Localization of acid phosphatase activity in the testis of two teleostean species (Oreochromis niloticus and Odonthestes perugiae)

Abstract

Acid phosphatase (AcP) activity was investigated in the testes of two species of teleosts in two seasons: summer and winter. AcP activity was detected in Sertoli cells from tilapia (Oreochromis niloticus) only during the nonreproductive period of its annual cycle, corresponding to the winter months. In kingfish (Odonthestes perugiae), the enzymatic reaction was identified during the non-reproductive period (summer) in epithelial cells of the efferent ducts but not in Sertoli cells. These data suggest that the enzyme is involved in the absorption of residual spermatid cytoplasm and as well as in the removal of spermatozoa remaining after the reproductive period. In kingfish, this heterophagous function is carried out by the efferent duct cells and not by Sertoli cells.

Expression of acid phosphatase in the seminiferous epithelium of vertebrates

“…This phagocytic function appears to be hormone-independent (Chemes, 1986). This fact is corroborated by the conclusions of some studies in which some species including Oreochromis niloticus (Teleostei, Cichlidae) and Odonthestes perugiae (Teleostei, Atherinidae) showed AcP expression in the non-reproductive period (Porawski et al, 2004), whereas in other species such as Liolemus elongatus (Reptile, Squamata) AcP activity was detected only in the reproductive period (Grimalt et al, 1995).…”

“…AcP activity was similar in the testes of these four species studied, all of which were in their respective reproductive periods. According to Porawski et al (2004) in Nile tilapia (O. niloticus) and kingfish (Odonthestes perugiae), positive AcP activity was observed only in the non-reproductive period: winter (Nile tilapia) and summer (kingfish). This difference can be related to hormonal control of AcP expression in these organs.…”

“…In spite of these observations, it had been postulated that, in general, AcP activity is very important to the spermatogenetic process in vertebrates during the reproductive period as much as in the non-reproductive period. In germ cells during the reproductive period of some animals, the study of acid phosphatase has been principally related to the lysosomes of Sertoli cells (Niemi and Kormano, 1965;Hurk et al, 1974;Chemes, 1986;Porawski et al, 2004), the acrosome (Anderson, 1968;Sousa et al, 1988;Báo et al, 1989) and the axoneme (Anderson, 1968;Baccetti et al, 1971Baccetti et al, , 1973.…”

“…This finding indicates a prominent/significant autophagic function of this cell type in this tissue during the reproductive period in these species. It is well known that AcP activity is present in heterophagic lysosomes of Sertoli cells (Niemi and Kormano, 1965;Hurk et al, 1974;Chemes, 1986;Porawski et al, 2004). AcP and lysosomal contents of Sertoli cells are greater than those of germ cells, and the residual body disposal is probably initiated by autophagy and completed by Sertoli cell phagocytosis (Chemes, 1986).…”

“…The expression of this enzyme also has been studied in the testis. It is well known that AcP activity is present in the lysosomes of Sertoli cells, which have a heterophagic function (Niemi and Kormano, 1965;Hurk et al, 1974;Chemes, 1986;Porawski et al, 2004). In rats, the digestion of residual bodies is likely to begin with autophagy in spermatids and be completed with phagocytosis by Sertoli cells.…”