Expression of sex steroid hormone-related genes in the embryo of the leopard gecko.pdf

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1、Availableonlineatwww.sciencedirect.comGeneralandComparativeEndocrinology155(2008)70–78www.elsevier.com/locate/ygcenShortCommunicationExpressionofsexsteroidhormone-relatedgenesintheembryooftheleopardgeckoDaisukeEndo,Yoh-IchiroKanaho,MinKyunPark*DepartmentofBiologicalSciences,GraduateScho

2、olofScience,TheUniversityofTokyo,7-3-1Hongo,Bunkyo,Tokyo113-0033,JapanReceived28November2006;revised4April2007;accepted9April2007Availableonline21April2007AbstractSexsteroidhormonesareknowntoplayacentralroleinvertebratesexdeterminationanddifferentiation.However,thetissuesinwhichtheyarepr

3、oducedorreceivedduringdevelopment,especiallyaroundtheperiodofsexdeterminationofthegonads,haverarelybeeninvestigated.Inthisstudy,weidentifiedthecDNAsequence,includingthefull-lengthofthecodingregionofcholesterolside-chaincleavageenzyme(P450scc),fromtheleopardgecko;alizardwithtemperature-de

4、pendentsexdetermination.Embryonicexpressionanal-ysisoftwosteroidogenicenzymes,P450sccandP450aromatase(P450arom),andfoursexsteroidhormonereceptors,androgenreceptor,estrogenreceptoraandb,andprogesteronereceptor,wassubsequentlyconducted.mRNAexpressionofbothsteroidogenicenzymeswasobservedin

5、thebrainandgonadspriortothetemperature-sensitiveperiodofsexdetermination.ThemRNAsofthefoursexsteroidhormonereceptorswerealsodetectedinthebrainandgonadsatallstagesexamined.Theseresultssuggesttheexistenceofagonad-inde-pendentsexsteroidhormonesignalingsysteminthedevelopingleopardgeckobrain

6、.Ó2007ElsevierInc.Allrightsreserved.Keywords:Reptile;Leopardgecko;Temperature-dependentsexdetermination;Sexsteroidhormone;P450scc1.Introductionofmalegonad-specificgenes(Couseetal.,1999).Althoughgonadogenesisisessentiallyresistanttoexogenoushor-Thefirstsexdeterminationswitchisextremelydive

7、rsemonesineutherianmammals,exogenousestrogencanamongvertebrates.TheexistenceofSryonthemale-spe-induceincompletesexreversalinmarsupialsandbirds.cificsexchromosomecreatesthegonadsofembryotestesForexample,thetammarwallaby,amarsupialspecies,inmammals(Sinclairetal.,1990;Koopmanetal.,