Hemangioblast Commitment in the Avian Allantois: Cellular and Molecular Aspects

Developmental Biology

F. Dieterlen-Lièvre¹  T. Jaffredo¹  A. Caprioli¹  C. Drevon¹  K. Minko¹  A. Eichmann¹ 

[1] Institut d'Embryologie Cellulaire et Moléculaire du CNRS et du Collège de France, 49 bis av. de la Belle Gabrielle, 94736, Nogent s/Marne Cedex, France

关键词: hemangioblasts;    hemopoiesis;    allantois;    avian embryo;    GATA factors;    VEGF-R2;    SCL/tal-1;   

DOI  :  10.1006/dbio.2001.0362

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Werecentlyidentifiedtheallantoisasasiteproducinghemopoieticandendothelialcellscapableofcolonizingthebonemarrowofanengraftedhost.Here,wereportadetailedinvestigationofsomeearlycytologicalandmolecularprocessesoccurringintheallantoicbud,whichareprobablyinvolvedintheproductionofangioblastsandhemopoieticcells.Weshowthattheallantoisundergoesaprogramcharacterizedbytheprominentexpressionofseveral“hemangioblastic”genesinthemesodermaccompaniedbyothergenepatternsintheassociatedendoderm.VEGF-R2,atleastfromstageHH17onward,isexpressedandisshortlyfollowedbytranscriptionfactorsGATA-2,SCL/tal-1,andGATA-1.Bloodisland-likestructuresdifferentiatethatcontainbothCD45+cellsandcellsaccumulatinghemoglobin;thesestructureslookexactlylikebloodislandsintheyolksac.Thishemopoieticprocesstakesplacebeforetheestablishmentofavascularnetworkconnectingtheallantoistotheembryo.Asfarastheendodermisconcerned,GATA-3mRNAisfoundintheregionwhereallantoiswilldifferentiatebeforetheposteriorinstestinalportalbecomesanatomicallydistinct.Shortlybeforethebudgrowsout,GATA-2wasexpressedintheendodermand,atthesametime,thehemangioblasticprogrambecameinitiatedinthemesoderm.GATA-3isdetectedatleastuntilE8andGATA-2untilE3thelateststageexaminedforthisfactor.Usinginvitrocultures,weshowthatallantoicbuds,dissectedoutbeforetheestablishmentofcirculationbetweenthebudandtherestoftheembryo,producederythrocytesofthedefinitivelineage.Moreover,usingheterospecificgraftsbetweenchickandquailembryos,wedemonstratethattheallantoicvascularnetworkdevelopsfromintrinsicprogenitors.Takentogether,theseresultsextendourearlierfindingsaboutthecommitmentofmesodermtotheendothelialandhemopoieticlineagesintheallantois.ThedetectionofaprominentGATA-3expressionrestrictedtotheendodermofthepreallantoicregionandallantoicbud,followedbythatofGATA-2,isaninterestingandnovelinformation,inthecontextoforganformationandendodermspecificationintheemergenceofhemopoieticcells.

【 授权许可】

Unknown