The role of low levels of juvenile hormone esterase in the metamorphosis of Manduca sexta.

Journal Article (Journal Article)

The activity of juvenile hormone esterase (JHE) in feeding fifth instar larvae of Manduca sexta increases gradually with larval weight and rises to a peak after larvae pass the critical weight when juvenile hormone secretion ceases. Starvation of larvae of Manduca sexta (L.) that had exceeded the critical weight inhibited peak levels of JHE, but did not delay entry into the wandering stage when larvae leave the plant in search of a pupation site. This suggests that peak levels of JHE may not be essential for the normal timing of metamorphosis. Starved larvae pupated normally, indicating the peak of JHE was not necessary for a morphologically normal pupation. Treatments of larvae with the selective JHE inhibitor O-ethyl-S-phenyl phosphoramidothiolate (EPPAT) that began immediately after larvae achieved the critical weight (6.0 to 6.5 grams for our strain of Manduca) delayed entry into the wandering stage. By contrast, EPPAT treatment of larvae at weights above 8.0 g had no effect on the subsequent timing of the onset of wandering. Therefore, although the normal timing of the onset of wandering does not require peak levels of JHE, it requires low to moderate levels of JHE to be present until larvae reach a weight of about 8.0 g.

Full Text

Duke Authors

Cited Authors

  • Browder, MH; D'Amico, LJ; Nijhout, HF

Published Date

  • January 2001

Published In

Volume / Issue

  • 1 /

Start / End Page

  • 11 -

PubMed ID

  • 15455071

Pubmed Central ID

  • PMC355895

Electronic International Standard Serial Number (EISSN)

  • 1536-2442

International Standard Serial Number (ISSN)

  • 1536-2442

Language

  • eng