Prothoracicotropic hormone regulates developmental timing and body size in Drosophila.
In insects, control of body size is intimately linked to nutritional quality as well as environmental and genetic cues that regulate the timing of developmental transitions. Prothoracicotropic hormone (PTTH) has been proposed to play an essential role in regulating the production and/or release of ecdysone, a steroid hormone that stimulates molting and metamorphosis. In this report, we examine the consequences on Drosophila development of ablating the PTTH-producing neurons. Surprisingly, PTTH production is not essential for molting or metamorphosis. Instead, loss of PTTH results in delayed larval development and eclosion of larger flies with more cells. Prolonged feeding, without changing the rate of growth, causes the overgrowth and is a consequence of low ecdysteroid titers. These results indicate that final body size in insects is determined by a balance between growth-rate regulators such as insulin and developmental timing cues such as PTTH that set the duration of the feeding interval.
McBrayer
Zofeyah
Z
The Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA.
Ono
Hajime
H
Shimell
MaryJane
M
Parvy
Jean-Philippe
JP
Beckstead
Robert B
RB
Warren
James T
JT
Thummel
Carl S
CS
Dauphin-Villemant
Chantal
C
Gilbert
Lawrence I
LI
O'Connor
Michael B
MB
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D049628:Body Size / Q000502:physiology*; D004330:Drosophila / Q000196:embryology / Q000254:growth & development*; D029721:Drosophila Proteins / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism; D007301:Insect Hormones / Q000494:pharmacology*; D007814:Larva / Q000254:growth & development; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000502:physiology
D029721:Drosophila Proteins; D007301:Insect Hormones; D009479:Neuropeptides; C009089:prothoracicotropic hormone