The poly(ADP-ribosyl)ation system in the crustacean copepod Temora stylifera (Dana, 1853–1855) from a coastal area of the Mediterranean Sea: a new biomarker of the health status

The aim of the present study was to characterize, for the first time, the poly(ADP-ribosyl)ation system in the micro-crustacean copepod Temora stylifera, a widespread species in the coastal area of the Mediterranean Sea, and one of the dominant calanoid of the zooplankton assemblage in the Gulf of Naples. The analysis of endogenous poly(ADP-ribose) polymerases (PARPs) and poly (ADP-ribose) glycohydrolases’ (PARGs) expression, together with PARP activity, were studied in the eggs laid by the females collected during the peak of the seasonal population dynamic of this species. In parallel, PARP activity in the adult females and their produced eggs were also measured after exposure for 3 consecutive days to a cytotoxic phytoplankton diet, the dinoflagellate Alexandrium andersoni (ALEX). Females and eggs fed with a non-toxic diet, the dinoflagellate Prorocentrum minimum (PRO), were used as control. A specific T. stylifera PARP (TPARP) of about 50 kDa and a PARG enzyme of about 60 kDa were identified. PARP activity increased to about seven mU in both copepod females and eggs following exposure to ALEX, after 1 and 2 days of feeding, respectively. This biochemical response was mirrored by a decrease in female survival (69%) and egg hatching success (53%). We suppose that the increase of PARP activity is a response to oxidative stress and subsequent DNA damage, induced by ALEX diet on both copepod adults and on developing embryos. In conclusion, TPARP is suggested as a new and useful biomarker of health status in T. stylifera females and eggs.