Developmental expression and distribution of amphibian glutathione transferases

This work is aimed at detecting the expression and location of embryonic Bu fo bufo GST (bbGSTP1-1) and adult B. bufo GST (bbGSTP2-2) during toad devel opment, in order to assign a putative role to these enzymes also on the bas is of their compartmentalization and to verify whether during the premetamo rphic liver ontogeny the bbGSTP2-2 form appears. This study was also perfor med in the adult liver (the primary site of Pi class GST expression) and in the mature ovary, to discern if the embryonic form derives from maternal f orm. The results show that the embryos and the ovary express only bbGSTP1-1 . Moreover, bbGSTP1-1 distribution is the same both in the early embryos an d in the ovary: this strongly suggests that bbGSTP1-1 is of maternal origin . As development goes on, a wide distribution of bbGSTP1-1 all over the dif ferentiating organs is observed. The embryonic liver expresses exclusively the bbGSTP1-1 form, while the adult liver is highly positive only towards t he bbGSTP2-2 form. This implies that the switch towards the adult bbGSTP2-2 form occurs in metamorphic or postmetamorphic phases and that the detoxica tion metabolic requirements of the embryo may be completely fulfilled by th e bbGSTP1-1 isoenzyme. (C) 2001 Elsevier Science B.V. All rights reserved.