Manoj K Madhavan, F. DeMayo, J. Lydon, Niraj R. Joshi, A. Fazleabas, R. Arora
ABSTRACT The uterine luminal epithelium folds characteristically in mammals, including humans, horses and rodents. Improper uterine folding in horses results in pregnancy failure, but the precise function of folds remains unknown. Here, we uncover dynamic changes in the 3D uterine folding pattern during early pregnancy with the entire lumen forming pre-implantation transverse folds along the mesometrial-antimesometrial axis. Using a time course, we show that transverse folds are formed before embryo spacing, whereas implantation chambers form as the embryo begins attachment. Thus, folds and chambers are two distinct structures. Transverse folds resolve to form a flat implantation region, after which an embryo arrives at its center to attach and form the post-implantation chamber. Our data also suggest that the implantation chamber facilitates embryo rotation and its alignment along the uterine mesometrial-antimesometrial axis. Using WNT5A- and RBPJ-deficient mice that display aberrant folds, we show that embryos trapped in longitudinal folds display misalignment of the embryo-uterine axes, abnormal chamber formation and defective post-implantation morphogenesis. These mouse models with disrupted uterine folding provide an opportunity to understand uterine structure-based mechanisms that are crucial for implantation and pregnancy success. This article has an associated ‘The people behind the papers’ interview.
{"title":"Aberrant uterine folding in mice disrupts implantation chamber formation and alignment of embryo-uterine axes","authors":"Manoj K Madhavan, F. DeMayo, J. Lydon, Niraj R. Joshi, A. Fazleabas, R. Arora","doi":"10.1242/dev.200300","DOIUrl":"https://doi.org/10.1242/dev.200300","url":null,"abstract":"ABSTRACT The uterine luminal epithelium folds characteristically in mammals, including humans, horses and rodents. Improper uterine folding in horses results in pregnancy failure, but the precise function of folds remains unknown. Here, we uncover dynamic changes in the 3D uterine folding pattern during early pregnancy with the entire lumen forming pre-implantation transverse folds along the mesometrial-antimesometrial axis. Using a time course, we show that transverse folds are formed before embryo spacing, whereas implantation chambers form as the embryo begins attachment. Thus, folds and chambers are two distinct structures. Transverse folds resolve to form a flat implantation region, after which an embryo arrives at its center to attach and form the post-implantation chamber. Our data also suggest that the implantation chamber facilitates embryo rotation and its alignment along the uterine mesometrial-antimesometrial axis. Using WNT5A- and RBPJ-deficient mice that display aberrant folds, we show that embryos trapped in longitudinal folds display misalignment of the embryo-uterine axes, abnormal chamber formation and defective post-implantation morphogenesis. These mouse models with disrupted uterine folding provide an opportunity to understand uterine structure-based mechanisms that are crucial for implantation and pregnancy success. This article has an associated ‘The people behind the papers’ interview.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90492986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pedro Ferreirinha, R. Pinheiro, J. Landry, N. Alves
ABSTRACT The thymus stroma constitutes a fundamental microenvironment for T-cell generation. Despite the chief contribution of thymic epithelial cells, recent studies emphasize the regulatory role of mesenchymal cells in thymic function. Mesenchymal progenitors are suggested to exist in the postnatal thymus; nonetheless, an understanding of their nature and the mechanism controlling their homeostasis in vivo remains elusive. We resolved two new thymic fibroblast subsets with distinct developmental features. Whereas CD140αβ+GP38+SCA-1− cells prevailed in the embryonic thymus and declined thereafter, CD140αβ+GP38+SCA-1+ cells emerged in the late embryonic period and predominated in postnatal life. The fibroblastic-associated transcriptional programme was upregulated in CD140αβ+GP38+SCA-1+ cells, suggesting that they represent a mature subset. Lineage analysis showed that CD140αβ+GP38+SCA-1+ maintained their phenotype in thymic organoids. Strikingly, CD140αβ+GP38+SCA-1− generated CD140αβ+GP38+SCA-1+, inferring that this subset harboured progenitor cell activity. Moreover, the abundance of CD140αβ+GP38+SCA-1+ fibroblasts was gradually reduced in Rag2−/− and Rag2−/−Il2rg−/− thymi, indicating that fibroblast maturation depends on thymic crosstalk. Our findings identify CD140αβ+GP38+SCA-1− as a source of fibroblast progenitors and define SCA-1 as a marker for developmental stages of thymic fibroblast differentiation.
