mRNAexpressionandDNAmethylationinthreekeygenesinvolvedincastedifferentiationinfemalehoneybees(Apismellifera)

Inhoneybee(Apismellifera)colonies,queensandworkersarealternativeformsoftheadultfemalehoneybeethatdevelopfromgeneticallyidenticalzygotesbutthatdependondifferentialnourishment.Queensandworkersdisplaydistinctmorphologies,anatomiesandbehavior,betterknownascastedifferentiation.Despitesomebasicinsights,theexactmechanismresponsibleforthisphenomenon,especiallyatthemolecularlevel,remainsunclearalthoughsomeprogresshasbeenachieved.Inthisstudy,weexaminedmRNAlevelsoftheTOR(targetofrapamycin)andDnmt3(DNAmethyltransferase3)genes,closelyrelatedtocastedifferentiationinhoneybees.WealsoinvestigatedmRNAexpressionoftheS6K(similartoRPS6-p70-proteinkinase)genelinkedcloselytoorganismalgrowthanddevelopmentinqueenandworkerlarvae(1-dayand3-dayold).Last,weinvestigatedthemethylationstatusofthesethreegenesincorrespondingcastes.WefoundnodifferenceinmRNAexpressionforthethreegenesbetween1stinstarqueenandworkerlarvae;however,3rdinstarqueenlarvaehadahigherlevelofTORmRNAthanworkerlarvae.Methylationlevelsofallthreegeneswerelowerinqueenlarvaethanworkerlarvaebutthedifferenceswerenotstatisticallysignificant.Thesefindingsprovidebasicdataforbroadeningourunderstandingofcastedifferentiationinfemalehoneybees.