Poly[ADP-ribose] polymerases modify various nuclear proteins by poly(ADP-ribosyl)ation, a post-translational modification synthesized after DNA damage that appears as an obligatory step in a detection/signaling pathway leading to the reparation of DNA strand breaks and programmed cell death. NAD(+) + (ADP-D-ribosyl)n-acceptor = nicotinamide + (ADP-D-ribosyl)n+1-acceptor + H(+). L-aspartyl-[protein] + NAD(+) = 4-O-(ADP-D-ribosyl)-L-aspartyl-[protein] + nicotinamide L-glutamyl-[protein] + NAD(+) = 5-O-(ADP-D-ribosyl)-L-glutamyl-[protein] + nicotinamide Associated with condensing chromosomes. Expressed throughout the head and tail, in germ cells and somatic cells. Detected at all stages (PubMed:14706351, PubMed:19104912). Expressed at low level in embryos compared to larvae (PubMed:14706351). Peaks in young adults (PubMed:14706351). By irradiation (PubMed:14706351, PubMed:19104912). This induction is dependent on hus-1 (PubMed:14706351).