Linked Life Data

10876132

Source:http://linkedlifedata.com/resource/pubmed/id/10876132

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8-9
pubmed:dateCreated
2000-11-7
pubmed:abstractText
Larvae of the spruce budworm, Choristoneura fumiferana, infected with C. fumiferana entomopoxvirus (CfEPV) continue to feed and grow without undergoing metamorphosis and die as moribund larvae. The lethal dose (LD(50)) and lethal time (LT(50)) values for fourth instar larvae are 2.4 spheroids and 25.2 days, respectively. One hundred percent of the control fourth instar larvae, which were fed water instead of virus, pupated by 18 days post feeding (PF). Only 30% of the larvae that were fed the LD(50) dose and none of the larvae that were fed the LD(95) dose pupated by 18 days PF. Of the control larvae, 95% became adults by 24 days PF, whereas in the treated group only 2% of larvae that were fed the LD(50) dose and none of the larvae that were fed the LD(95) dose became adults by 24 days PF. Some of the virus-treated larvae died as either larval/pupal or pupal/adult intermediates. These phenotypic effects were similar to the larval/pupal and pupal/adult intermediates, resulting from treating larvae with juvenile hormone (JH) or its analogs, which suggests that EPV may cause such abnormalities by modulating JH and/or ecdysteroid titers. In untreated sixth instar larvae the JH titer decreased to low levels by 24 h after ecdysis and remained low throughout larval life. EPV-fed sixth instar larvae had 2112 pg/ml on day 0, 477 pg/ml on day 1 and 875 pg/ml on day 8 of the sixth instar. Control larvae contained 860 ng of ecdysteroids per ml hemolymph on day 8 of the sixth instar, whereas EPV-treated larvae of the same age (30 days PF) had only 107 ng of ecdysteroids per ml of hemolymph. Thus, EPV infection results in increased JH titer and decreased ecdysteroid titer. Northern hybridization analysis was performed using RNA isolated from control and EPV-fed larvae and cDNA probes for (i) juvenile hormone esterase (JHE), which is JH inducible, (ii) Choristoneura hormone receptor 3 (CHR3), which is ecdysteroid inducible, and (iii) larval specific diapause associated protein 1 (DAP1), whose expression is larval specific. EPV-treated larvae showed higher levels of JHE and DAP1 mRNA and lower levels of CHR3 mRNA, indicating that they had higher levels of JH and lower levels of ecdysteroids. Thus, our data show that EPV prevents metamorphosis by modulating ecdysteroid and JH levels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0965-1748
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
869-76
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Choristoneura fumiferana entomopoxvirus prevents metamorphosis and modulates juvenile hormone and ecdysteroid titers.
pubmed:affiliation
Great Lakes Forestry Centre, Canadian Forest Service, P6A 5M7, Sault Ste. Marie, Ont., Canada. rpalli@ncran.gc.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't