Show simple item record Tobler, A Nijhout, HF
dc.coverage.spatial United States 2011-06-21T17:31:31Z 2010-05-19
dc.identifier.citation PLoS One, 2010, 5 (5), pp. e10723 - ?
dc.description.abstract BACKGROUND: Insulin and ecdysone are the key extrinsic regulators of growth for the wing imaginal disks of insects. In vitro tissue culture studies have shown that these two growth regulators act synergistically: either factor alone stimulates only limited growth, but together they stimulate disks to grow at a rate identical to that observed in situ. It is generally thought that insulin signaling links growth to nutrition, and that starvation stops growth because it inhibits insulin secretion. At the end of larval life feeding stops but the disks continue to grow, so at that time disk growth has become uncoupled from nutrition. We sought to determine at exactly what point in development this uncoupling occurs. METHODOLOGY: Growth and cell proliferation in the wing imaginal disks and hemolymph carbohydrate concentrations were measured at various stages in the last larval instar under experimental conditions of starvation, ligation, rescue, and hormone treatment. PRINCIPAL FINDINGS: Here we show that in the last larval instar of M. sexta, the uncoupling of nutrition and growth occurs as the larva passes the critical weight. Before this time, starvation causes a decline in hemolymph glucose and trehalose and a cessation of wing imaginal disks growth, which can be rescued by injections of trehalose. After the critical weight the trehalose response to starvation disappears, and the expression of insulin becomes decoupled from nutrition. After the critical weight the wing disks loose their sensitivity to repression by juvenile hormone, and factors from the abdomen, but not the brain, are required to drive continued growth. CONCLUSIONS: During the last larval instar imaginal disk growth becomes decoupled from somatic growth at the time that the endocrine events of metamorphosis are initiated. These regulatory changes ensure that disk growth continues uninterrupted when the nutritive and endocrine signals undergo the drastic changes associated with metamorphosis.
dc.format.extent e10723 - ?
dc.language eng
dc.language.iso en_US en_US
dc.relation.ispartof PLoS One
dc.relation.isversionof 10.1371/journal.pone.0010723
dc.subject Abdomen
dc.subject Animals
dc.subject Brain
dc.subject Carbohydrates
dc.subject Cell Proliferation
dc.subject Food
dc.subject Gene Expression Regulation, Developmental
dc.subject Glucose
dc.subject Hemolymph
dc.subject Injections
dc.subject Juvenile Hormones
dc.subject Larva
dc.subject Manduca
dc.subject Neuropeptides
dc.subject Organ Size
dc.subject RNA, Messenger
dc.subject Receptor, Insulin
dc.subject Starvation
dc.subject Trehalose
dc.subject Wings, Animal
dc.title A switch in the control of growth of the wing imaginal disks of Manduca sexta.
dc.title.alternative en_US
dc.type Journal Article
dc.description.version Version of Record en_US 2010-5-19 en_US
duke.description.endpage e10723 en_US
duke.description.issue 5 en_US
duke.description.startpage e10723 en_US
duke.description.volume 5 en_US
dc.relation.journal Plos One en_US
pubs.issue 5
pubs.organisational-group /Duke
pubs.organisational-group /Duke/Trinity College of Arts & Sciences
pubs.organisational-group /Duke/Trinity College of Arts & Sciences/Biology
pubs.publication-status Published online
pubs.volume 5
dc.identifier.eissn 1932-6203

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