Rad21/Rec8 is an important component and key regulator of cohesins. A RAD21-like gene from rice (Oryza sativa L. ssp. japonica) has been cloned and termed OsRAD21-1. OsRAD21-1 is a single-copy gene in the rice genome and is expressed in the entire plant. OsRad21-1 consists of 1055 amino acid residues and is the largest of the Rad21/Rec8 family identified to date. Based on sequence similarity comparison with other members of this family and gene expression patterns, it is concluded that OsRad21 is a rice orthologue of yeast Rad21.