A specific nuclear protein and poly(ADPribose)transferase activity in lizard oviduct during the reproductive cycle

A specific nuclear protein (SNP) appears in the oviduct of the lizard, Podarcis s. sicula Raf., during the recovery phase of the breeding cycle. The protein has a low molecular weight (9.9 kDa), a high electrophoretic mobility and a peculiar amino acid composition. It seems to be regulated by estradiol which, in this species, is involved in oviduct stimulation. Nuclear poly(ADPribose)transferase activity increases in the oviduct as the organ grows, and it peaks upon morphological maturation. Thereafter, as the oviduct becomes secretory, the enzyme returns to basal level. A transient increase of poly(ADPribose)transferase precedes the appearance of SNP, which suggests that the two phenomena are related.