Bioengineering of Humanized Bone Marrow Microenvironments in Mouse and Their Visualization by Live Imaging

Human hematopoietic stem cells (HSCs) reside in the bone marrow (BM) niche, an intricate, multifactorial network of components producing cytokines, growth ...

The Francis Crick Institute

Cranial neural crest cells generate the distinctive bone and connective tissues in the vertebrate head. Classical models of craniofacial development argue that the neural crest is prepatterned or preprogrammed to make specific head structures before its migration from the neural tube. In contrast, recent studies in several vertebrates have provided evidence for plasticity in patterning neural crest populations. Using tissue transposition and molecular analyses in avian embryos, we reconcile these findings by demonstrating that classical manipulation experiments, which form the basis of the prepatterning model, involved transplantation of a local signaling center, the isthmic organizer. FGF8 signaling from the isthmus alters Hoxa2 expression and consequently branchial arch patterning, demonstrating that neural crest cells are patterned by environmental signals.

Role of the isthmus and FGFs in resolving the paradox of neural crest plasticity and prepatterning.

Pattern formation in the hindbrain is governed by a segmentation process that provides the basis for the organisation of cranial motor nerves. A cascade of transcriptional activators, including the bZIP transcription factor encoded by the kreisler gene controls this segmentation process. In kreisler mutants, r5 fails to form and this correlates with abnormalities in the neuroanatomical organisation of the hindbrain. Studies of Hox gene regulation suggest that kreisler may regulate the identity as well as the formation of r5, but such a role cannot be detected in kreisler mutants since r5 is absent. To gain further insights into the function of kreisler we have generated transgenic mice in which kreisler is ectopically expressed in r3 and for an extended period in r5. In these transgenic mice, the Fgf3, Krox20, Hoxa3 and Hoxb3 genes have ectopic or prolonged expression domains in r3, indicating that it acquires molecular characteristics of r5. Prolonged kreisler expression subsequently causes morphological alterations of r3/r5 that are due to an inhibition of neuronal differentiation and migration from the ventricular zone to form the mantle layer. We find that these alterations in r5 correlate with an arrest of facial branchiomotor neurone migration from r4 into the caudal hindbrain, which is possibly due to the deficiency in the mantle layer through which they normally migrate. We propose that the requirement for the downregulation of segmental kreisler expression prior to neuronal differentiation reflects the stage-specific roles of this gene and its targets.

Requirement for downregulation of kreisler during late patterning of the hindbrain.

Chromosomal translocation t(9;11)(p22;q23) in acute myeloid leukemia fuses the MLL and AF9 genes. We have inactivated the murine homologue of AF9 to elucidate its normal role. No effect on hematopoiesis was observed in mice with a null mutation of Af9. However, an Af9 null mutation caused perinatal lethality, and homozygous mice exhibited anomalies of the axial skeleton. Both the cervical and thoracic regions were affected by anterior homeotic transformation. Strikingly, mice lacking functional Af9 exhibited a grossly deformed atlas and an extra cervical vertebra. To determine the molecular mediators of this phenotype, analysis of Hox gene expression by in situ hybridization showed that Af9 null embryos have posterior changes in Hoxd4 gene expression. We conclude that the Af9 gene is required for normal embryogenesis in mice by controlling pattern formation, apparently via control of Hox gene regulation. This is analogous to the role of Mll, the murine homolog of human MLL, to which the Af9 gene fuses in acute myeloid leukemias.

Mouse Af9 is a controller of embryo patterning, like Mll, whose human homologue fuses with Af9 after chromosomal translocation in leukemia.

&#x4FA7;&#x6291;&#x5236;&#xFF0C;&#x4ECB;&#x5BFC;&#x7684; Notch &#x4FE1;&#x53F7;&#xFF0C;&#x5BFC;&#x81F4;&#x83B7;&#x51C6;&#x6210;&#x4E3A;&#x795E;&#x7ECF;&#x5143; proneural &#x57FA;&#x56E0;&#x8868;&#x8FBE;&#x5F0F;&#x6240;&#x5B9A;&#x4E49;&#x7684;&#x57DF;&#x5185;&#x7684;&#x5355;&#x5143;&#x683C;&#x7684;&#x9009;&#x5B9A;&#x3002;&#x6591;&#x9A6C;&#x9C7C; mib &#x7A81;&#x53D8;&#x4F53;&#x80DA;&#x80CE;&#x51CF;&#x5C11;&#x4FA7;&#x6291;&#x5236;&#x5141;&#x8BB8;&#x592A;&#x591A;&#x7684;&#x795E;&#x7ECF;&#x7956;&#x7EC6;&#x80DE;&#x5206;&#x5316;&#x4E3A;&#x795E;&#x7ECF;&#x5143;&#x3002;Mib &#x7684;&#x5B9A;&#x4F4D;&#x514B;&#x9686;&#x663E;&#x793A;&#x5B83;&#x662F;&#x5C06;&#x7F16;&#x7801;&#x73AF;&#x6CDB;&#x7D20;&#x8FDE;&#x63A5;&#x9176;&#x7684;&#x5207;&#x53E3;&#x9014;&#x5F84;&#x4E2D;&#x7684;&#x57FA;&#x56E0;&#x3002;Mib &#x4EA4;&#x4E92;&#x4E0E;&#x80DE;&#x5185;&#x57DF;&#x7684;&#x4E09;&#x89D2;&#x6D32;&#xFF0C;&#x4EE5;&#x4FC3;&#x8FDB;&#x5176;&#x6CDB;&#x7D20;&#x5316;&#x548C;&#x56FD;&#x9645;&#x5316;&#x3002;&#x7EC6;&#x80DE;&#x79FB;&#x690D;&#x7814;&#x7A76;&#x8868;&#x660E; mib &#x529F;&#x80FD;&#x81F3;&#x5173;&#x91CD;&#x8981;&#x7684;&#x4FE1;&#x4EE4;&#x5355;&#x5143;&#x683C;&#x4E2D;&#x7684;&#x6709;&#x6548;&#x6FC0;&#x6D3B;&#x7684;&#x69FD;&#x53E3;&#x4E2D;&#x76F8;&#x90BB;&#x5355;&#x5143;&#x683C;&#x3002;&#x8FD9;&#x4E9B;&#x610F;&#x89C1;&#x7684;&#x69FD;&#x53E3;&#x6FC0;&#x6D3B;&#x4E09;&#x89D2;&#x6D32;&#x69FD;&#x53E3;&#x7684;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x8DDF;&#x4E09;&#x89D2;&#x6D32;&#x7684;&#x5185;&#x541E;&#x4F5C;&#x7528;&#x548C; transendocytosis &#x7684;&#x69FD;&#x53E3;&#x80DE;&#x7531;&#x4FE1;&#x4EE4;&#x5355;&#x5143;&#x683C;&#x652F;&#x6301;&#x6A21;&#x578B;&#x3002;&#x8FD9;&#x65B9;&#x4FBF;&#x4E86;&#x5176;&#x4F59;&#x7684;&#x69FD;&#x53E3;&#x53D7;&#x4F53; intramembranous &#x5288;&#x88C2;&#x3001; &#x91CA;&#x653E;&#x7684;&#x51F9;&#x69FD;&#x5185;&#x6E38;&#x79BB;&#x7247;&#x6BB5;&#x548C;&#x5728;&#x76F8;&#x90BB;&#x5355;&#x5143;&#x683C;&#x7684;&#x9776;&#x57FA;&#x56E0;&#x7684;&#x6FC0;&#x6D3B;&#x3002;

&#x8003;&#x8651;&#x5230;&#x70B8;&#x5F39;&#x662F;&#x6CDB;&#x7D20;&#x8FDE;&#x63A5;&#x9176;&#x6240;&#x5FC5;&#x9700;&#x7684;&#x9AD8;&#x6548;&#x6D3B;&#x5316; Notch &#x7684;&#x4E09;&#x89D2;&#x6D32;&#x3002;

Lateral inhibition, mediated by Notch signaling, leads to the selection of cells that are permitted to become neurons within domains defined by proneural gene expression. Reduced lateral inhibition in zebrafish mib mutant embryos permits too many neural progenitors to differentiate as neurons. Positional cloning of mib revealed that it is a gene in the Notch pathway that encodes a RING ubiquitin ligase. Mib interacts with the intracellular domain of Delta to promote its ubiquitylation and internalization. Cell transplantation studies suggest that mib function is essential in the signaling cell for efficient activation of Notch in neighboring cells. These observations support a model for Notch activation where the Delta-Notch interaction is followed by endocytosis of Delta and transendocytosis of the Notch extracellular domain by the signaling cell. This facilitates intramembranous cleavage of the remaining Notch receptor, release of the Notch intracellular fragment, and activation of target genes in neighboring cells.

Mind bomb is a ubiquitin ligase that is essential for efficient activation of Notch signaling by Delta.

L&#x26;#39;inhibition lat&#xE9;rale, m&#xE9;di&#xE9;e par la signalisation Notch, conduit &#xE0; la s&#xE9;lection des cellules qui sont autoris&#xE9;s &#xE0; devenir des neurones au sein des domaines d&#xE9;finis par l&#x26;#39;expression des g&#xE8;nes proneural. R&#xE9;duit l&#x26;#39;inhibition lat&#xE9;rale dans embryons de poisson z&#xE8;bre mutant mib permet trop de prog&#xE9;niteurs neuronaux de diff&#xE9;rencier les neurones. Le clonage positionnel de mib r&#xE9;v&#xE9;l&#xE9; qu&#x26;#39;il s&#x26;#39;agit d&#x26;#39;un g&#xE8;ne dans la voie Notch qui code pour une ligase ubiquitine RING. Mib interagit avec le domaine intracellulaire de Delta pour promouvoir son ubiquitylation et de l&#x26;#39;internalisation. &#xC9;tudes de transplantation de cellules sugg&#xE8;rent que la fonction mib est essentiel dans la signalisation cellulaire pour l&#x26;#39;activation de Notch efficace dans les cellules voisines. Ces observations corroborent un mod&#xE8;le pour l&#x26;#39;activation de Notch, o&#xF9; l&#x26;#39;interaction Delta-Notch est suivie par endocytose de Delta et transendocytosis du domaine extracellulaire de Notch par la signalisation cellulaire. Cela facilite le clivage intramembranaire du r&#xE9;cepteur Notch restants, la lib&#xE9;ration du fragment Notch intracellulaire et l&#x26;#39;activation de g&#xE8;nes cibles dans les cellules voisines.

Mind Bomb est un ubiquitine ligase qui est essentielle pour l&#x26;#39;activation efficace de la signalisation Notch par Delta

Mind Bomb ist eine Ubiquitin-Ligase, die f&#xFC;r eine effiziente Aktivierung von Notch durch Delta ist.

