Changes of acid phosphatase content and activity in the fat body and the hemolymph of the flesh fly Neobellieria (sarcophaga) bullata during metamorphosis

György Csikós, Miklós Sass

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Changes in the specific and total activity of the lysosomal marker enzyme acid phosphatase (Acph) and in the amount of enzyme protein were examined in the fat body and the hemolymph from the last Jarval molt to the larval-pupal apolysis. The specific activity showed minor changes during the last larval period. In contrast, the total activity of the enzyme was low during the feeding period and higher during the wandering stage and strikingly increased at the time of puparium formation. We purified a protein having para-nitrophenyl phosphate phosphatase (Acph) activity and raised antisera against it. The amount of Acph protein in the fat body and hemolymph was examined using an ELISA. The specific Acph content showed little variation, but the total amount of the enzyme protein showed a stepwise increase in both organs during last larval stage and was markedly elevated in the pupal stage in the fat body. In contrast, a considerable decrease in the amount of Acph protein was observed in the hemolymph during this period. These data were in agreement with immunohistochemical observations showing an accumulation of the enzyme protein in fat body cells during the prepupal stage with a concomitant disappearance of the enzyme from the hemolymph. Inhibition of ecdysteroid secretion by water stress prevented the changes both in total enzyme activity and in the amount of Acph protein. However, Acph protein content and enzyme activity could be restored when the water stress was followed by a 20-hydroxyecdysone (20-HE) treatment. Taken together, our data show that Acph is secreted by fat body cells into the hemolymph during the larval stage, where it is stored in an inactive form. Increase in the 20-HE titer at the end of last larval stage reverses this process, and the enzyme is taken up by the fat body cells, where it becomes activated and appears in auto- and heterophagic vacuoles.

Original languageEnglish
Pages (from-to)369-390
Number of pages22
JournalArchives of Insect Biochemistry and Physiology
Volume34
Issue number3
DOIs
Publication statusPublished - Jan 1 1997

    Fingerprint

Keywords

  • 20-hydroxyecdysone
  • Acid phosphatase
  • Fat body
  • Hemolymph
  • Secretion
  • Sequestration

ASJC Scopus subject areas

  • Physiology
  • Biochemistry
  • Insect Science

Cite this