{"title":"Identification of fibroblast progenitors in the developing mouse thymus","authors":"Pedro Ferreirinha, R. Pinheiro, J. Landry, N. Alves","doi":"10.1242/dev.200513","DOIUrl":"https://doi.org/10.1242/dev.200513","url":null,"abstract":"ABSTRACT The thymus stroma constitutes a fundamental microenvironment for T-cell generation. Despite the chief contribution of thymic epithelial cells, recent studies emphasize the regulatory role of mesenchymal cells in thymic function. Mesenchymal progenitors are suggested to exist in the postnatal thymus; nonetheless, an understanding of their nature and the mechanism controlling their homeostasis in vivo remains elusive. We resolved two new thymic fibroblast subsets with distinct developmental features. Whereas CD140αβ+GP38+SCA-1− cells prevailed in the embryonic thymus and declined thereafter, CD140αβ+GP38+SCA-1+ cells emerged in the late embryonic period and predominated in postnatal life. The fibroblastic-associated transcriptional programme was upregulated in CD140αβ+GP38+SCA-1+ cells, suggesting that they represent a mature subset. Lineage analysis showed that CD140αβ+GP38+SCA-1+ maintained their phenotype in thymic organoids. Strikingly, CD140αβ+GP38+SCA-1− generated CD140αβ+GP38+SCA-1+, inferring that this subset harboured progenitor cell activity. Moreover, the abundance of CD140αβ+GP38+SCA-1+ fibroblasts was gradually reduced in Rag2−/− and Rag2−/−Il2rg−/− thymi, indicating that fibroblast maturation depends on thymic crosstalk. Our findings identify CD140αβ+GP38+SCA-1− as a source of fibroblast progenitors and define SCA-1 as a marker for developmental stages of thymic fibroblast differentiation.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76198150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT The fibroblast growth factor (FGF) signalling pathway plays various roles during vertebrate embryogenesis, from mesoderm formation to brain patterning. This diversity of functions relies on the fact that vertebrates possess the largest FGF gene complement among metazoans. In the cephalochordate amphioxus, which belongs to the chordate clade together with vertebrates and tunicates, we have previously shown that the main role of FGF during early development is the control of rostral somite formation. Inhibition of this signalling pathway induces the loss of these structures, resulting in an embryo without anterior segmented mesoderm, as in the vertebrate head. Here, by combining several approaches, we show that the anterior presumptive paraxial mesoderm cells acquire an anterior axial fate when FGF signal is inhibited and that they are later incorporated in the anterior notochord. Our analysis of notochord formation in wild type and in embryos in which FGF signalling is inhibited also reveals that amphioxus anterior notochord presents transient prechordal plate features. Altogether, our results give insight into how changes in FGF functions during chordate evolution might have participated to the emergence of the complex vertebrate head.