Inibizione laterale, mediata dalla tacca di segnalazione, conduce alla selezione delle cellule che hanno il permesso di diventare neuroni all&#39;interno di domini definiti dall&#39;espressione del gene proneural. Ridotta inibizione laterale nell&#39;embrione mutante di zebrafish mib permette troppi progenitori neurali per differenziare come i neuroni. Clonazione posizionale di mib ha rivelato che si tratta di un gene nella via della tacca che codifica una ligasi di ubiquitin di anello. MIB interagisce con il dominio intracellulare di Delta per promuovere la sua ubiquitylation e interiorizzazione. Cella trapianto studi suggeriscono che mib funzione &egrave; essenziale nella cella di segnalazione per l&#39;efficace attivazione del tacca in celle vicine. Queste osservazioni supportano un modello per l&#39;attivazione di tacca dove l&#39;interazione Delta-Notch &egrave; seguita da endocitosi di Delta e transendocytosis del dominio extracellulare tacca dalla cellula di segnalazione. Questo facilita intramembranosa clivaggio del recettore Notch rimanente, rilascio del frammento intracellulare di Notch e l&#39;attivazione dei geni bersaglio in celle vicine.

Mente bomba &egrave; un&#39;ubiquitina ligasi che &egrave; essenziale per l&#39;efficiente attivazione della tacca di segnalazione di Delta.

Notch&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x306B;&#x3088;&#x3063;&#x3066;&#x5A92;&#x4ECB;&#x3055;&#x308C;&#x308B;&#x5074;&#x65B9;&#x6291;&#x5236;&#x306F;&#x3001;&#x30D7;&#x30ED;&#x30CB;&#x30E5;&#x30FC;&#x30E9;&#x30EB;&#x907A;&#x4F1D;&#x5B50;&#x306E;&#x767A;&#x73FE;&#x306B;&#x3088;&#x3063;&#x3066;&#x5B9A;&#x7FA9;&#x3055;&#x308C;&#x305F;&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x5185;&#x306E;&#x30CB;&#x30E5;&#x30FC;&#x30ED;&#x30F3;&#x306B;&#x306A;&#x308B;&#x3053;&#x3068;&#x3092;&#x8A31;&#x53EF;&#x3055;&#x308C;&#x3066;&#x3044;&#x308B;&#x7D30;&#x80DE;&#x306E;&#x9078;&#x629E;&#x306B;&#x3064;&#x306A;&#x304C;&#x308B;&#x3002;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x306E;mib&#x5909;&#x7570;&#x4F53;&#x80DA;&#x3067;&#x306F;&#x6E1B;&#x5C11;&#x3057;&#x5074;&#x65B9;&#x6291;&#x5236;&#x306F;&#x3001;&#x30CB;&#x30E5;&#x30FC;&#x30ED;&#x30F3;&#x3068;&#x533A;&#x5225;&#x3059;&#x308B;&#x305F;&#x3081;&#x306B;&#x3042;&#x307E;&#x308A;&#x306B;&#x3082;&#x591A;&#x304F;&#x306E;&#x795E;&#x7D4C;&#x524D;&#x99C6;&#x7D30;&#x80DE;&#x3092;&#x8A31;&#x53EF;&#x3057;&#x307E;&#x3059;&#x3002; MIB&#x306E;&#x30DD;&#x30B8;&#x30B7;&#x30E7;&#x30CA;&#x30EB;&#x30AF;&#x30ED;&#x30FC;&#x30CB;&#x30F3;&#x30B0;&#x306F;&#x3001;RING&#x30E6;&#x30D3;&#x30AD;&#x30C1;&#x30F3;&#x30EA;&#x30AC;&#x30FC;&#x30BC;&#x3092;&#x30B3;&#x30FC;&#x30C9;&#x3057;&#x3066;&#x3044;&#x308B;Notch&#x7D4C;&#x8DEF;&#x306E;&#x907A;&#x4F1D;&#x5B50;&#x3067;&#x3042;&#x308B;&#x3053;&#x3068;&#x3092;&#x660E;&#x3089;&#x304B;&#x306B;&#x3057;&#x305F;&#x3002; MIB&#x306F;&#x3001;&#x305D;&#x306E;&#x30E6;&#x30D3;&#x30AD;&#x30C1;&#x30F3;&#x5316;&#x3068;&#x5185;&#x5728;&#x5316;&#x3092;&#x4FC3;&#x9032;&#x3059;&#x308B;&#x305F;&#x3081;&#x306B;&#x30C7;&#x30EB;&#x30BF;&#x306E;&#x7D30;&#x80DE;&#x5185;&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x3068;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x3059;&#x308B;&#x3002;&#x7D30;&#x80DE;&#x79FB;&#x690D;&#x306E;&#x7814;&#x7A76;&#x306F;&#x3001;MIB&#x6A5F;&#x80FD;&#x306F;&#x3001;&#x96A3;&#x63A5;&#x30BB;&#x30EB;&#x306B;&#x304A;&#x3051;&#x308B;Notch&#x306E;&#x52B9;&#x7387;&#x7684;&#x306A;&#x6D3B;&#x6027;&#x5316;&#x306E;&#x305F;&#x3081;&#x306E;&#x7D30;&#x80DE;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x306B;&#x4E0D;&#x53EF;&#x6B20;&#x3067;&#x3042;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x5506;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;&#x3053;&#x308C;&#x3089;&#x306E;&#x89B3;&#x200B;&#x200B;&#x5BDF;&#x306F;&#x3001;&#x30C7;&#x30EB;&#x30BF; - &#x30CE;&#x30C3;&#x30C1;&#x306E;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x304C;&#x7D30;&#x80DE;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x306B;&#x3088;&#x308B;Notch&#x306E;&#x7D30;&#x80DE;&#x5916;&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x306E;&#x30C7;&#x30EB;&#x30BF;&#x3068;transendocytosis&#x306E;&#x30A8;&#x30F3;&#x30C9;&#x30B5;&#x30A4;&#x30C8;&#x30FC;&#x30B7;&#x30B9;&#x306B;&#x7D9A;&#x3044;&#x3066;Notch&#x6D3B;&#x6027;&#x5316;&#x306E;&#x30E2;&#x30C7;&#x30EB;&#x3092;&#x30B5;&#x30DD;&#x30FC;&#x30C8;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x3053;&#x308C;&#x306F;&#x3001;&#x6B8B;&#x308A;&#x306E;Notch&#x53D7;&#x5BB9;&#x4F53;&#x3001;Notch&#x7D30;&#x80DE;&#x5185;&#x306E;&#x30D5;&#x30E9;&#x30B0;&#x30E1;&#x30F3;&#x30C8;&#x306E;&#x30EA;&#x30EA;&#x30FC;&#x30B9;&#x3001;&#x304A;&#x3088;&#x3073;&#x96A3;&#x63A5;&#x30BB;&#x30EB;&#x5185;&#x306E;&#x6A19;&#x7684;&#x907A;&#x4F1D;&#x5B50;&#x306E;&#x6D3B;&#x6027;&#x5316;&#x306E;&#x819C;&#x5185;&#x5207;&#x65AD;&#x3092;&#x5BB9;&#x6613;&#x306B;&#x3057;&#x307E;&#x3059;&#x3002;

&#x30DE;&#x30A4;&#x30F3;&#x30C9;&#xB7;&#x30DC;&#x30E0;&#x306F;&#x3001;&#x30C7;&#x30EB;&#x30BF;&#x306B;&#x3088;&#x308B;Notch&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x306E;&#x52B9;&#x7387;&#x7684;&#x306A;&#x6D3B;&#x6027;&#x5316;&#x306B;&#x5FC5;&#x9808;&#x3067;&#x3042;&#x308B;&#x30E6;&#x30D3;&#x30AD;&#x30C1;&#x30F3;&#x30EA;&#x30AC;&#x30FC;&#x30BC;&#x3067;&#x3042;&#x308B;

&#xB178;&#xCE58; &#xC2E0;&#xD638;&#xC5D0; &#xC758;&#xD574; &#xC911;&#xC7AC; &#xCE21;&#xBA74; &#xC800;&#xD574;&#xB294; proneural &#xC720;&#xC804;&#xC790; &#xBC1C;&#xD604;&#xC5D0; &#xC758;&#xD574; &#xC815;&#xC758; &#xB41C; &#xB3C4;&#xBA54;&#xC778; &#xB0B4;&#xC5D0;&#xC11C; &#xC2E0;&#xACBD; &#xC138;&#xD3EC;&#xAC00; &#xB420; &#xC218; &#xC788;&#xB294; &#xC140;&#xC758; &#xC120;&#xD0DD;&#xC73C;&#xB85C; &#xC774;&#xC5B4;&#xC9D1;&#xB2C8;&#xB2E4;. Zebrafish mib &#xB3CC;&#xC5F0;&#xBCC0;&#xC774; &#xCCB4; &#xBC30;&#xC544;&#xC5D0; &#xAC10;&#xC18C; &#xCE21;&#xBA74; &#xC5B5;&#xC81C; &#xC2E0;&#xACBD;&#xC73C;&#xB85C; &#xCC28;&#xBCC4;&#xD654; &#xD558;&#xB294; &#xB370; &#xB108;&#xBB34; &#xB9CE;&#xC740; &#xC2E0;&#xACBD; progenitors &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. Mib&#xC758; &#xC704;&#xCE58; &#xBCF5;&#xC81C; &#xB9C1; &#xC720;&#xBE44;&#xD034;&#xD2F4; &#xB9AC;&#xAC00; &#xC778;&#xCF54;&#xB529;&#xD569;&#xB2C8;&#xB2E4; &#xB178;&#xCE58; &#xD1B5;&#xB85C;&#xC5D0;&#xC11C; &#xC720;&#xC804;&#xC790; &#xC784;&#xC744; &#xBC1D;&#xD614;&#xB2E4;. Mib&#xC758; ubiquitylation&#xC640; &#xAD6D;&#xC81C;&#xD654;&#xB97C; &#xCD09;&#xC9C4; &#xD558;&#xB294; &#xB378;&#xD0C0;&#xC758; &#xC138;&#xD3EC;&#xB0B4; &#xB3C4;&#xBA54;&#xC778; &#xC0C1;&#xD638; &#xC791;&#xC6A9; &#xD569;&#xB2C8;&#xB2E4;. &#xC138;&#xD3EC; &#xC774;&#xC2DD; &#xC5F0;&#xAD6C; mib &#xD568;&#xC218;&#xB294; &#xD544;&#xC218;&#xC801;&#xC778; &#xC2E0;&#xD638; &#xC140;&#xC5D0; &#xB178;&#xCE58;&#xC758; &#xD6A8;&#xC728;&#xC801;&#xC778; &#xD65C;&#xC131;&#xD654;&#xB97C; &#xC704;&#xD55C; &#xC778;&#xC811; &#xD55C; &#xC140;&#xC5D0; &#xAC83;&#xC774; &#xC88B;&#xC2B5;&#xB2C8;&#xB2E4;. &#xC774;&#xB7EC;&#xD55C; &#xAD00;&#xCE21; &#xB378;&#xD0C0; &#xB178;&#xCE58; &#xC0C1;&#xD638; &#xC791;&#xC6A9; &#xB378;&#xD0C0; endocytosis &#xBC0F; &#xC2E0;&#xD638; &#xC140;&#xBCC4; &#xB178;&#xCE58; &#xC138;&#xD3EC; &#xC678; &#xB3C4;&#xBA54;&#xC778;&#xC758; transendocytosis&#xC5D0; &#xC758;&#xD574; &#xB2E4;&#xC74C;&#xC740; &#xB178;&#xCE58; &#xD65C;&#xC131;&#xD654;&#xB97C; &#xC704;&#xD55C; &#xBAA8;&#xB378;&#xC744; &#xC9C0;&#xC6D0; &#xD569;&#xB2C8;&#xB2E4;. &#xC774; &#xB098;&#xBA38;&#xC9C0; &#xB178;&#xCE58; &#xC218;&#xC6A9; &#xCCB4;&#xC758; intramembranous &#xBD84;&#xC5F4;, &#xC138;&#xD3EC;&#xB0B4; &#xB178;&#xCE58; &#xC870;&#xAC01;&#xC758; &#xB9B4;&#xB9AC;&#xC2A4; &#xC778;&#xC811; &#xD55C; &#xC140;&#xC5D0; &#xB300;&#xC0C1; &#xC720;&#xC804;&#xC790;&#xC758; &#xD65C;&#xC131;&#xD654;&#xB97C; &#xCD09;&#xC9C4; &#xD55C;&#xB2E4;.

