Molecular cloning of a prothoracicostatic peptide (PTSP) in the
larval brain of the silkworm, Bombyx mori
Y.-J. Hua 1,2 , Y.
Tanaka 2 & H.Kataoka 3
1 Inst. Nuclear-Agricult.
Sci., Zhejiang Univ., 310029 Hangzhou, China; 2 Lab of Bioactive
Substances, Natl. Inst. of Seircul. & Entomol. Sci., 305-8634
Tsukuba, Japan; 3 Dept. of Intergrated Biosci., Graduate School of
Frotier Sci., Tokyo Univ. 113-0032 Tokyo, Japan
Ecdysone secreted by
the prothoracic gland (PG) plays a central role in the insect
metamorphosis as molting hormone, which biosynthesis is considered
to be stimulated by prothoracicotropic hormone (PTTH). Recently,
we have identified a prothoracicostatic peptide (PTSP) from the
brain of the silkworm, Bombyx mori. PTSP strongly inhibited
ecdysteroidogenesis in the PGs of spinning larvae, and
simultaneous application of PTSP and PTTH to the PGs of the
feeding larvae inhibited the PTTH-stimulated ecdysteroidogenesis.
These results indicate the importance of PTSP in the regulation of
ecdysteroidogenesis. Using RT-PCR and 5’-RACE we have cloned PTSP
cDNA from B. mori brain. The predicted open reading frame encoded
288 amino acids including five repeats of PTSP and five other
structure-related peptides. Some related peptides also showed
prothoracicostatic activity in the in vitro bioassay. Northern
blot analysis indicated that PTSP gene is expressed mainly in the
Bombyx mori, ecdysteroidogenesis, prothoracicostatic
Copyright: The copyrights of
this original work belong to the authors (see right-most box in
title table). This abstract appeared in Session 19 – SOCIAL
INSECTS AND SERICULTURE Symposium and Poster Session, ABSTRACT
BOOK II – XXI-International Congress of Entomology, Brazil,
August 20-26, 2000.