General esterases activity in the different body
tissues of adult females of 2-day and 13-day-old Schistocerca gregaria (Forskal)
were measured spectrophotometricaly and carboxylesterase and phosphotriesterase
were characterized by electrophoresis method. Esterase activities were studied
in the tissues of brain, fore-, mid-, hindgut and ovary of the two ages in the
presence of α-naphthyl acetate as a substrate and ethylenediamine tetraacetic
acid (EDTA) and profenofos as inhibitors. Spectrophotometric analysis indicated
that the esterase activity in adult S. gregaria tissues was
significantly higher in the tissues of mid-, foregut, ovary and brain of
2-day-old females than those of 13-day-old, respectively. Meanwhile, the
activity was greater in the hindgut tissue of 13-day-old females than in
2-day-old ones. Non-denaturing polyacrylamide gel electrophoresis revealed
differences in isozyme composition. Three to ten esterase bands were detected
in the different body tissues of the two ages of adult females. These bands were
characterized as phosphotriesterase and carboxylesterase by using the two
inhibitors. Bands Est-1, Est-2, Est-3 and Est-6 were found to be
carboxylesterase in the different tissues, while band Est-4 was only detected
to be phosphotriesterase.