&#xB9C8;&#xC74C; &#xD3ED;&#xD0C4;&#xC740; &#xB378;&#xD0C0;&#xC5D0; &#xC758;&#xD574; &#xC2E0;&#xD638; &#xB178;&#xCE58;&#xC758; &#xD6A8;&#xC728;&#xC801;&#xC778; &#xD65C;&#xC131;&#xD654;&#xB97C; &#xC704;&#xD574; &#xD544;&#xC218;&#xC801;&#xC778; &#xC720;&#xBE44;&#xD034;&#xD2F4; &#xB9AC;&#xAC00;.

La inhibici&#xF3;n lateral, mediada por la se&#xF1;alizaci&#xF3;n de Notch, lleva a la selecci&#xF3;n de las c&#xE9;lulas que est&#xE1;n permitidos para convertirse en neuronas dentro de los dominios definidos por la expresi&#xF3;n de genes proneural. La inhibici&#xF3;n lateral reducida en el pez cebra mib embriones mutantes permite progenitores neurales demasiados para diferenciarse como neuronas. La clonaci&#xF3;n posicional de mib revel&#xF3; que es un gen en la v&#xED;a de Notch que codifica una ligasa ANILLO ubiquitina. Mib interact&#xFA;a con el dominio intracelular de Delta para promover su ubiquitinaci&#xF3;n y la internalizaci&#xF3;n. Estudios de trasplante de c&#xE9;lulas sugieren que la funci&#xF3;n MIB es esencial en la celda de se&#xF1;alizaci&#xF3;n para la activaci&#xF3;n eficaz de Notch en las c&#xE9;lulas vecinas. Estas observaciones apoyan un modelo para la activaci&#xF3;n de Notch, donde se sigue la interacci&#xF3;n Delta-Notch por endocitosis de Delta y transendocytosis del dominio extracelular de Notch por la se&#xF1;alizaci&#xF3;n celular. Esto facilita la divisi&#xF3;n intramembranosa del receptor Notch restante, la liberaci&#xF3;n del fragmento intracelular Notch, y la activaci&#xF3;n de los genes diana en las c&#xE9;lulas vecinas.

Mind Bomb es una ubiquitina ligasa que es esencial para la activaci&#xF3;n eficaz de se&#xF1;alizaci&#xF3;n de Notch por Delta

&#x4E09;&#x89D2;&#x6D32;&#x86CB;&#x767D;&#x8D28;&#x7ED3;&#x5408;&#x53CD;&#x5E94;&#xFF0C;&#x53D6;&#x51B3;&#x4E8E;&#x5176;&#x80DE;&#x5916;&#x7684;&#x57DF; &#xFF1B; &#x901A;&#x8FC7;&#x6FC0;&#x6D3B;&#x69FD;&#x53E3;&#x4F46;&#x7EC6;&#x80DE;&#x5185; &#xFF08;C &#x7EC8;&#x7AEF;&#xFF09; &#x57DF;&#x7684;&#x589E;&#x91CF;&#x90E8;&#x5206;&#x4E5F;&#x6709;&#x91CD;&#x8981;&#x7684;&#x529F;&#x80FD;&#x3002;&#x6240;&#x6709;&#x5404;&#x7C7B;&#x810A;&#x690E;&#x52A8;&#x7269;&#x62E5;&#x6709;&#x4E0E;&#x5B88;&#x6052; ATEV * &#x6BCD;&#x9898;&#x5728;&#x5176; C &#x603B;&#x7AD9;&#x4E09;&#x89D2;&#x6D32;&#x86CB;&#x767D;&#x8D28;&#x7684;&#x4E00;&#x4E2A;&#x5B50;&#x96C6;&#x3002;&#x8FD9;&#x4E9B; ATEV &#x4E09;&#x89D2;&#x6D32;&#x5305;&#x62EC; Delta1 Delta4 &#x5728;&#x54FA;&#x4E73;&#x52A8;&#x7269;&#x548C; DeltaD &#x548C; DeltaC &#x5728;&#x6591;&#x9A6C;&#x9C7C;&#x4E2D;&#x3002;&#x6211;&#x4EEC;&#x663E;&#x793A;&#x8FD9;&#x4E9B;&#x4E09;&#x89D2;&#x6D32;&#x5173;&#x8054;&#x7684;&#x819C;&#x76F8;&#x5173;&#x811A;&#x624B;&#x67B6;&#x86CB;&#x767D; MAGI1&#x3001; MAGI2 &#x548C; MAGI3&#xFF0C;&#x901A;&#x8FC7;&#x589E;&#x91CF;&#x90E8;&#x5206;&#x7684; C &#x603B;&#x7AD9;&#x548C; MAGIs &#x5177;&#x4F53; pdz &#xFF08;PDZ4&#xFF09; &#x4E4B;&#x95F4;&#x7684;&#x76F4;&#x63A5;&#x4E92;&#x52A8;&#x3002;&#x5728;&#x57F9;&#x517B;&#x7EC6;&#x80DE;&#x548C;&#x5B8C;&#x597D;&#x7684;&#x6591;&#x9A6C;&#x9C7C;&#x80DA;&#x80CE;&#x7EC6;&#x80DE;&#x4E9A;&#x7FA4;&#xFF0C;DeltaD &#x548C; MAGI1 &#x662F; co-localized &#x5728;&#x7EC6;&#x80DE;&#x8D28;&#x819C;&#x3002;&#x4E92;&#x52A8;&#x548C;&#x4EA4;&#x611F;&#x795E;&#x7ECF;&#x53EF;&#x4EE5;&#x963B;&#x6B62; mRNA &#x526A;&#x63A5;&#x53CD;&#x5E94;&#xFF0C;&#x4F7F;&#x5176;&#x7EC8;&#x7AEF;&#x7F2C;&#x6C28;&#x9178;&#xFF0C;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x6240;&#x4F9D;&#x8D56;&#x7684; DeltaD &#x7684; morpholino &#x6CE8;&#x5C04;&#x5E9F;&#x9664;&#x3002;&#x4EE5;&#x8FD9;&#x79CD;&#x65B9;&#x5F0F;&#x5BF9;&#x5F85;&#x80DA;&#x80CE;&#x663E;&#x793A;&#x6B63;&#x5E38;&#x4E00;&#x4E9B;&#x5DF2;&#x77E5;&#x529F;&#x80FD;&#x7684; DeltaD &#x4E3A;&#x69FD;&#x53E3;&#x914D;&#x4F53;&#xFF0C;&#x5305;&#x62EC;&#x63A7;&#x5236;&#x4F53;&#x8282;&#x5206;&#x5272;&#x3001; &#x795E;&#x7ECF;&#x53D1;&#x751F;&#x4E0E; hypochord &#x5F62;&#x6210;&#x3002;&#x4E0D;&#x8FC7;&#xFF0C;&#x4ED6;&#x4EEC;&#x505A;&#xFF0C;&#x663E;&#x793A; Rohon &#x80E1;&#x5B50;&#x795E;&#x7ECF;&#x5143;&#x5F02;&#x5E38;&#x5206;&#x5E03;&#x80CC;&#x795E;&#x7ECF;&#x7BA1;&#xFF0C;&#x6697;&#x793A;&#x4E09;&#x89D2;&#x6D32;&#x9EA6;&#x742A;&#x7684;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x53EF;&#x80FD;&#x5728;&#x795E;&#x7ECF;&#x5143;&#x8FC1;&#x79FB;&#x7684;&#x63A7;&#x5236;&#x65B9;&#x9762;&#x53D1;&#x6325;&#x7684;&#x67D0;&#x4E9B;&#x90E8;&#x5206;&#x3002;

&#x4E09;&#x89D2;&#x6D32;&#x86CB;&#x767D;&#x53CA;&#x8D24;&#x58EB;&#x86CB;&#x767D;&#xFF1A; &#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x7684;&#x7ED3;&#x679C;&#xFF0C;&#x69FD;&#x53E3;&#x914D;&#x4F53;&#x4E0E;&#x7EC6;&#x80DE;&#x5185;&#x7684;&#x811A;&#x624B;&#x67B6;&#x5206;&#x5B50;&#x548C;&#x6591;&#x9A6C;&#x9C7C;&#x53D1;&#x5C55;&#x53CA;&#x5176;&#x610F;&#x4E49;&#x3002;

Delta proteins activate Notch through a binding reaction that depends on their extracellular domains; but the intracellular (C-terminal) domains of the Deltas also have significant functions. All classes of vertebrates possess a subset of Delta proteins with a conserved ATEV* motif at their C termini. These ATEV Deltas include Delta1 and Delta4 in mammals and DeltaD and DeltaC in the zebrafish. We show that these Deltas associate with the membrane-associated scaffolding proteins MAGI1, MAGI2 and MAGI3, through a direct interaction between the C termini of the Deltas and a specific PDZ domain (PDZ4) of the MAGIs. In cultured cells and in subsets of cells in the intact zebrafish embryo, DeltaD and MAGI1 are co-localized at the plasma membrane. The interaction and the co-localization can be abolished by injection of a morpholino that blocks the mRNA splicing reaction that gives DeltaD its terminal valine, on which the interaction depends. Embryos treated in this way appear normal with respect to some known functions of DeltaD as a Notch ligand, including the control of somite segmentation, neurogenesis, and hypochord formation. They do, however, show an anomalous distribution of Rohon-Beard neurons in the dorsal neural tube, suggesting that the Delta-MAGI interaction may play some part in the control of neuron migration.

Delta proteins and MAGI proteins: an interaction of Notch ligands with intracellular scaffolding molecules and its significance for zebrafish development.

