Msx 2I sa Represso ro fChondrogeni cDifferentiatio nin Migrator yCrania lNeura lCres tCells

Durin gearl ymous eembryo- genesis ,crania lneura lcres tcell s(CNCC )emi- grat efro mth eposterio rmidbrai nan drhom- bomere s 1an d2 o fth eanterio rhindbrai ninto th efirs tbranchia larch-derive dmaxillar yand mandibula rprocesse san dther eprovid ecel llin- eage sfo rsevera lphenotypes ,includin gcarti- lage ,bone ,an dtooth .Here ,w erepor ttha tSox9 an dMsx 2wer ecoexpresse di na subpopulatio nof CNC Cdurin gthei rmigration .Becaus eSox 9i sa transactivato ro fchondrogenesis ,an dMs xgenes ca nac ta stranscriptiona lrepressors ,w ehypoth- esize dtha tSox 9expressio nindicate sth edeter- minatio no fCNCC-derive dchondrogeni ccel llin- eag ean dtha tMsx 2represse schondrogenic differentiatio nunti lCNC Cmigratio ni scom- plete dwithi nth emandibula rprocesses .T otest whethe rMsx 2represse schondrogenesis ,w ede- signe dexperiment st oinhibi tMsx 2functio nin migrator yCNC Ci nprimar yculture sthroug hthe expressio no floss-of-functio nMsx 2mutants .We showe dtha tinfectio no fmigrator yCNC Cwith adenoviru sMsx 2mutant saccelerate dth erate an dexten to fchondrogenesis ,a sindicate db ythe expressio nleve lo ftyp eI Icollage nan daggrecan, an dth eamoun to falcia nblu estaining .Adenovi- ru sinfection sdi dno tapparentl yinterfer ewith CNC Cproliferatio no rmigration .Thes efindings sugges ttha ta nimportan tearl yeven ti ncranio- facia lmorphogenesi si sa transien texpression o fbot hSox 9an dMsx 2durin gemigratio ninto th eformin gmandibula rprocesse sfollowe dby restricte dexpressio no fSox 9withi nCNCC- derive dchondroprogenito rcells .W econclude tha tMsx 2serve sa sa represso ro fchondro- geni cdifferentiatio ndurin gCNC Cmigration.