The Pitx homeobox gene in Bombyx mori: regulation of DH-PBAN neuropeptide hormone gene expression.
The diapause hormone-pheromone biosynthesis activating neuropeptide gene, DH-PBAN, is expressed exclusively in seven pairs of DH-PBAN-producing neurosecretory cells (DHPCs) on the terminally differentiated processes of the subesophageal ganglion (SG). To help reveal the regulatory mechanisms of cell-specific DH-PBAN expression, we identified a cis-regulatory element that regulates expression in DHPCs using the recombinant AcNPV-mediated gene transfer system and a gel-mobility shift assay. Bombyx mori Pitx (BmPitx), a bicoid-like homeobox transcription factor, binds this element and activates DH-PBAN expression. The BmPitx was expressed in various tissues, including DHPCs in the SG. Suppression of DH-PBAN expression by silencing of the BmPitx successfully induced non-diapaused eggs from a diapause egg producer. To the best of our knowledge, this report is the first to identify a neuropeptide-encoding gene as a target of the Pitx transcriptional regulator in invertebrates. Thus, it is tempting to speculate that functional conservation of Pitx family members on neuropeptide gene expression occurs through a "combinational code mechanism" in both vertebrate and invertebrate in neuroendocrine systems.
Shiomi
Kunihiro
K
Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan. shiomi@giptc.shinshu-u.ac.jp
Fujiwara
Yoshihiro
Y
Yasukochi
Yuji
Y
Kajiura
Zenta
Z
Nakagaki
Masao
M
Yaginuma
Toshinobu
T
D000818:Animals; D012831:Bombyx / Q000235:genetics*; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000502:physiology*; D005801:Genes, Homeobox / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D019476:Insect Proteins / Q000378:metabolism*; D007814:Larva; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D034622:RNA Interference / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
C092658:DH-PBAN precursor protein, Bombyx mori; D019476:Insect Proteins; D009479:Neuropeptides; D011498:Protein Precursors; D049452:Green Fluorescent Proteins