Delta prot&#xE9;ines activer Notch par une r&#xE9;action de liaison qui d&#xE9;pend de leurs domaines extracellulaires, mais les intracellulaires (C-terminal) de domaines des deltas &#xE9;galement des fonctions importantes. Toutes les classes de vert&#xE9;br&#xE9;s poss&#xE8;dent un sous-ensemble de prot&#xE9;ines Delta avec un motif ATEV * conserv&#xE9; &#xE0; leurs extr&#xE9;mit&#xE9;s C. Ces deltas ATEV comprennent Delta1 et Delta4 chez les mammif&#xE8;res et DeltaD et DeltaC chez le poisson z&#xE8;bre. Nous montrons que ces deltas associer &#xE0; des prot&#xE9;ines d&#x26;#39;&#xE9;chafaudage associ&#xE9;es &#xE0; la membrane MAGI1, MAGI2 et MAGI3, &#xE0; travers une interaction directe entre les terminus de C des deltas et un domaine sp&#xE9;cifique PDZ (PDZ4) de la Magis. Dans les cellules cultiv&#xE9;es et en sous-ensembles de cellules de l&#x26;#39;embryon de poisson z&#xE8;bre intacte, et DeltaD MAGI1 sont co-localis&#xE9;s &#xE0; la membrane plasmique. L&#x26;#39;interaction et la co-localisation peut &#xEA;tre abolie par l&#x26;#39;injection d&#x26;#39;un morpholino qui bloque la r&#xE9;action &#xE9;pissage de l&#x26;#39;ARNm qui donne son DeltaD valine terminal, sur lequel l&#x26;#39;interaction d&#xE9;pend. Les embryons trait&#xE9;s de cette fa&#xE7;on une apparence normale &#xE0; l&#x26;#39;&#xE9;gard de certaines fonctions connues de DeltaD comme un ligand de Notch, y compris le contr&#xF4;le de la segmentation des somites, la neurogen&#xE8;se et la formation hypochord. Ils ne montrent cependant une distribution anormale des Rohon-Barbe neurones dans le tube neural dorsal, ce qui sugg&#xE8;re que l&#x26;#39;interaction Delta-MAGI peut jouer un certain r&#xF4;le dans le contr&#xF4;le de la migration des neurones.

Prot&#xE9;ines et prot&#xE9;ines Delta MAGI: une interaction de ligands de Notch avec des mol&#xE9;cules intracellulaires d&#x26;#39;&#xE9;chafaudage et son importance pour le d&#xE9;veloppement poisson z&#xE8;bre

Delta-Proteine &#x200B;&#x200B;und Proteine &#x200B;&#x200B;MAGI: eine Interaktion von Notch-Liganden mit intrazellul&#xE4;ren Ger&#xFC;st Molek&#xFC;le und ihre Bedeutung f&#xFC;r die Zebrafisch-Entwicklung.

Le proteine Delta attivare Notch attraverso una reazione di binding che dipende dalla loro domini extracellulari; ma i domini intracellulari (C-terminale) del Delta hanno anche importanti funzioni. Tutte le classi di vertebrati possiedono un sottoinsieme delle proteine Delta con un motivo ATEV * conservata a loro termini C. Questi Delta ATEV includono Delta1 e &Delta;4 nei mammiferi e DeltaD e DeltaC in the zebrafish. Mostriamo che questi Delta si associa con le proteine di membrana associati ponteggi MAGI1, MAGI2 e MAGI3, attraverso un&#39;interazione diretta tra i termini C del Delta e uno specifico dominio PDZ (PDZ4) della MAGIs. In cellule in coltura e in sottoinsiemi di cellule nell&#39;embrione dello zebrafish intatto, DeltaD e MAGI1 sono co-localized alla membrana del plasma. L&#39;interazione e la collocazione pu&ograve; essere abolite da iniezione di un oligonucleotides che blocca il mRNA impionbatura reazione che d&agrave; DeltaD sua valina terminale, da cui dipende l&#39;interazione. Embrioni trattati in questo modo appaiono normali per quanto riguarda alcune funzioni di DeltaD conosciuti come un ligando Notch, compreso il controllo della formazione di segmentazione, neurogenesi e hypochord somite. , Tuttavia, mostrano una distribuzione anomala dei neuroni Rohon-barba in tubo neurale dorsale, suggerendo che l&#39;interazione Delta-MAGI pu&ograve; giocare qualche parte del controllo della migrazione del neurone.

Delta proteine e proteine MAGI: un&#39;interazione di ligandi tacca con molecole intracellulari ponteggi e la sua importanza per lo sviluppo dello zebrafish.

&#x30C7;&#x30EB;&#x30BF;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x306F;&#x3001;&#x305D;&#x308C;&#x3089;&#x306E;&#x7D30;&#x80DE;&#x5916;&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x306B;&#x4F9D;&#x5B58;&#x3057;&#x3066;&#x7D50;&#x5408;&#x53CD;&#x5FDC;&#x3092;&#x4ECB;&#x3057;&#x3066;Notch&#x3092;&#x6D3B;&#x6027;&#x5316;&#x3059;&#x308B;&#x3001;&#x3057;&#x304B;&#x3057;&#x30C7;&#x30EB;&#x30BF;&#x306E;&#x7D30;&#x80DE;&#xFF08;C&#x672B;&#x7AEF;&#xFF09;&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x306F;&#x3001;&#x91CD;&#x8981;&#x306A;&#x6A5F;&#x80FD;&#x3092;&#x6301;&#x3063;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x810A;&#x690E;&#x52D5;&#x7269;&#x306E;&#x3059;&#x3079;&#x3066;&#x306E;&#x30AF;&#x30E9;&#x30B9;&#x306F;&#x305D;&#x306E;C&#x672B;&#x7AEF;&#x306B;&#x4FDD;&#x5B58;&#x3055;&#x308C;ATEV *&#x306E;&#x30E2;&#x30C1;&#x30FC;&#x30D5;&#x306B;&#x3057;&#x305F;&#x30C7;&#x30EB;&#x30BF;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x306E;&#x30B5;&#x30D6;&#x30BB;&#x30C3;&#x30C8;&#x3092;&#x6301;&#x3063;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x3053;&#x308C;&#x3089;&#x306E;ATEV&#x30C7;&#x30EB;&#x30BF;&#x306F;Delta1&#x3068;Delta4&#x54FA;&#x4E73;&#x985E;&#x3068;DeltaD&#x3068;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x3067;DeltaC&#x304C;&#x542B;&#x307E;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x6211;&#x3005;&#x306F;&#x3001;&#x3053;&#x308C;&#x3089;&#x306E;&#x30C7;&#x30EB;&#x30BF;&#x306F;&#x3001;&#x30C7;&#x30EB;&#x30BF;&#x306E;C&#x672B;&#x7AEF;&#x3068;&#x30DE;&#x30B8;&#x30B9;&#x306E;&#x7279;&#x5B9A;&#x306E;PDZ&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#xFF08;PDZ4&#xFF09;&#x3068;&#x306E;&#x9593;&#x306E;&#x76F4;&#x63A5;&#x7684;&#x306A;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x3092;&#x901A;&#x3058;&#x3066;&#x3001;&#x819C;&#x95A2;&#x9023;&#x8DB3;&#x5834;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;MAGI1&#x3001;MAGI2&#x3068;MAGI3&#x306B;&#x95A2;&#x9023;&#x4ED8;&#x3051;&#x3089;&#x308C;&#x3066;&#x3044;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x57F9;&#x990A;&#x7D30;&#x80DE;&#x3067;&#x306F;&#x3001;&#x7121;&#x50B7;&#x306E;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x80DA;&#x306B;&#x304A;&#x3051;&#x308B;&#x7D30;&#x80DE;&#x306E;&#x30B5;&#x30D6;&#x30BB;&#x30C3;&#x30C8;&#x3067;&#x3001;DeltaD&#x3068;MAGI1&#x306F;&#x7D30;&#x80DE;&#x819C;&#x3067;&#x5171;&#x5C40;&#x5728;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x3068;&#x5171;&#x5C40;&#x5728;&#x306F;&#x3001;&#x305D;&#x306E;&#x30D6;&#x30ED;&#x30C3;&#x30AF;&#x306E;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x304C;&#x4F9D;&#x5B58;&#x3057;&#x3066;&#x3001;&#x305D;&#x306E;&#x672B;&#x7AEF;&#x30D0;&#x30EA;&#x30F3;&#x3092;DeltaD&#x4E0E;&#x3048;&#x308B;mRNA&#x30B9;&#x30D7;&#x30E9;&#x30A4;&#x30B7;&#x30F3;&#x30B0;&#x53CD;&#x5FDC;&#x3092;&#x30E2;&#x30EB;&#x30DB;&#x30EA;&#x30CE;&#x306E;&#x6CE8;&#x5165;&#x306B;&#x3088;&#x308A;&#x5EC3;&#x6B62;&#x3059;&#x308B;&#x3053;&#x3068;&#x304C;&#x3067;&#x304D;&#x307E;&#x3059;&#x3002;&#x3053;&#x306E;&#x3088;&#x3046;&#x306B;&#x51E6;&#x7406;&#x3055;&#x308C;&#x305F;&#x80DA;&#x306F;&#x4F53;&#x7BC0;&#x533A;&#x5206;&#x3001;&#x795E;&#x7D4C;&#x3001;&#x304A;&#x3088;&#x3073;hypochord&#x5F62;&#x6210;&#x306E;&#x5236;&#x5FA1;&#x3092;&#x542B;&#x3080;Notch&#x30EA;&#x30AC;&#x30F3;&#x30C9;&#x3068;&#x3057;&#x3066;DeltaD&#x306E;&#x3044;&#x304F;&#x3064;&#x304B;&#x306E;&#x65E2;&#x77E5;&#x306E;&#x6A5F;&#x80FD;&#x306B;&#x95A2;&#x3057;&#x3066;&#x306F;&#x6B63;&#x5E38;&#x306B;&#x8868;&#x793A;&#x3055;&#x308C;&#x307E;&#x3059;&#x3002;&#x3057;&#x304B;&#x3057;&#x3001;&#x5F7C;&#x3089;&#x306F;&#x30C7;&#x30EB;&#x30BF;&#xB7;MAGI&#x306E;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x304C;&#x795E;&#x7D4C;&#x7D30;&#x80DE;&#x904A;&#x8D70;&#x306E;&#x5236;&#x5FA1;&#x306B;&#x4F55;&#x3089;&#x304B;&#x306E;&#x5F79;&#x5272;&#x3092;&#x679C;&#x305F;&#x3059;&#x3053;&#x3068;&#x3092;&#x793A;&#x5506;&#x3057;&#x3001;&#x795E;&#x7D4C;&#x7BA1;&#x80CC;&#x5074;&#x306B;Rohon&#xB7;&#x30D3;&#x30A2;&#x30FC;&#x30C9;&#x30CB;&#x30E5;&#x30FC;&#x30ED;&#x30F3;&#x306E;&#x7570;&#x5E38;&#x306A;&#x5206;&#x5E03;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x306A;&#x3044;&#x3002;