{"title":"Functions of the FGF signalling pathway in cephalochordates provide insight into the evolution of the prechordal plate","authors":"Lydvina Meister, H. Escrivá, S. Bertrand","doi":"10.1242/dev.200252","DOIUrl":"https://doi.org/10.1242/dev.200252","url":null,"abstract":"ABSTRACT The fibroblast growth factor (FGF) signalling pathway plays various roles during vertebrate embryogenesis, from mesoderm formation to brain patterning. This diversity of functions relies on the fact that vertebrates possess the largest FGF gene complement among metazoans. In the cephalochordate amphioxus, which belongs to the chordate clade together with vertebrates and tunicates, we have previously shown that the main role of FGF during early development is the control of rostral somite formation. Inhibition of this signalling pathway induces the loss of these structures, resulting in an embryo without anterior segmented mesoderm, as in the vertebrate head. Here, by combining several approaches, we show that the anterior presumptive paraxial mesoderm cells acquire an anterior axial fate when FGF signal is inhibited and that they are later incorporated in the anterior notochord. Our analysis of notochord formation in wild type and in embryos in which FGF signalling is inhibited also reveals that amphioxus anterior notochord presents transient prechordal plate features. Altogether, our results give insight into how changes in FGF functions during chordate evolution might have participated to the emergence of the complex vertebrate head.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91279262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-13DOI: 10.1101/2022.05.12.491645
M. Hernández-Bejarano, G. Gestri, C. Monfries, Lisa Tucker, Elena I. Dragomir, I. H. Bianco, P. Bovolenta, Stephen W. Wilson, F. Cavodeassi
Appropriate patterning of the retina during embryonic development is assumed to underlie the establishment of spatially localised specialisations that mediate the perception of specific visual features. For instance, in zebrafish, an area involved in high acuity vision (HAA) is thought to be present in the ventro-temporal retina. Here we show that the interplay of the transcription factor Rx3 with Fibroblast Growth Factor and Hedgehog signals, initiates and restricts foxd1 expression to the prospective temporal retina, initiating naso-temporal regionalisation of the retina. Abrogation of FoxD1 results in the loss of temporal and expansion of nasal retinal character, and consequent absence of the HAA. These structural defects correlate with severe visual defects as assessed in optokinetic and optomotor response assays. In contrast, optokinetic responses are unaffected in the opposite condition in which nasal retinal character is lost at the expense of expanded temporal character. Our study indicates that the establishment of temporal retinal character during early retinal development is required for the specification of the HAA, and suggests a prominent role of the temporal retina in controlling specific visual functions. Summary statement This study provides a mechanistic link between eye patterning and the establishment of functionally distinct retinal regions and reveals the temporal retina preferentially controls specific aspects of visual function.
{"title":"Foxd1-dependent induction of a temporal retinal character is required for visual function","authors":"M. Hernández-Bejarano, G. Gestri, C. Monfries, Lisa Tucker, Elena I. Dragomir, I. H. Bianco, P. Bovolenta, Stephen W. Wilson, F. Cavodeassi","doi":"10.1101/2022.05.12.491645","DOIUrl":"https://doi.org/10.1101/2022.05.12.491645","url":null,"abstract":"Appropriate patterning of the retina during embryonic development is assumed to underlie the establishment of spatially localised specialisations that mediate the perception of specific visual features. For instance, in zebrafish, an area involved in high acuity vision (HAA) is thought to be present in the ventro-temporal retina. Here we show that the interplay of the transcription factor Rx3 with Fibroblast Growth Factor and Hedgehog signals, initiates and restricts foxd1 expression to the prospective temporal retina, initiating naso-temporal regionalisation of the retina. Abrogation of FoxD1 results in the loss of temporal and expansion of nasal retinal character, and consequent absence of the HAA. These structural defects correlate with severe visual defects as assessed in optokinetic and optomotor response assays. In contrast, optokinetic responses are unaffected in the opposite condition in which nasal retinal character is lost at the expense of expanded temporal character. Our study indicates that the establishment of temporal retinal character during early retinal development is required for the specification of the HAA, and suggests a prominent role of the temporal retina in controlling specific visual functions. Summary statement This study provides a mechanistic link between eye patterning and the establishment of functionally distinct retinal regions and reveals the temporal retina preferentially controls specific aspects of visual function.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79887854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-05DOI: 10.1101/2022.05.05.490765
E. Kugler, Isabel Bravo, Xhuljana Durmishi, S. Marcotti, Sara Beqiri, Alicia Carrington, B. Stramer, P. Mattar, R. MacDonald
Cell morphology is critical for all cell functions. This is particularly true for glial cells as they rely on their complex shape to contact and support neurons. However, methods to quantify complex glial cell shape accurately and reproducibly are lacking. To address this gap in quantification approaches, we developed an analysis pipeline called “GliaMorph”. GliaMorph is a modular image analysis toolkit developed to perform (i) image pre-processing, (ii) semi-automatic region-of-interest (ROI) selection, (iii) apicobasal texture analysis, (iv) glia segmentation, and (v) cell feature quantification. Müller Glia (MG) are the principal retinal glial cell type with a stereotypic shape linked to their maturation and physiological status. We here characterized MG on three levels, including (a) global image-level, (b) apicobasal texture, and (c) apicobasal vertical-to-horizontal alignment. Using GliaMorph, we show structural changes occurring in the developing retina. Additionally, we study the loss of cadherin2 in the zebrafish retina, as well as a glaucoma mouse disease model. The GliaMorph toolkit enables an in-depth understanding of MG morphology in the developing and diseased retina. Graphical Abstract Highlights Glial morphology is complex, making it challenging to accurately quantify 3D cell shape. We developed the GliaMorph toolkit for image pre-processing, glial segmentation, and quantification of Müller glial cells. Müller glia elaborate their morphology and rearrange subcellular features during embryonic development. GliaMorph accurately identifies subcellular changes in models with disrupted glia cells, including zebrafish cadherin2 loss of function and a mouse glaucoma model.
