromosome c ores independently of synapsis during prophase I and largely disappear from chromosome arms after pachytene but persist in the neighborhood of centrom eres until the onset of anaphase II. The eukaryotic cell's cohesion apparat us is required both for the repair of recombinogenic lesions and for chromo some segregation and therefore appears to lie at the heart of the meiotic p rocess.