&#x30C7;&#x30EB;&#x30BF;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x3068;MAGI&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#xFF1A;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x306E;&#x958B;&#x767A;&#x306E;&#x305F;&#x3081;&#x306E;&#x7D30;&#x80DE;&#x5185;&#x8DB3;&#x5834;&#x5206;&#x5B50;&#x3068;&#x305D;&#x306E;&#x610F;&#x7FA9;&#x3068;Notch&#x30EA;&#x30AC;&#x30F3;&#x30C9;&#x306E;&#x76F8;&#x4E92;&#x4F5C;&#x7528;

&#xB378;&#xD0C0; &#xB2E8;&#xBC31;&#xC9C8;&#xC758; &#xC138;&#xD3EC; &#xC678; &#xB3C4;&#xBA54;&#xC778;;&#xC5D0; &#xB530;&#xB77C; &#xBC14;&#xC778;&#xB529; &#xBC18;&#xC751;&#xC744; &#xD1B5;&#xD574; &#xB178;&#xCE58;&#xB97C; &#xD65C;&#xC131;&#xD654; &#xADF8;&#xB7EC;&#xB098; &#xB378;&#xD0C0;&#xC758; &#xC138;&#xD3EC;&#xB0B4; (&#xB2E8;&#xC790;) &#xB3C4;&#xBA54;&#xC778;&#xB3C4; &#xC0C1;&#xB2F9;&#xD55C; &#xAE30;&#xB2A5;&#xC744;&#xAC00;&#xC9C0;&#xACE0; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. &#xCC99;&#xCD94; &#xB3D9;&#xBB3C;&#xC758; &#xBAA8;&#xB4E0; &#xD074;&#xB798;&#xC2A4; &#xB4E4;&#xC740; C &#xD14C;&#xB974;&#xBBF8;&#xB2C8;&#xC5D0;&#xC11C; &#xBCF4;&#xC874;&#xB41C; ATEV * &#xBAA8;&#xD2F0;&#xBE0C;&#xC640; &#xB378;&#xD0C0; &#xB2E8;&#xBC31;&#xC9C8;&#xC758; &#xD558;&#xC704; &#xC9D1;&#xD569; &#xBCF4;&#xC720;. &#xC774;&#xB7EC;&#xD55C; ATEV &#xB378;&#xD0C0;&#xB294; zebrafish&#xC758; &#xD3EC;&#xC720;&#xB958;&#xC640; Deltad&#xC640; Deltac&#xC5D0; Delta1 &#xBC0F; delta4&#xB97C; &#xD3EC;&#xD568;&#xD569;&#xB2C8;&#xB2E4;. &#xC6B0;&#xB9AC;&#xB294; &#xC774;&#xB7EC;&#xD55C; &#xB378;&#xD0C0; &#xB378;&#xD0C0;&#xC758; C &#xD14C;&#xB974;&#xBBF8;&#xB2C8;&#xB294; Magis&#xC758; &#xD2B9;&#xC815; PDZ &#xB3C4;&#xBA54;&#xC778; (PDZ4) &#xC0AC;&#xC774; &#xC9C1;&#xC811;&#xC801;&#xC778; &#xC0C1;&#xD638; &#xC791;&#xC6A9;&#xC744; &#xD1B5;&#xD574; &#xBA64;&#xBE0C;&#xB808;&#xC778; &#xAD00;&#xB828; &#xB41C; &#xC2A4; &#xCE90; &#xD3F4;&#xB529; &#xB2E8;&#xBC31;&#xC9C8; MAGI1, MAGI2 &#xBC0F; MAGI3, &#xC5F0;&#xAD00; &#xBCF4;&#xC5EC;&#xC90D;&#xB2C8;&#xB2E4;. &#xBC30;&#xC591;&#xB41C; &#xC138;&#xD3EC;&#xC640; &#xADF8;&#xB300;&#xB85C; zebrafish &#xD0DC;&#xC544;&#xC5D0; &#xC788;&#xB294; &#xC140;&#xC758; &#xD558;&#xC704; &#xC9D1;&#xD569;&#xC5D0;&#xC11C; DeltaD &#xBC0F; magi1&#xB294; &#xC6D0;&#xD615;&#xC9C8; &#xB9C9;&#xC5D0; co-localized. &#xC0C1;&#xD638; &#xC791;&#xC6A9; &#xD558; &#xACE0; &#xC788;&#xB294; co-localization &#xC811;&#xD569; &#xC0C1;&#xD638; &#xC885;&#xC18D;&#xC758; &#xD130;&#xBBF8;&#xB110; valine Deltad&#xB97C; &#xC8FC;&#xB294; &#xBC18;&#xC751; Mrna&#xB97C; &#xCC28;&#xB2E8; &#xD558;&#xB294; morpholino&#xC758; &#xC8FC;&#xC785;&#xC5D0; &#xC758;&#xD574; &#xD3D0;&#xC9C0; &#xB420; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. &#xBC30;&#xC544;&#xAC00; &#xBC29;&#xC2DD;&#xC5D0;&#xC11C;&#xC73C;&#xB85C; &#xCC98;&#xB9AC; somite &#xC138;&#xBD84;&#xD654;, &#xC131;&#xCCB4;, &#xBC0F; hypochord &#xD615;&#xC131;&#xC758; &#xCEE8;&#xD2B8;&#xB864;&#xC744; &#xD3EC;&#xD568; &#xD558; &#xC5EC; &#xB178;&#xCE58; &#xB9AC;&#xAC04;&#xB4DC;&#xB85C; Deltad&#xC758; &#xC77C;&#xBD80; &#xC54C;&#xB824;&#xC9C4;&#xB41C; &#xAE30;&#xB2A5; &#xC218;&#xC9C1;&#xC778; &#xB098;&#xD0C0;&#xB0A9;&#xB2C8;&#xB2E4;. &#xADF8;&#xB7EC;&#xB098; &#xADF8;&#xB4E4;&#xC740; &#xB378;&#xD0C0; &#xB3D9;&#xBC29; &#xC0C1;&#xD638; &#xC791;&#xC6A9; &#xC2E0;&#xACBD; &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158; &#xCEE8;&#xD2B8;&#xB864;&#xC5D0; &#xC77C;&#xBD80;&#xB97C; &#xC7AC;&#xC0DD;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4; &#xC81C;&#xC548; &#xB4F1; &#xCABD; &#xC2E0;&#xACBD; &#xD29C;&#xBE0C;&#xC5D0; Rohon &#xC218;&#xC5FC; &#xC2E0;&#xACBD; &#xC138;&#xD3EC;&#xC758; &#xBE44;&#xC815;&#xC0C1;&#xC801;&#xC778; &#xBD84;&#xD3EC;&#xB97C; &#xD45C;&#xC2DC;.

&#xB378;&#xD0C0; &#xB2E8;&#xBC31;&#xC9C8;&#xACFC; &#xB3D9;&#xBC29; &#xB2E8;&#xBC31;&#xC9C8;: &#xC138;&#xD3EC;&#xB0B4; &#xBE44; &#xACC4; &#xBD84;&#xC790;&#xC640; zebrafish &#xAC1C;&#xBC1C;&#xC758; &#xC758;&#xBBF8;&#xC640; &#xB178;&#xCE58; ligands&#xC758; &#xC0C1;&#xD638; &#xC791;&#xC6A9;.

Prote&#xED;nas Delta activar a Notch a trav&#xE9;s de una reacci&#xF3;n de uni&#xF3;n que depende de sus dominios extracelulares, pero los intracelulares (C-terminal) los dominios de los Deltas tambi&#xE9;n tienen funciones importantes. Todas las clases de vertebrados poseen un subconjunto de prote&#xED;nas Delta con un motivo conservado * ATEV en sus extremos C. Estos son los deltas ATEV Delta1 y Delta4 en los mam&#xED;feros y DeltaD y DeltaC en el pez cebra. Se demuestra que estos deltas asociarse con las prote&#xED;nas de andamiaje asociadas a la membrana MAGI1, MAGI2 y MAGI3, a trav&#xE9;s de una interacci&#xF3;n directa entre las terminales C de los Deltas y una espec&#xED;fica de dominio PDZ (PDZ4) de la Magis. En c&#xE9;lulas en cultivo y en los subconjuntos de c&#xE9;lulas en el embri&#xF3;n de pez cebra intacta, DeltaD MAGI1 y son co-localizada en la membrana plasm&#xE1;tica. La interacci&#xF3;n y la co-localizaci&#xF3;n puede ser abolida por la inyecci&#xF3;n de un morfolino que bloquea la reacci&#xF3;n de empalme del ARNm que da DeltaD la valina terminal, en la que la interacci&#xF3;n depende. Los embriones tratados de esta manera parece normal con respecto a algunas de las funciones conocidas de DeltaD como un ligando de Notch, incluyendo el control de la segmentaci&#xF3;n somite, la neurog&#xE9;nesis y la formaci&#xF3;n de hypochord. Ellos, sin embargo, muestran una distribuci&#xF3;n an&#xF3;mala de las neuronas-Barba Rohon en el tubo neural dorsal, lo que sugiere que la interacci&#xF3;n del delta-REYES MAGOS puede jugar alg&#xFA;n papel en el control de la migraci&#xF3;n neuronal.

Delta Las prote&#xED;nas y las prote&#xED;nas de los Reyes Magos: una interacci&#xF3;n de ligandos de Notch con las mol&#xE9;culas intracelulares Andamios y su significado para el Desarrollo de pez cebra

The transparency of the juvenile zebrafish and its genetic advantages make it an attractive model for study of cell turnover in the gut. BrdU labelling shows that the gut epithelium is renewed in essentially the same way as in mammals: the villi are lined with non-dividing differentiated cells, while cell division is confined to the intervillus pockets. New cells produced in the pockets take about 4 days to migrate out to the tips of the villi, where they die. We have generated monoclonal antibodies to identify the absorptive and secretory cells in the epithelium, and we have used these antibodies to examine the part that Delta-Notch signalling plays in producing the diversity of intestinal cell types. Several Notch receptors and ligands are expressed in the gut. In particular, the Notch ligand DeltaD (Delta1 in the mouse) is expressed in cells of the secretory lineage. In an aei mutant, where DeltaD is defective, secretory cells are overproduced. In mind bomb (mib), where all Delta-Notch signalling is believed to be blocked, almost all the cells in the 3-day gut epithelium adopt a secretory character. Thus, secretory differentiation appears to be the default in the absence of Notch activation, and lateral inhibition mediated by Delta-Notch signalling is required to generate a balanced mixture of absorptive and secretory cells. These findings demonstrate the central role of Notch signalling in the gut stem-cell system and establish the zebrafish as a model for study of the mechanisms controlling renewal of gut epithelium.

Delta-Notch signalling controls commitment to a secretory fate in the zebrafish intestine.