{"title":"GliaMorph: a modular image analysis toolkit to quantify Müller glial cell morphology","authors":"E. Kugler, Isabel Bravo, Xhuljana Durmishi, S. Marcotti, Sara Beqiri, Alicia Carrington, B. Stramer, P. Mattar, R. MacDonald","doi":"10.1101/2022.05.05.490765","DOIUrl":"https://doi.org/10.1101/2022.05.05.490765","url":null,"abstract":"Cell morphology is critical for all cell functions. This is particularly true for glial cells as they rely on their complex shape to contact and support neurons. However, methods to quantify complex glial cell shape accurately and reproducibly are lacking. To address this gap in quantification approaches, we developed an analysis pipeline called “GliaMorph”. GliaMorph is a modular image analysis toolkit developed to perform (i) image pre-processing, (ii) semi-automatic region-of-interest (ROI) selection, (iii) apicobasal texture analysis, (iv) glia segmentation, and (v) cell feature quantification. Müller Glia (MG) are the principal retinal glial cell type with a stereotypic shape linked to their maturation and physiological status. We here characterized MG on three levels, including (a) global image-level, (b) apicobasal texture, and (c) apicobasal vertical-to-horizontal alignment. Using GliaMorph, we show structural changes occurring in the developing retina. Additionally, we study the loss of cadherin2 in the zebrafish retina, as well as a glaucoma mouse disease model. The GliaMorph toolkit enables an in-depth understanding of MG morphology in the developing and diseased retina. Graphical Abstract Highlights Glial morphology is complex, making it challenging to accurately quantify 3D cell shape. We developed the GliaMorph toolkit for image pre-processing, glial segmentation, and quantification of Müller glial cells. Müller glia elaborate their morphology and rearrange subcellular features during embryonic development. GliaMorph accurately identifies subcellular changes in models with disrupted glia cells, including zebrafish cadherin2 loss of function and a mouse glaucoma model.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87483190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yan Li, Chao Tang, F. Liu, Caiying Zhu, Feng Liu, Ping Zhu, Lu Wang
ABSTRACT The earliest hematopoietic stem and progenitor cells (HSPCs) are generated from the ventral wall of the dorsal aorta, through endothelial-to-hematopoietic transition during vertebrate embryogenesis. Notch signaling is crucial for HSPC generation across vertebrates; however, the precise control of Notch during this process remains unclear. In the present study, we used multi-omics approaches together with functional assays to assess global DNA methylome dynamics during the endothelial cells to HSPCs transition in zebrafish, and determined that DNA methyltransferase 1 (Dnmt1) is essential for HSPC generation via repression of Notch signaling. Depletion of dnmt1 resulted in decreased DNA methylation levels and impaired HSPC production. Mechanistically, we found that loss of dnmt1 induced hypomethylation of Notch genes and consequently elevated Notch activity in hemogenic endothelial cells, thereby repressing the generation of HSPCs. This finding deepens our understanding of HSPC specification in vivo, which will provide helpful insights for designing new strategies for HSPC generation in vitro.
