Changes in esterases during early embryonic development of Barytelphusa guerini (H. Milne Edwards)

Abstract

Quantitative and qualitative changes in the levels of activity of esterases are studied in five stages of developing embryos of the freshwater crab Barytelphusa guerini. Esterase activity levels increase enormously as development progresses. Electrophoresis on 7.5% polyacrylamide disc gels reveals seven zones of esterase active bands. Only two of the seven zones of esterases are present in all five stages. These bands show an increase in their activity in stages III–V. Substrate specificity and inhibitor sensitivity of the enzymes were used to classify esterases. The twofold serial dilution technique was employed to estimate the relative proportion of each esterase band observed during electrophoresis. Heat denaturation studies indicate an increase in the thermal stability of the enzyme as development progresses.