Hyperploidy of embryonic fibroblasts derived from Parp-1 knockout mouse

Various studies show that poly(ADP-ribose) polymerase-1 (Parp-1) is involved in genomic stability. We previously established Parp-1 knockout (Parp-1-1-) mice by disrupting Parp-1 exon 1. Parp-1-1- and Parp-1+/+ embryonic fibroblasts were isolated and they became immortalized spontaneously after two months of culture. Parp-1-1- embryonic fibroblasts showed extensive hyperploidy compared to Parp-1+1+ counterparts, and most of the cells contained a single nucleus. These results suggest that disruption of Parp-1 could result in the perturbation of chromosomal ploidy control through endoreduplication.