Meiosis-specific component of some cohesin complex. Probably required during early meiosis for separation of sister chromatids and homologous chromosomes. Replaces RAD21 in premeiotic S phase (during early stages of prophase I), while RAD21 reappears in later stages of prophase I. May be involved in synapsis initiation and crossover recombination between homologous chromosomes. Belongs to the rad21 family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.