title: Juvenile hormone regulates vitellogenin gene expression through insulin-like peptide signaling pathway in the red flour beetle, Tribolium castaneum.
abstract: Our recent studies identified juvenile hormone (JH) and nutrition as the two key signals that regulate vitellogenin (Vg) gene expression in the red flour beetle, Tribolium castaneum. Juvenile hormone regulation of Vg synthesis has been known for a long time in several insects, but the mechanism of JH action is not known. Experiments were conducted to determine the mechanism of action of these two signals in regulation of Vg gene expression. Injection of bovine insulin or FOXO double-stranded RNA into the previtellogenic, starved, or JH-deficient female adults increased Vg mRNA and protein levels, thereby implicating the pivotal role for insulin-like peptide signaling in the regulation of Vg gene expression and possible cross-talk between JH and insulin-like peptide signaling pathways. Reduction in JH synthesis or its action by RNAi-mediated silencing of genes coding for acid methyltransferase or methoprene-tolerant decreased expression of genes coding for insulin-like peptides (ILPs) and influenced FOXO subcellular localization, resulting in the down-regulation of Vg gene expression. Furthermore, JH application to previtellogenic female beetles induced the expression of genes coding for ILP2 and ILP3, and induced Vg gene expression. FOXO protein expressed in baculovirus system binds to FOXO response element present in the Vg gene promoter. These data suggest that JH functions through insulin-like peptide signaling pathway to regulate Vg gene expression.
authors: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, Kentucky 40546.
authors: Zhentao
authors: Z
authors: Sheng
authors: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, Kentucky 40546.
authors: Jingjing
authors: J
authors: Xu
authors: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, Kentucky 40546.
authors: Hua
authors: H
authors: Bai
authors: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, Kentucky 40546.
authors: Fang
authors: F
authors: Zhu
authors: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, Kentucky 40546. Electronic address: rpalli@uky.edu.
authors: Subba R
authors: SR
authors: Palli
mesh_terms: D000818:Animals; D001483:Base Sequence; D001517:Coleoptera; D017931:DNA Primers / Q000235:genetics; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D005786:Gene Expression Regulation; D020868:Gene Silencing; D007328:Insulin / Q000378:metabolism*; D007605:Juvenile Hormones / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034622:RNA Interference; D015398:Signal Transduction; D014819:Vitellogenins / Q000096:biosynthesis*
chemical_list: D017931:DNA Primers; D051858:Forkhead Transcription Factors; D007328:Insulin; D007605:Juvenile Hormones; D010455:Peptides; D011506:Proteins; D014819:Vitellogenins; D051057:Proto-Oncogene Proteins c-akt