Notch signalling by the ligand Delta-like 4 (Dll4) is essential for normal vascular remodelling, yet the precise way in which the pathway influences the behaviour of endothelial cells remains a mystery. Using the embryonic zebrafish, we show that, when Dll4-Notch signalling is defective, endothelial cells continue to migrate and proliferate when they should normally stop these processes. Artificial overactivation of the Notch pathway has opposite consequences. When vascular endothelial growth factor (Vegf) signalling and Dll4-Notch signalling are both blocked, the endothelial cells remain quiescent. Thus, Dll4-Notch signalling acts as an angiogenic ;off' switch by making endothelial cells unresponsive to Vegf.

Endothelial signalling by the Notch ligand Delta-like 4 restricts angiogenesis.

Notch signalling is well-known to mediate lateral inhibition in inner ear sensory patches, so as to generate a balanced mixture of sensory hair cells and supporting cells. Recently, however, we have found that ectopic Notch activity at an early stage can induce the formation of ectopic sensory patches. This suggests that Notch activity may have two different functions in normal ear development, acting first to promote the formation of the prosensory patches, and then later to regulate hair-cell production within the patches. The Notch ligand Serrate1 (Jag1 in mouse and humans) is expressed in the patches from an early stage and may provide Notch activation during the prosensory phase. Here, we test whether Notch signalling is actually required for prosensory patch development. When we block Notch activation in the chick embryo using the gamma-secretase inhibitor DAPT, we see a complete loss of prosensory epithelial cells in the anterior otocyst, where they are diverted into a neuroblast fate via failure of Delta1-dependent lateral inhibition. The cells of the posterior prosensory patch remain epithelial, but expression of Sox2 and Bmp4 is drastically reduced. Expression of Serrate1 here is initially almost normal, but subsequently regresses. The patches of sensory hair cells that eventually develop are few and small. We suggest that, in normal development, factors other than Notch activity initiate Serrate1 expression. Serrate1, by activating Notch, then drives the expression of Sox2 and Bmp4, as well as expression of the Serrate1 gene itself. The positive feedback maintains Notch activation and thereby preserves and perhaps extends the prosensory state, leading eventually to the development of normal sensory patches.

Notch signalling is needed to maintain, but not to initiate, the formation of prosensory patches in the chick inner ear.

&#x6211;&#x4EEC;&#x63CF;&#x8FF0;&#x4E86;&#x751F;&#x4EA7;&#x548C;&#x5B9A;&#x6027;&#x4E24;&#x79CD;&#x5355;&#x514B;&#x9686;&#x6297;&#x4F53;&#x3001; zdc2 &#x548C; zdd2&#xFF0C;&#x5206;&#x522B;&#x9488;&#x5BF9; DeltaC &#x548C; DeltaD&#xFF0C;&#x6591;&#x9A6C;&#x9C7C;&#x7684;&#x69FD;&#x53E3;&#x914D;&#x4F53;&#x3002;&#x6211;&#x4EEC;&#x4F7F;&#x7528;&#x6211;&#x4EEC;&#x7684;&#x6297;&#x4F53;&#x663E;&#x793A;&#x8FD9;&#x4E9B;&#x4E09;&#x89D2;&#x6D32;&#x86CB;&#x767D;&#x8D28;&#x53EF;&#x4EE5;&#x7ED1;&#x5B9A;&#x5230;&#x53E6;&#x4E00;&#x4E2A;&#xFF0C;&#x76F4;&#x7ACB;&#x4EBA;&#x548C; heterophilically&#xFF0C;&#x5E76;&#x7814;&#x7A76;&#x5728;&#x6591;&#x9A6C;&#x9C7C;&#x4E2D;&#x67A2;&#x795E;&#x7ECF;&#x7CFB;&#x7EDF;&#x548C; presomitic &#x4E2D;&#x80DA;&#x5C42; (PSM) DeltaC &#x548C; DeltaD &#x7684;&#x672C;&#x5730;&#x5316;&#x3002;&#x6211;&#x4EEC;&#x5728;&#x4E2D;&#x67A2;&#x795E;&#x7ECF;&#x7CFB;&#x7EDF;&#x4E2D;&#x7684;&#x7814;&#x7A76;&#x7ED3;&#x679C;&#x5F88;&#x5927;&#x7A0B;&#x5EA6;&#x4E0A;&#x786E;&#x8BA4;&#x671F;&#x671B;&#x4ECE;&#x4EE5;&#x5F80;&#x7684;&#x7814;&#x7A76;&#xFF0C;&#x4F46;&#x5728; PSM &#x4E2D;&#xFF0C;&#x6211;&#x4EEC;&#x770B;&#x5230;&#x610F;&#x5916;&#x7684;&#x6A21;&#x5F0F;&#xFF0C;&#x672C;&#x5730;&#x5316;&#x7684; DeltaD &#x7684; DeltaC &#x7684;&#x8868;&#x8FBE;&#x6C34;&#x5E73;&#x800C;&#x5F02;&#xFF1A; &#x5728;&#x524D; PSM&#xFF0C;&#x5176;&#x4E2D; DeltaC &#x662F;&#x5145;&#x8DB3;&#x7684;&#x4E24;&#x79CD;&#x86CB;&#x767D; colocalised &#x5728;&#x7EC6;&#x80DE;&#x5185;&#x7684; puncta&#xFF0C;&#x4F46;&#x5728;&#x540E; PSM&#xFF0C;&#x5176;&#x4E2D; DeltaC &#x662F;&#x5728;&#x8F83;&#x4F4E;&#x7EA7;&#x522B;&#x4E2D;&#xFF0C;DeltaD &#x662F;&#x4E3B;&#x8981;&#x7EC6;&#x80DE;&#x8868;&#x9762;&#x4E0A;&#x770B;&#x5230;&#x7684;&#x3002;DeltaC &#x5F3A;&#x8FEB;&#x8FC7;&#x8868;&#x8FBE;&#x964D;&#x4F4E;&#x540E;&#x7684; PSM &#xFF1B; &#x5728;&#x7EC6;&#x80DE;&#x8868;&#x9762;&#x4E0A;&#x7684; DeltaD &#x91CF;&#x76F8;&#x53CD;&#xFF0C;DeltaC &#x7684;&#x529F;&#x80FD;&#x635F;&#x5931;&#x7684;&#x7A81;&#x53D8;&#x589E;&#x52A0;&#x524D; PSM &#x7EC6;&#x80DE;&#x8868;&#x9762;&#x4E0A;&#x7684; DeltaD &#x91CF;&#x3002;&#x8FD9;&#x4E9B;&#x7814;&#x7A76;&#x7ED3;&#x679C;&#x8868;&#x660E;&#x957F;&#x671F;&#x56F0;&#x60D1;&#x5173;&#x4E8E;&#x804C;&#x80FD;&#x4E24;&#x4E2A;&#x4E09;&#x89D2;&#x6D32;&#x86CB;&#x767D;&#x4F53;&#x8282;&#x5206;&#x5272;&#x65F6;&#x949F; &mdash; &mdash; &#x505A;&#x51FA;&#x89E3;&#x91CA;&#xFF0C;&#x57FA;&#x4E8E;&#x4ED6;&#x4EEC;&#x5173;&#x8054; heterophilically &#x8981;&#x6FC0;&#x6D3B;&#x7684;&#x69FD;&#x53E3;&#x7684;&#x547D;&#x9898;&#x7684;&#x89E3;&#x91CA;&#x3002;

DeltaC &#x548C; DeltaD &#x7684;&#x69FD;&#x53E3;&#x914D;&#x4F53;&#x5728;&#x6591;&#x9A6C;&#x9C7C;&#x5206;&#x5272;&#x65F6;&#x949F;&#x4F5C;&#x4E3A;&#x4E92;&#x52A8;&#x3002;

We describe the production and characterisation of two monoclonal antibodies, zdc2 and zdd2, directed against the zebrafish Notch ligands DeltaC and DeltaD, respectively. We use our antibodies to show that these Delta proteins can bind to one another homo- and heterophilically, and to study the localisation of DeltaC and DeltaD in the zebrafish nervous system and presomitic mesoderm (PSM). Our findings in the nervous system largely confirm expectations from previous studies, but in the PSM we see an unexpected pattern in which the localisation of DeltaD varies according to the level of expression of DeltaC: in the anterior PSM, where DeltaC is plentiful, the two proteins are colocalised in intracellular puncta, but in the posterior PSM, where DeltaC is at a lower level, DeltaD is seen mainly on the cell surface. Forced overexpression of DeltaC reduces the amount of DeltaD on the cell surface in the posterior PSM; conversely, loss-of-function mutation of DeltaC increases the amount of DeltaD on the cell surface in the anterior PSM. These findings suggest an explanation for a long-standing puzzle regarding the functions of the two Delta proteins in the somite segmentation clock--an explanation that is based on the proposition that they associate heterophilically to activate Notch.

DeltaC and DeltaD interact as Notch ligands in the zebrafish segmentation clock.

Nous d&#xE9;crivons la production et la caract&#xE9;risation de deux anticorps monoclonaux, et zdc2 zdd2, dirig&#xE9;s contre les ligands de Notch poisson-z&#xE8;bre et DeltaC DeltaD, respectivement. Nous utilisons nos anticorps de montrer que ces prot&#xE9;ines peuvent se lier &#xE0; Delta un de l&#x26;#39;autre homo-et heterophilically, et d&#x26;#39;&#xE9;tudier la localisation de DeltaC et DeltaD dans le syst&#xE8;me nerveux et le poisson-z&#xE8;bre m&#xE9;soderme presomitic (PSM). Nos r&#xE9;sultats dans le syst&#xE8;me nerveux confirment largement les attentes des &#xE9;tudes pr&#xE9;c&#xE9;dentes, mais dans le PSM, nous voyons un motif inattendu dans lequel la localisation des DeltaD varie selon le niveau d&#x26;#39;expression de DeltaC: dans le PSM ant&#xE9;rieure, o&#xF9; DeltaC est abondante, les deux les prot&#xE9;ines sont dans colocalised puncta intracellulaire, mais dans le PSM post&#xE9;rieure, o&#xF9; DeltaC est &#xE0; un niveau inf&#xE9;rieur, DeltaD est vu essentiellement sur la surface cellulaire. Surexpression forc&#xE9;e des DeltaC r&#xE9;duit la quantit&#xE9; de DeltaD sur la surface cellulaire dans le PSM post&#xE9;rieure, &#xE0; l&#x26;#39;inverse, la perte de fonction de la mutation de DeltaC augmente la quantit&#xE9; de DeltaD sur la surface cellulaire dans le PSM ant&#xE9;rieure. Ces r&#xE9;sultats sugg&#xE8;rent une explication pour une &#xE9;nigme de longue date en ce qui concerne les fonctions des deux prot&#xE9;ines Delta de l&#x26;#39;horloge de segmentation somite - une explication qui est bas&#xE9; sur la proposition qu&#x26;#39;ils associent heterophilically pour activer Notch.

