Coprinus cinereus DNA ligase I during meiotic development.

DNA ligase I is thought to be essential for DNA replication, repair and recombination, at least in the mitotic cell cycle, but whether this is also the case during the meiotic cell cycle is still obscure. To investigate the role of DNA ligase I during the meiotic cell cycle, we cloned the Coprinus cinereus DNA ligase I cDNA (CcLIG1). Northern blotting analysis indicated that CcLIG1 is expressed not only in the premeiotic S-phase but also during the meiotic cell cycle itself. Especially, intense signals were observed in the leptotene and zygotene stages. Western blotting analysis indicated that CcLIG1 is expressed through the meiotic cell cycle and immunofluorescence also showed CcLIG1 protein staining in meiotic cells. Interestingly, the patterns was similar to that for the C. cinereus proliferating cell nuclear antigen gene (CcPCNA) and immunoprecipitation analysis suggested that CcPCNA binds to CcLIG1 in crude extracts of meiotic prophase I tissues. Based on these observations, relationships and roles during the meiotic cell cycle are discussed.