Juvenile hormone-controlled vitellogenin synthesis in Locusta migratoria fat body: Hormonal induction in vivo☆

[摘要] Biosyntheticprocessesrelatedtotheproductionofvitellogenin(yolkprecursorprotein)havebeenexaminedinthefatbodyofadultfemaleLocustamigratoria.Vitellogenin-producingcapacitywasassayedbyincubationoffatbodywith[3H]leucine,followedbyprecipitationfromthemediumwithspecificantiserum.Innormaldevelopment,vitellogeninsynthesisbeganataboutDay7afteremergenceandbecamemaximalataboutDay13,whenthisproteinaccountedfor60%ofthetotalfatbodyproteinoutput.Theproductionofotherproteinsincreasedtoalesserextent,becomingmaximalataboutDay6.TheincorporationofuridineintofatbodyRNArosetoamaximumatDay8,whichcoincidedwithamarkedincreaseintissueRNAcontent.TheDNAcontentinadultfemalefatbodyapproximatelydoubledbetweenDays3and8.Vitellogeninsynthesis,andtheincreasesinRNAandDNA,werepreventedbyremovalofthecorporaallata(thesourceofjuvenilehormone).Inallatectomizedlocusts,vitellogeninsynthesiswasinducedbyJHorananalog,ZR-515.Appliedtopicallyinacetone,thesegavesteepdose-responsecurves,half-maximalat75and150μg,respectively.AfterasingletreatmentwithZR-515,fatbodyvitellogeninproductionroseslowlyduring48hr,thensteeplytoamaximumat72hr,butafterdecayofthiseffectduring10days,asecondapplicationofZR-515inducedrenewedsynthesiswithlittleinitiallag.Hormonetreatmentproducedasmallerincreaseintheoutputofotherproteins,andanincreaseinincorporationintoRNAwhichprecededthemajorriseinvitellogeninsynthesis.Malefatbodyproducedlittleornovitellogenin.TheseresultsareconsistentwithactionofJHatthegenelevel.

[学科分类] 生物科学（综合）