Poly synthetase spermatogenic cells

Cytoplasmic Poly(ADP-Ribose) Synthetase in Rat Spermatogenic Cells... 

The enzyme has been found ubiquitously in the nuclei of a great variety of eukaryotic cells, including human [11] and plant [12]. However, three previous studies have presented evidence that the enzyme is also localized in the cytoplasm. Roberts et al. [13] have found the enzyme associated with polysomes and ribosomes of HeLa cells. A poly(ADP-ribose) synthetase was also reported to occur in rat liver mitochondria [14]. More recently we found a significant level of enzymatic activity associated with testis mitochondria [15, 16]. The present paper is a follow-up of this study and it presents evidence that after the nuclear fraction, the most important level of poly(ADP-ribose) synthetase in spermatogenic cells is associated with the micro-somal-ribosomal fraction. 

Qermont and Perey [26] have shown that after birth, there is a good chronological relationship between the age of the rat and the type of spermatogenic cells present in the seminiferous tubules. This particular situation can be used to determine the type of spermatogenic cell in which poly(ADP-ribose) synthetase appears associated with the microsomal-ribosomal fraction. Accordingly, this cellular fraction was isolated from testis of rats at different time intervals after birth and the activity of the enzyme was measured. As shown in Table 4, the peak of activity was obtained with rats of 24- to 30-days-old. Thereafter, the specific activity of the enzyme reached the lower adult level. 

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