{"title":"DNA methylation safeguards the generation of hematopoietic stem and progenitor cells by repression of Notch signaling","authors":"Yan Li, Chao Tang, F. Liu, Caiying Zhu, Feng Liu, Ping Zhu, Lu Wang","doi":"10.1242/dev.200390","DOIUrl":"https://doi.org/10.1242/dev.200390","url":null,"abstract":"ABSTRACT The earliest hematopoietic stem and progenitor cells (HSPCs) are generated from the ventral wall of the dorsal aorta, through endothelial-to-hematopoietic transition during vertebrate embryogenesis. Notch signaling is crucial for HSPC generation across vertebrates; however, the precise control of Notch during this process remains unclear. In the present study, we used multi-omics approaches together with functional assays to assess global DNA methylome dynamics during the endothelial cells to HSPCs transition in zebrafish, and determined that DNA methyltransferase 1 (Dnmt1) is essential for HSPC generation via repression of Notch signaling. Depletion of dnmt1 resulted in decreased DNA methylation levels and impaired HSPC production. Mechanistically, we found that loss of dnmt1 induced hypomethylation of Notch genes and consequently elevated Notch activity in hemogenic endothelial cells, thereby repressing the generation of HSPCs. This finding deepens our understanding of HSPC specification in vivo, which will provide helpful insights for designing new strategies for HSPC generation in vitro.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80491604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanshu Wang, Arjun Venkatesh, Jiajia Xu, Mingxin Xu, John L. Williams, P. Smallwood, Aaron W. James, J. Nathans
ABSTRACT In central nervous system vascular endothelial cells, signaling via the partially redundant ligands WNT7A and WNT7B requires two co-activator proteins, GPR124 and RECK. WNT7A and RECK have been shown previously to play a role in limb development, but the mechanism of RECK action in this context is unknown. The roles of WNT7B and GPR124 in limb development have not been investigated. Using combinations of conventional and/or conditional loss-of-function alleles for mouse Wnt7a, Wnt7b, Gpr124 and Reck, including a Reck allele that codes for a protein that is specifically defective in WNT7A/WNT7B signaling, we show that reductions in ligand and/or co-activator function synergize to cause reduced and dysmorphic limb bone growth. Two additional limb phenotypes – loss of distal Lmx1b expression and ectopic growth of nail-like structures – occur with reduced Wnt7a/Wnt7b gene copy number and, respectively, with Reck mutations and with combined Reck and Gpr124 mutations. A third limb phenotype – bleeding into a digit – occurs with the most severe combinations of Wnt7a/Wnt7b, Reck and Gpr124 mutations. These data imply that the WNT7A/WNT7B-FRIZZLED-LRP5/LRP6-GPR124-RECK signaling system functions as an integral unit in limb development.
{"title":"The WNT7A/WNT7B/GPR124/RECK signaling module plays an essential role in mammalian limb development","authors":"Yanshu Wang, Arjun Venkatesh, Jiajia Xu, Mingxin Xu, John L. Williams, P. Smallwood, Aaron W. James, J. Nathans","doi":"10.1242/dev.200340","DOIUrl":"https://doi.org/10.1242/dev.200340","url":null,"abstract":"ABSTRACT In central nervous system vascular endothelial cells, signaling via the partially redundant ligands WNT7A and WNT7B requires two co-activator proteins, GPR124 and RECK. WNT7A and RECK have been shown previously to play a role in limb development, but the mechanism of RECK action in this context is unknown. The roles of WNT7B and GPR124 in limb development have not been investigated. Using combinations of conventional and/or conditional loss-of-function alleles for mouse Wnt7a, Wnt7b, Gpr124 and Reck, including a Reck allele that codes for a protein that is specifically defective in WNT7A/WNT7B signaling, we show that reductions in ligand and/or co-activator function synergize to cause reduced and dysmorphic limb bone growth. Two additional limb phenotypes – loss of distal Lmx1b expression and ectopic growth of nail-like structures – occur with reduced Wnt7a/Wnt7b gene copy number and, respectively, with Reck mutations and with combined Reck and Gpr124 mutations. A third limb phenotype – bleeding into a digit – occurs with the most severe combinations of Wnt7a/Wnt7b, Reck and Gpr124 mutations. These data imply that the WNT7A/WNT7B-FRIZZLED-LRP5/LRP6-GPR124-RECK signaling system functions as an integral unit in limb development.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83083009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samuel J Capon, Veronica Uribe, Nicole Dominado, O. Ehrlich, Kelly A. Smith
