Changes in trehalase activity and trehalose level during Ascaris suum (Nematoda) embryogenesis

Summary The levels of trehalose and the activity of trehalase during the development of Ascaris suum eggs were investigated. The level of trehalose in the zygote was high (2.96 ± 0.07 mg/g). During cleavage of eggs, it decreased (0.91 ± 0.35 mg/g). A higher concentration of the sugar was recorded at the blastula and during gastrulation, but it did not reach the uncleaved eggs level. In the early motile larvae, the concentration of trehalose was high (4.58 ± 2.01 mg/g). It decreased with development of L₁ larvae (3.10 ± 1.47 mg/g). A rapid increase in trehalose reserves was observed between the L₁ and L₂ stages. The highest content of trehalose was found in invasive L₂ larvae (5.78 ± 1.39 mg/g). The activity of trehalase at the zygote stage was high (560.22 ± 322.31 U/mg). It decreased at the beginning of cleavage. It was the lowest at the 4–6-cell stage (189.76 ± 114.97 U/mg). An increase in the enzyme activity occurred after reaching the blastula stage (348.44 ± 343.34 U/mg). The highest trehalase activity was recorded during the L₁ larvae stage (635.72 ± 251.16 U/mg). The activity of that enzyme was about three times lower in the invasive stage larvae than in the L₁ larvae.