A role for βFTZ-F1 in regulating ecdysteroid titers during post-embryonic development in Drosophila melanogaster

摘要

Variationsinecdysteroidtitersplaycrucialrolesinarthropodsbyinitiatingandregulatingmoltingandmetamorphosis.TherecentidentificationofgenescodingforcytochromeP450enzymesinvolvedinemDrosophila/emecdysteroidogenesisprovidesnewmoleculartoolstoinvestigatetheregulationofinsecthormoneproduction.Inthepresentstudy,weusedanenzymeimmunoassaytoshowthatthemoltinghormonetiterisstrictlycorrelatedwiththesteroidogeniccapacityoftheringgland.Atemporalcorrelationbetweendynamicsofecdysoneproductionandexpressionofgenesencodingsteroidogenicenzymeswasobservedduringthethirdinstar,suggestingthatthetimingofhormoneproductiondependsontranscriptionalregulationofthebiosyntheticenzymes.Usingclonalanalysis,levelsoftwosteroidogenicenzymes,Phantom(PHM)andDisembodied(DIB),wereshowntobeveryreducedinemftztranscriptionfactor1/em(emftz-f1/em)mutantringglandcellswhereastherewasnoeffectoftheemwithoutchildren/em(emwoc/em)mutation,suggestingthatFTZ-F1regulatesemphm/emandemdib/emexpression.SinceβFTZ-F1isthehomologofthevertebratesteroidogenicfactor1(SF1),whichplaysakeyroleinthedifferentiationofvertebratesteroidogenicorgansthroughtranscriptionalregulationofsteroidogenicenzymes,thisstudyemphasizesthestrongparallelsbetweeninsectsandvertebrateswithrespecttotheregulatorymechanismsofsteroidogenesis./p/div