Journal
DEVELOPMENTAL BIOLOGY
Volume 325, Issue 2, Pages 341-350Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.ydbio.2008.10.016
Keywords
Juvenile hormone; Ecdysteroids; Insect metamorphosis; Tribolium castaneum; Kruppel homolog 1; Methoprene-tolerant; Broad; RNAi
Categories
Funding
- Program for Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN)
- Japan Society for the Promotion of Science
Ask authors/readers for more resources
Juvenile hormone (JH) prevents ecdysone-induced metamorphosis in insects. However, our knowledge of the molecular mechanisms of JH action is still fragmented. Kruppel homolog 1 (Kr-h1) is a JH-inducible transcription factor in Drosophila melanogaster (Minakuchi, C., Zhou, X., Riddiford, L.M., 2008b. Kruppel homolog 1 (Kr-h1) mediates juvenile hormone action during metamorphosis of Drosophila melanogaster. Mech. Dev. 125, 91-105). Analysis of expression of the homologous gene (TcKr-h1) in the beetle Tribolium castaneum showed that its transcript was continuously present in the larval stage but absent in the pupal stage, Artificial suppression of JH biosynthesis in the larval stage caused a precocious larval-pupal transition and a down-regulation of TcKr-h1 mRNA. RNAi-mediated knockdown of TcKr-h1 in the larval stage induced a precocious larval-pupal transition. In the early pupal stage, treatment with an exogenous JH mimic OHM) caused formation of a second pupa, and a rapid and large induction of TcKr-h1 transcription. JHM-induced formation of a second pupa was counteracted by the knockdown of TcKr-h1. RNAi experiments in combination with JHM treatment demonstrated that in the larval stage TcKr-h1 works downstream of the putative JH receptor Methoprene-tolerant (TcMet), and in the pupal stage it works downstream of TcMet and upstream of the pupal specifier broad (Tcbr). Therefore, TcKr-h1 is an early JH-response gene that mediates JH action linking TcMet and Tcbr. (C) 2008 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available