DeltaC et DeltaD interagir comme ligands de Notch dans l&#x26;#39;horloge de segmentation poisson z&#xE8;bre

Wir beschreiben die Herstellung und Charakterisierung von zwei monoklonale Antik&ouml;rper, zdc2 und zdd2, bzw. gegen die Zebrafisch-Notch-Liganden DeltaC und DeltaD, gerichtet. Wir nutzen unsere Antik&ouml;rper zu zeigen, dass diese Delta-Proteine binden k&ouml;nnen, einander Homo- und Heterophilically und die Lokalisation von DeltaC und DeltaD im Zebrafisch-Nervensystem und presomitic Mesoderm (PSM) zu studieren. Unsere Ergebnisse im Nervensystem weitgehend Erwartungen von fr&uuml;heren Studien best&auml;tigen, aber in der PSM sehen wir eine unerwartete Muster, in denen die Lokalisation des DeltaD variiert nach der Ebene des Ausdrucks von DeltaC je: in der vorderen PSM, wo DeltaC reichlich vorhanden ist, sind die zwei Proteine in intrazellul&auml;ren Puncta, sondern in den hinteren PSM, wo DeltaC ist auf einem niedrigeren Niveau colocalisedDeltaD wird haupts&auml;chlich auf der Zelloberfl&auml;che gesehen. Erzwungene eine &Uuml;berexpression von DeltaC reduziert den DeltaD auf der Zelloberfl&auml;che in den hinteren PSM; umgekehrt erh&ouml;ht Loss of Function Mutation des DeltaC die Menge des DeltaD auf der Zelloberfl&auml;che in der vorderen PSM. Diese Forschungsergebnisse legen nahe, eine Erkl&auml;rung f&uuml;r eine langj&auml;hrige Puzzle &uuml;ber die Funktionen der beiden Delta-Proteine in der Somiten Segmentierung Uhr--eine Erkl&auml;rung, die auf die Aussage, dass sie Heterophilically verbinden um Kerbe zu aktivieren.

DeltaC und DeltaD interagieren als Notch-Liganden in der Zebrafisch-Segmentierung-Uhr.

Descriviamo la produzione e la caratterizzazione di due anticorpi monoclonali, zdc2 e zdd2, diretto contro i ligandi tacca zebrafish DeltaC e DeltaD, rispettivamente. Usiamo i nostri anticorpi per mostrare che queste proteine Delta possono legarsi l&#39;uno a altro homo - e heterophilically e di studiare la localizzazione di DeltaC e DeltaD nel sistema nervoso zebrafish e mesoderm presomitic (PSM). I nostri risultati nel sistema nervoso in gran parte confermano le aspettative da studi precedenti, ma il PSM vediamo un motivo imprevisto in cui la localizzazione di DeltaD varia a seconda del livello di espressione di DeltaC: nel PSM anteriore, dove DeltaC &egrave; abbondante, sono colocalised le due proteine intracellulare puncta, ma il PSM posteriore, dove DeltaC &egrave; a un livello inferioreDeltaD &egrave; visto principalmente sulla superficie della cellula. Sovraespressione forzata di DeltaC riduce la quantit&agrave; di DeltaD sulla superficie delle cellule nel PSM posteriore; al contrario, mutazione di perdita di funzione di DeltaC aumenta la quantit&agrave; di DeltaD sulla superficie delle cellule nel PSM anteriore. Questi risultati suggeriscono una spiegazione per un puzzle di vecchia data per quanto riguarda le funzioni delle due proteine Delta nell&#39;orologio di segmentazione somite - una spiegazione che si basa sulla proposizione che associano heterophilically per attivare la tacca.

DeltaC e DeltaD interagire come ligandi tacca nell&#39;orologio di segmentazione zebrafish.

&#x6211;&#x3005;&#x306F;&#x3001;&#x305D;&#x308C;&#x305E;&#x308C;&#x3001;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;Notch&#x306E;&#x30EA;&#x30AC;&#x30F3;&#x30C9;DeltaC&#x3068;DeltaD&#x306B;&#x5BFE;&#x3059;&#x308B;2&#x3064;&#x306E;&#x30E2;&#x30CE;&#x30AF;&#x30ED;&#x30FC;&#x30CA;&#x30EB;&#x6297;&#x4F53;&#x3001;ZDC2&#x3068;zdd2&#x306E;&#x751F;&#x7523;&#x304A;&#x3088;&#x3073;&#x7279;&#x6027;&#x306B;&#x3064;&#x3044;&#x3066;&#x8AAC;&#x660E;&#x3057;&#x307E;&#x3059;&#x3002;&#x6211;&#x3005;&#x306F;&#x3001;&#x3053;&#x308C;&#x3089;&#x306E;&#x30C7;&#x30EB;&#x30BF;&#x306E;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x304C;&#x4E92;&#x3044;&#x306B;&#x30DB;&#x30E2;&#x3068;heterophilically&#x306B;&#x30D0;&#x30A4;&#x30F3;&#x30C9;&#x3059;&#x308B;&#x3053;&#x3068;&#x304C;&#x3067;&#x304D;&#x3001;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x795E;&#x7D4C;&#x7CFB;&#x3068;&#x524D;&#x4F53;&#x7BC0;&#x4E2D;&#x80DA;&#x8449;&#xFF08;PSM&#xFF09;&#x3067;DeltaC&#x3068;DeltaD&#x306E;&#x5C40;&#x5728;&#x3092;&#x691C;&#x8A0E;&#x3059;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x3059;&#x305F;&#x3081;&#x306B;&#x79C1;&#x305F;&#x3061;&#x306E;&#x6297;&#x4F53;&#x3092;&#x4F7F;&#x7528;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x795E;&#x7D4C;&#x7CFB;&#x306E;&#x6211;&#x3005;&#x306E;&#x8ABF;&#x67FB;&#x7D50;&#x679C;&#x306F;&#x3001;&#x4E3B;&#x306B;&#x3053;&#x308C;&#x307E;&#x3067;&#x306E;&#x7814;&#x7A76;&#x304B;&#x3089;&#x306E;&#x671F;&#x5F85;&#x3092;&#x78BA;&#x8A8D;&#x3059;&#x308B;&#x304C;&#x3001;PSM&#x3067;&#x6211;&#x3005;&#x306F;DeltaD&#x306E;&#x5C40;&#x5728;&#x304C;DeltaC&#x306E;&#x767A;&#x73FE;&#x306E;&#x30EC;&#x30D9;&#x30EB;&#x306B;&#x5FDC;&#x3058;&#x3066;&#x5909;&#x5316;&#x3059;&#x308B;&#x4E88;&#x671F;&#x3057;&#x306A;&#x3044;&#x30D1;&#x30BF;&#x30FC;&#x30F3;&#x3092;&#x53C2;&#x7167;&#x3057;&#x3066;&#x304F;&#x3060;&#x3055;&#x3044;&#x3002;&#x524D;PSM&#x306B;&#x306F;&#x3001;DeltaC&#x304C;&#x8C4A;&#x5BCC;&#x3067;&#x3042;&#x308A;&#x3001;2&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x306F;&#x7D30;&#x80DE;&#x5185;&#x306E;&#x6D99;&#x70B9;&#x306B;colocalised&#x3055;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x304C;&#x3001;DeltaC&#x304C;&#x4F4E;&#x3044;&#x30EC;&#x30D9;&#x30EB;&#x3067;&#x3042;&#x308B;&#x5F8C;&#x90E8;PSM&#x3067;&#x3001;DeltaD&#x306F;&#x3001;&#x7D30;&#x80DE;&#x8868;&#x9762;&#x4E0A;&#x306B;&#x4E3B;&#x306B;&#x898B;&#x3089;&#x308C;&#x3066;&#x3044;&#x308B;&#x3002; DeltaC&#x306E;&#x5F37;&#x5236;&#x904E;&#x5270;&#x767A;&#x73FE;&#x306F;&#x5F8C;&#x90E8;PSM&#x306B;&#x304A;&#x3051;&#x308B;&#x7D30;&#x80DE;&#x8868;&#x9762;&#x4E0A;&#x306B;DeltaD&#x306E;&#x91CF;&#x3092;&#x6E1B;&#x3089;&#x3057;&#x3001;&#x9006;&#x306B;DeltaC&#x306E;&#x6A5F;&#x80FD;&#x55AA;&#x5931;&#x5909;&#x7570;&#x306F;&#x524D;PSM&#x306B;&#x304A;&#x3051;&#x308B;&#x7D30;&#x80DE;&#x8868;&#x9762;&#x4E0A;&#x306B;DeltaD&#x306E;&#x91CF;&#x304C;&#x5897;&#x52A0;&#x3057;&#x307E;&#x3059;&#x3002;&#x5F7C;&#x3089;&#x306F;&#x30CE;&#x30C3;&#x30C1;&#x3092;&#x6709;&#x52B9;&#x306B;&#x3059;&#x308B;&#x306B;&#x306F;heterophilically&#x95A2;&#x9023;&#x4ED8;&#x3051;&#x308B;&#x3068;&#x3044;&#x3046;&#x547D;&#x984C;&#x306B;&#x57FA;&#x3065;&#x3044;&#x3066;&#x8AAC;&#x660E; - &#x3053;&#x308C;&#x3089;&#x306E;&#x77E5;&#x898B;&#x306F;&#x3001;&#x4F53;&#x7BC0;&#x30BB;&#x30B0;&#x30E1;&#x30F3;&#x30C6;&#x30FC;&#x30B7;&#x30E7;&#x30F3;&#x30AF;&#x30ED;&#x30C3;&#x30AF;&#x306E;2&#x30C7;&#x30EB;&#x30BF;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x306E;&#x6A5F;&#x80FD;&#x306B;&#x95A2;&#x3059;&#x308B;&#x9577;&#x671F;&#x7684;&#x306A;&#x30D1;&#x30BA;&#x30EB;&#x306E;&#x8AAC;&#x660E;&#x3092;&#x793A;&#x5506;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;

DeltaC&#x3068;DeltaD&#x306F;&#x3001;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x5206;&#x7BC0;&#x6642;&#x8A08;&#x306B;&#x304A;&#x3051;&#x308B;Notch&#x30EA;&#x30AC;&#x30F3;&#x30C9;&#x306E;&#x3088;&#x3046;&#x306B;&#x76F8;&#x4E92;&#x4F5C;&#x7528;