ABSTRACT The endocardium plays important roles in the development and function of the vertebrate heart; however, few molecular markers of this tissue have been identified and little is known about what regulates its differentiation. Here, we describe the Gt(SAGFF27C); Tg(4xUAS:egfp) line as a marker of endocardial development in zebrafish. Transcriptomic comparison between endocardium and pan-endothelium confirms molecular distinction between these populations and time-course analysis suggests differentiation as early as eight somites. To investigate what regulates endocardial identity, we employed npas4l, etv2 and scl loss-of-function models. Endocardial expression is lost in npas4l mutants, significantly reduced in etv2 mutants and only modestly affected upon scl loss-of-function. Bmp signalling was also examined: overactivation of Bmp signalling increased endocardial expression, whereas Bmp inhibition decreased expression. Finally, epistasis experiments showed that overactivation of Bmp signalling was incapable of restoring endocardial expression in etv2 mutants. By contrast, overexpression of either npas4l or etv2 was sufficient to rescue endocardial expression upon Bmp inhibition. Together, these results describe the differentiation of the endocardium, distinct from vasculature, and place npas4l and etv2 downstream of Bmp signalling in regulating its differentiation.
{"title":"Endocardial identity is established during early somitogenesis by Bmp signalling acting upstream of npas4l and etv2","authors":"Samuel J Capon, Veronica Uribe, Nicole Dominado, O. Ehrlich, Kelly A. Smith","doi":"10.1242/dev.190421","DOIUrl":"https://doi.org/10.1242/dev.190421","url":null,"abstract":"ABSTRACT The endocardium plays important roles in the development and function of the vertebrate heart; however, few molecular markers of this tissue have been identified and little is known about what regulates its differentiation. Here, we describe the Gt(SAGFF27C); Tg(4xUAS:egfp) line as a marker of endocardial development in zebrafish. Transcriptomic comparison between endocardium and pan-endothelium confirms molecular distinction between these populations and time-course analysis suggests differentiation as early as eight somites. To investigate what regulates endocardial identity, we employed npas4l, etv2 and scl loss-of-function models. Endocardial expression is lost in npas4l mutants, significantly reduced in etv2 mutants and only modestly affected upon scl loss-of-function. Bmp signalling was also examined: overactivation of Bmp signalling increased endocardial expression, whereas Bmp inhibition decreased expression. Finally, epistasis experiments showed that overactivation of Bmp signalling was incapable of restoring endocardial expression in etv2 mutants. By contrast, overexpression of either npas4l or etv2 was sufficient to rescue endocardial expression upon Bmp inhibition. Together, these results describe the differentiation of the endocardium, distinct from vasculature, and place npas4l and etv2 downstream of Bmp signalling in regulating its differentiation.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75926272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT In multicellular systems, cells communicate with adjacent cells to determine their positions and fates, an arrangement important for cellular development. Orientation of cell division, cell-cell interactions (i.e. attraction and repulsion) and geometric constraints are three major factors that define cell arrangement. In particular, geometric constraints are difficult to reveal in experiments, and the contribution of the local contour of the boundary has remained elusive. In this study, we developed a multicellular morphology model based on the phase-field method so that precise geometric constraints can be incorporated. Our application of the model to nematode embryos predicted that the amount of extra-embryonic space, the empty space within the eggshell that is not occupied by embryonic cells, affects cell arrangement in a manner dependent on the local contour and other factors. The prediction was validated experimentally by increasing the extra-embryonic space in the Caenorhabditis elegans embryo. Overall, our analyses characterized the roles of geometrical contributors, specifically the amount of extra-embryonic space and the local contour, on cell arrangements. These factors should be considered for multicellular systems.
