The primary purpose of the present study was to investi-gate whether DNA replication at meiotic prophase also requires replication factors, especially proliferating cell nuclear antigen (PCNA). We cloned PCNA cDNAs (CoPCNA) from a cDNA library made from basidia of the basidiomycete,Coprinus cinereus. Interestingly, although CoPCNAis a single-copy gene in the genome, two di er-entPCNAcDNA species were isolated using degenerate primers and a meiotic cDNA library, and were designated asCoPCNA-aandCoPCNA-b. .