&#xC6B0;&#xB9AC;&#xB294; &#xC0DD;&#xC0B0; &#xBC0F; &#xD2B9;&#xC131; 2 &#xB2E8;&#xC77C; &#xD074;&#xB860; &#xD56D; &#xCCB4;, zdc2, zdd2, &#xAC01;&#xAC01; Deltac&#xC640; DeltaD, zebrafish &#xB178;&#xCE58; ligands&#xC5D0; &#xB300; &#xD55C; &#xAC10;&#xB3C5;&#xC758; &#xC124;&#xBA85;. &#xC6B0;&#xB9AC; &#xD638;&#xBAA8;-&#xBC0F; heterophilically, &#xB378;&#xD0C0; &#xB2E8;&#xBC31;&#xC9C8;&#xC774; &#xC11C;&#xB85C; &#xBC14;&#xC778;&#xB529;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4; &#xAC8C;&#xC7AC; &#xD558; &#xACE0; zebrafish &#xC2E0; &#xACBD;&#xACC4;&#xC640; presomitic mesoderm (PSM)&#xC5D0;&#xC11C; DeltaC &#xBC0F; Deltad&#xC758; &#xD604;&#xC9C0;&#xD654; &#xC5F0;&#xAD6C; &#xC6B0;&#xB9AC;&#xC758; &#xD56D; &#xCCB4;&#xB97C; &#xC0AC;&#xC6A9; &#xD569;&#xB2C8;&#xB2E4;. &#xC2E0; &#xACBD;&#xACC4;&#xC5D0;&#xC11C; &#xC6B0;&#xB9AC;&#xC758; &#xC5F0;&#xAD6C; &#xACB0;&#xACFC; &#xB300;&#xBD80;&#xBD84; &#xC774;&#xC804; &#xC5F0;&#xAD6C;&#xC5D0;&#xC11C; &#xAE30;&#xB300;&#xB97C; &#xD655;&#xC778; &#xD558;&#xC9C0;&#xB9CC; PSM&#xC5D0;&#xC11C; &#xC6B0;&#xB9AC;&#xB294; Deltad&#xC758; &#xD604;&#xC9C0;&#xD654; Deltac&#xC758; &#xD45C;&#xD604; &#xC218;&#xC900;&#xC5D0; &#xB530;&#xB77C; &#xB2E4;&#xB985;&#xB2C8;&#xB2E4; &#xC608;&#xAE30;&#xCE58; &#xC54A;&#xC740; &#xD328;&#xD134; &#xBCFC;: &#xC55E;&#xCABD;&#xC5D0; PSM, &#xC5B4;&#xB514; Deltac&#xC740; &#xD48D;&#xBD80;, &#xC138;&#xD3EC;&#xB0B4; puncta, &#xD558;&#xC9C0;&#xB9CC; &#xB0AE;&#xC740; &#xC218;&#xC900;&#xC5D0;&#xC11C; Deltac&#xAC00; &#xD6C4;&#xBD80; PSM &#xB450; &#xB2E8;&#xBC31;&#xC9C8;&#xC774; colocalised&#xB294;DeltaD &#xC138;&#xD3EC; &#xD45C;&#xBA74;&#xC5D0; &#xC8FC;&#xB85C; &#xBCFC; &#xC218; &#xC788;&#xB2E4;. Deltac&#xC758; &#xAC15;&#xC81C; overexpression &#xD6C4;&#xBD80; PSM; &#xC138;&#xD3EC; &#xD45C;&#xBA74;&#xC5D0; Deltad&#xC758; &#xC591;&#xC744; &#xAC10;&#xC18C;&#xD569;&#xB2C8;&#xB2E4; &#xBC18;&#xB300;&#xB85C;, Deltac&#xC758; &#xAE30;&#xB2A5; &#xC190;&#xC2E4; &#xB3CC;&#xC5F0;&#xBCC0;&#xC774; &#xC55E;&#xCABD;&#xC5D0; PSM&#xC5D0; &#xC138;&#xD3EC; &#xD45C;&#xBA74;&#xC5D0; Deltad&#xC758; &#xC591;&#xC744; &#xB298;&#xB9BD;&#xB2C8;&#xB2E4;. &#xC774;&#xB7EC;&#xD55C; &#xC5F0;&#xAD6C; &#xACB0;&#xACFC; &#xC81C;&#xC548; somite &#xC138;&#xBD84;&#xD654; &#xC2DC;&#xACC4;-heterophilically &#xB178;&#xCE58; &#xD65C;&#xC131;&#xD654; &#xAD00;&#xB828; &#xBC95;&#xC548;&#xC5D0; &#xAE30;&#xCD08;&#xD55C; &#xC124;&#xBA85;&#xC5D0;&#xC5D0;&#xC11C; &#xB450; &#xB378;&#xD0C0; &#xB2E8;&#xBC31;&#xC9C8;&#xC758; &#xAE30;&#xB2A5;&#xC5D0; &#xAD00;&#xD55C; &#xC624;&#xB79C; &#xC218;&#xC218;&#xAED8;&#xB07C;&#xC5D0; &#xB300; &#xD55C; &#xC124;&#xBA85;.

DeltaC &#xBC0F; DeltaD zebrafish &#xC138;&#xBD84;&#xD654; &#xC2DC;&#xACC4;&#xC5D0; &#xB178;&#xCE58; ligands&#xB85C; &#xC0C1;&#xD638; &#xC791;&#xC6A9;&#xD569;&#xB2C8;&#xB2E4;.

Se describe la producci&#xF3;n y caracterizaci&#xF3;n de dos anticuerpos monoclonales, y zdc2 zdd2, dirigidos contra el pez cebra ligandos de Notch DeltaC y DeltaD, respectivamente. Usamos nuestros anticuerpos para demostrar que estas prote&#xED;nas Delta puede unirse el uno al otro homo-y heterophilically, y estudiar la localizaci&#xF3;n de DeltaC y DeltaD en el sistema nervioso del pez cebra y el mesodermo presomitic (PSM). Nuestros resultados en el sistema nervioso confirman en gran medida las expectativas de los estudios anteriores, pero en el PSM vemos un patr&#xF3;n inesperado en el que la localizaci&#xF3;n de DeltaD var&#xED;a seg&#xFA;n el nivel de expresi&#xF3;n de DeltaC: en el PSM anterior, donde DeltaC es abundante, los dos prote&#xED;nas se colocalizaban en puncta intracelular, pero en el PSM posterior, donde DeltaC est&#xE1; a un nivel inferior, DeltaD se observa principalmente en la superficie celular. Sobreexpresi&#xF3;n Forzada de DeltaC reduce la cantidad de DeltaD en la superficie celular en el PSM posterior, por el contrario, la p&#xE9;rdida de funci&#xF3;n de mutaci&#xF3;n DeltaC aumenta la cantidad de DeltaD en la superficie celular en el PSM anterior. Estos hallazgos sugieren una explicaci&#xF3;n para un misterio de larga data con respecto a las funciones de las dos prote&#xED;nas de Delta en el reloj de segmentaci&#xF3;n somite - una explicaci&#xF3;n que se basa en la proposici&#xF3;n de que se asocian heterophilically para activar a Notch.

DeltaC y DeltaD interaccionar como ligandos de Notch en el reloj de segmentaci&#xF3;n de pez cebra

The Notch signaling pathway controls differentiation of hair cells and supporting cells in the vertebrate inner ear. Here, we have investigated whether Numb, a known regulator of Notch activity in Drosophila, is involved in this process in the embryonic chick. The chicken homolog of Numb is expressed throughout the otocyst at early stages of development and is concentrated at the basal pole of the cells. It is asymmetrically allocated at some cell divisions, as in Drosophila, suggesting that it could act as a determinant inherited by one of the two daughter cells and favoring adoption of a hair-cell fate. To test the implication of Numb in hair cell fate decisions and the regulation of Notch signaling, we used different methods to overexpress Numb at different stages of inner ear development. We found that sustained or late Numb overexpression does not promote hair cell differentiation, and Numb does not prevent the reception of Notch signaling. Surprisingly, none of the Numb-overexpressing cells differentiated into hair cells, suggesting that high levels of Numb protein could interfere with intracellular processes essential for hair cell survival. However, when Numb was overexpressed early and more transiently during ear development, no effect on hair cell formation was seen. These results suggest that in the inner ear at least, Numb does not significantly repress Notch activity and that its asymmetric distribution in dividing precursor cells does not govern the choice between hair cell and supporting cell fates.

Numb is not a critical regulator of Notch-mediated cell fate decisions in the developing chick inner ear.

The strategy of enzymatic degradation of amino acids to deprive malignant cells of important nutrients is an established component of induction therapy of acute lymphoblastic leukemia. Here we show that acute myeloid leukemia (AML) cells from most patients with AML are deficient in a critical enzyme required for arginine synthesis, argininosuccinate synthetase-1 (ASS1). Thus, these ASS1-deficient AML cells are dependent on importing extracellular arginine. We therefore investigated the effect of plasma arginine deprivation using pegylated arginine deiminase (ADI-PEG 20) against primary AMLs in a xenograft model and in vitro. ADI-PEG 20 alone induced responses in 19 of 38 AMLs in vitro and 3 of 6 AMLs in vivo, leading to caspase activation in sensitive AMLs. ADI-PEG 20-resistant AMLs showed higher relative expression of ASS1 than sensitive AMLs. This suggests that the resistant AMLs survive by producing arginine through this metabolic pathway and ASS1 expression could be used as a biomarker for response. Sensitive AMLs showed more avid uptake of arginine from the extracellular environment consistent with their auxotrophy for arginine. The combination of ADI-PEG 20 and cytarabine chemotherapy was more effective than either treatment alone resulting in responses in 6 of 6 AMLs tested in vivo. Our data show that arginine deprivation is a reasonable strategy in AML that paves the way for clinical trials.

Arginine deprivation using pegylated arginine deiminase has activity against primary acute myeloid leukemia cells in vivo.

Characteristics of human primary mantle cell lymphoma engraftment in NSG mice.

Cord blood (CB) is increasingly used as a source of hematopoietic stem cells (HSC) for transplantation. Low incidence and severity of graft-versus-host disease (GvHD) and a robust graft-versus-leukemia (GvL) effect are observed following CB transplantation (CBT). However, its main disadvantages are a limited number of HSC per unit, delayed immune reconstitution and a higher incidence of infection. Unmanipulated grafts contain accessory cells that may facilitate HSC engraftment. Therefore, the effects of accessory cells, particularly natural killer (NK) cells, on human CB HSC (CBSC) functions were assessed in vitro and in vivo. CBSC cultured with autologous CB NK cells showed higher levels of CXCR4 expression, a higher migration index and a higher number of colony forming units (CFU) after short-term and long-term cultures. We found that CBSC secreted CXCL9 following interaction with CB NK cells. In addition, recombinant CXCL9 increased CBSC clonogenicity, recapitulating the effect observed of CB NK cells on CBSC. Moreover, the co-infusion of CBSC with CB NK cells led to a higher level of CBSC engraftment in NSG mouse model. The results presented in this work offer the basis for an alternative approach to enhance HSC engraftment that could improve the outcome of CBT.

Linda Ariza-McNaughton

Haematopoietic Stem Cell Laboratory

The Francis Crick Institute

Bioengineering of Humanized Bone Marrow Microenvironments in Mouse and Their Visualization by Live Imaging

Linda Ariza-McNaughton

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Haematopoietic Stem Cell Laboratory

The Francis Crick Institute

Bioengineering of Humanized Bone Marrow Microenvironments in Mouse and Their Visualization by Live Imaging

Haematopoietic Stem Cell Laboratory