Linked Life Data

9570766

Source:http://linkedlifedata.com/resource/pubmed/id/9570766

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1998-7-14
pubmed:abstractText
The eye primordium of the moth, Manduca sexta, shows two different developmental responses to ecdysteroids depending on the concentration to which it is exposed. Tonic exposure to moderate levels of 20-hydroxyecdysone (20E) or its precursor, ecdysone, are required for progression of the morphogenetic furrow across the primordium. Proliferation, cell-type specification and organization of immature ommatidial clusters occur in conjunction with furrow progression. These events can be reversibly started or stopped in cultured primordia simply by adjusting levels of ecdysteroid to be above or below a critical threshold concentration. In contrast, high levels of 20E cause maturation of the photoreceptors and the support cells that comprise the ommatidia. Ommatidial maturation normally occurs after the furrow has crossed the primordium, but premature exposure to high levels of 20E at any time causes precocious maturation. In such cases, the furrow arrests irreversibly and cells behind the furrow produce a well-formed, but miniature, eye. Precocious and catastrophic metamorphosis occurs throughout such animals, suggesting that ecdysteroids control development of other tissues in a manner similar to the eye. The threshold concentrations of 20E required for furrow progression versus ommatidial maturation differ by about 17-fold. This capacity to regulate distinct phases of development by different concentrations of a single hormone is probably achieved by differential sensitivity of target gene promoters to induction by the hormone-bound receptor(s).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0950-1991
pubmed:author
pubmed:issnType
Print
pubmed:volume
125
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2009-18
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Ecdysteroids govern two phases of eye development during metamorphosis of the moth, Manduca sexta.
pubmed:affiliation
Department of Zoology, University of Washington, BOX 351800, Seattle, WA 98195-1800, USA. champd@zoology.washington.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't