In insects,20-hydroxyecdysone(20E)and insulin-like growth factor-like peptides(IGFLPs)regulate the development o f imaginal discs.However,how IGFLPs are up-regulated to impact the development of the pupal wing disc is...In insects,20-hydroxyecdysone(20E)and insulin-like growth factor-like peptides(IGFLPs)regulate the development o f imaginal discs.However,how IGFLPs are up-regulated to impact the development of the pupal wing disc is still unclear.In this study,we investigated the expression regulation of IGFLP in the pupal wing disc of silkworm,Bombyx mori.We confirmed that B.mori IGFLP(BmIGFLP)was mainly expressed in the pupal wing disc and the expression of BmIGFLP could be significantly induced by 20E.Bioinformatics analysis of BmIGFLP promoter sequence revealed three m-regulation elements(CREs)of signal transducer and activator of transcription(STAT),which is a key component in the Janus-activated kinase/STAT pathway.Luciferase activity assays showed that two CREs enhanced the transcriptional activity o f BmIGFLP.Electrophoretic mobility shift and chromatin immunoprecipitation assays demonstrated that BmSTAT proteins in the nuclear extracts o f B.mori pupal wing discs and BmN cells could only bind to the STAT CRE3,indicating that STAT CRE3 activated by BmSTAT enhances BmIGFLP expression at pupal stages.Although 20E could not enhance the expression of BmSTAT,20E enhanced the nucleus translocation o f BmSTAT to bind with the STAT CRE3 in the BmIGFLP promoter.The increase of transcriptional activity of the STAT CRE3 by overexpression of BmSTAT and addition o f 20E in BmN cells confirmed this result.Taken together,all data indicate that BmSTAT is one o f the transcription factors activating 20E-induced BmIGFLP expression in the pupal wing disc.展开更多
基金the National Basic Research Program of China(No.282012CB114603)the Scientific Research Cultivation Fund for Young Faculty of South China Normal University(Grant No.15KJ08).
文摘In insects,20-hydroxyecdysone(20E)and insulin-like growth factor-like peptides(IGFLPs)regulate the development o f imaginal discs.However,how IGFLPs are up-regulated to impact the development of the pupal wing disc is still unclear.In this study,we investigated the expression regulation of IGFLP in the pupal wing disc of silkworm,Bombyx mori.We confirmed that B.mori IGFLP(BmIGFLP)was mainly expressed in the pupal wing disc and the expression of BmIGFLP could be significantly induced by 20E.Bioinformatics analysis of BmIGFLP promoter sequence revealed three m-regulation elements(CREs)of signal transducer and activator of transcription(STAT),which is a key component in the Janus-activated kinase/STAT pathway.Luciferase activity assays showed that two CREs enhanced the transcriptional activity o f BmIGFLP.Electrophoretic mobility shift and chromatin immunoprecipitation assays demonstrated that BmSTAT proteins in the nuclear extracts o f B.mori pupal wing discs and BmN cells could only bind to the STAT CRE3,indicating that STAT CRE3 activated by BmSTAT enhances BmIGFLP expression at pupal stages.Although 20E could not enhance the expression of BmSTAT,20E enhanced the nucleus translocation o f BmSTAT to bind with the STAT CRE3 in the BmIGFLP promoter.The increase of transcriptional activity of the STAT CRE3 by overexpression of BmSTAT and addition o f 20E in BmN cells confirmed this result.Taken together,all data indicate that BmSTAT is one o f the transcription factors activating 20E-induced BmIGFLP expression in the pupal wing disc.