{"title":"The extra-embryonic space and the local contour are crucial geometric constraints regulating cell arrangement","authors":"S. Seirin-Lee, Kazunori Yamamoto, A. Kimura","doi":"10.1242/dev.200401","DOIUrl":"https://doi.org/10.1242/dev.200401","url":null,"abstract":"ABSTRACT In multicellular systems, cells communicate with adjacent cells to determine their positions and fates, an arrangement important for cellular development. Orientation of cell division, cell-cell interactions (i.e. attraction and repulsion) and geometric constraints are three major factors that define cell arrangement. In particular, geometric constraints are difficult to reveal in experiments, and the contribution of the local contour of the boundary has remained elusive. In this study, we developed a multicellular morphology model based on the phase-field method so that precise geometric constraints can be incorporated. Our application of the model to nematode embryos predicted that the amount of extra-embryonic space, the empty space within the eggshell that is not occupied by embryonic cells, affects cell arrangement in a manner dependent on the local contour and other factors. The prediction was validated experimentally by increasing the extra-embryonic space in the Caenorhabditis elegans embryo. Overall, our analyses characterized the roles of geometrical contributors, specifically the amount of extra-embryonic space and the local contour, on cell arrangements. These factors should be considered for multicellular systems.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75704747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hannah Brunsdon, A. Brombin, Samuel J. Peterson, J. Postlethwait, E. Patton
ABSTRACT Melanocyte stem cells (McSCs) in zebrafish serve as an on-demand source of melanocytes during growth and regeneration, but metabolic programs associated with their activation and regenerative processes are not well known. Here, using live imaging coupled with scRNA-sequencing, we discovered that, during regeneration, quiescent McSCs activate a dormant embryonic neural crest transcriptional program followed by an aldehyde dehydrogenase (Aldh) 2 metabolic switch to generate progeny. Unexpectedly, although ALDH2 is well known for its aldehyde-clearing mechanisms, we find that, in regenerating McSCs, Aldh2 activity is required to generate formate – the one-carbon (1C) building block for nucleotide biosynthesis – through formaldehyde metabolism. Consequently, we find that disrupting the 1C cycle with low doses of methotrexate causes melanocyte regeneration defects. In the absence of Aldh2, we find that purines are the metabolic end product sufficient for activated McSCs to generate progeny. Together, our work reveals McSCs undergo a two-step cell state transition during regeneration, and that the reaction products of Aldh2 enzymes have tissue-specific stem cell functions that meet metabolic demands in regeneration.
{"title":"Aldh2 is a lineage-specific metabolic gatekeeper in melanocyte stem cells","authors":"Hannah Brunsdon, A. Brombin, Samuel J. Peterson, J. Postlethwait, E. Patton","doi":"10.1242/dev.200277","DOIUrl":"https://doi.org/10.1242/dev.200277","url":null,"abstract":"ABSTRACT Melanocyte stem cells (McSCs) in zebrafish serve as an on-demand source of melanocytes during growth and regeneration, but metabolic programs associated with their activation and regenerative processes are not well known. Here, using live imaging coupled with scRNA-sequencing, we discovered that, during regeneration, quiescent McSCs activate a dormant embryonic neural crest transcriptional program followed by an aldehyde dehydrogenase (Aldh) 2 metabolic switch to generate progeny. Unexpectedly, although ALDH2 is well known for its aldehyde-clearing mechanisms, we find that, in regenerating McSCs, Aldh2 activity is required to generate formate – the one-carbon (1C) building block for nucleotide biosynthesis – through formaldehyde metabolism. Consequently, we find that disrupting the 1C cycle with low doses of methotrexate causes melanocyte regeneration defects. In the absence of Aldh2, we find that purines are the metabolic end product sufficient for activated McSCs to generate progeny. Together, our work reveals McSCs undergo a two-step cell state transition during regeneration, and that the reaction products of Aldh2 enzymes have tissue-specific stem cell functions that meet metabolic demands in regeneration.","PeriodicalId":77105,"journal":{"name":"Development (Cambridge, England). Supplement","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84203916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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