scholarly journals Pharyngeal pouches provide a niche microenvironment for arch artery progenitor specification

Development ◽  
2020 ◽  
Vol 148 (2) ◽  
pp. dev192658
Author(s):  
Aihua Mao ◽  
Mingming Zhang ◽  
Linwei Li ◽  
Jie Liu ◽  
Guozhu Ning ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Crucial Role ◽  
Ectopic Expression ◽  
Dorsal Aorta ◽  
Pharyngeal Arch ◽  
Zebrafish Embryos ◽  
Pharyngeal Pouch ◽  
Functional Interaction ◽  
Smad Pathway ◽  
Pharyngeal Arch Arteries

ABSTRACTThe paired pharyngeal arch arteries (PAAs) are transient blood vessels connecting the heart with the dorsal aorta during embryogenesis. Although PAA malformations often occur along with pharyngeal pouch defects, the functional interaction between these adjacent tissues remains largely unclear. Here, we report that pharyngeal pouches are essential for PAA progenitor specification in zebrafish embryos. We reveal that the segmentation of pharyngeal pouches coincides spatiotemporally with the emergence of PAA progenitor clusters. These pouches physically associate with pharyngeal mesoderm in discrete regions and provide a niche microenvironment for PAA progenitor commitment by expressing BMP proteins. Specifically, pouch-derived BMP2a and BMP5 are the primary niche cues responsible for activating the BMP/Smad pathway in pharyngeal mesoderm, thereby promoting progenitor specification. In addition, BMP2a and BMP5 play an inductive function in the expression of the cloche gene npas4l in PAA progenitors. cloche mutants exhibit a striking failure to specify PAA progenitors and display ectopic expression of head muscle markers in the pharyngeal mesoderm. Therefore, our results support a crucial role for pharyngeal pouches in establishing a progenitor niche for PAA morphogenesis via BMP2a/5 expression.

scholarly journals Pharyngeal pouches provide a niche microenvironment for arch artery progenitor specification

2020 ◽  
Author(s):  
Aihua Mao ◽  
Linwei Li ◽  
Jie Liu ◽  
Mingming Zhang ◽  
Guozhu Ning ◽  
...  
Keyword(s):  
Critical Role ◽  
Time Lapse ◽  
Pharyngeal Arch ◽  
Imaging Studies ◽  
Pharyngeal Pouch ◽  
Functional Interaction ◽  
Smad Pathway ◽  
Pharyngeal Arch Arteries ◽  
Time Lapse Imaging

AbstractThe paired pharyngeal arch arteries (PAAs) are transient blood vessels connecting the heart with the dorsal aorta during embryogenesis. Although PAA malformations often occur along with pharyngeal pouch defects, the functional interaction between these adjacent tissues remains largely unclear. Here we report that the ablation of pouches in zebrafish embryos impairs PAA progenitor specification and leads to the absence of PAA structures. Through time-lapse imaging studies, we reveal that the segmentation of pharyngeal pouches coincides spatiotemporally with the emergence of PAA progenitor clusters. These pouches physically associate with pharyngeal mesoderm in discrete regions and provide a niche microenvironment for PAA progenitor commitment by expressing BMP proteins. Specifically, tissue specific knockdown experiments demonstrate that pouch-derived BMP2a and BMP5 are the primary niche cues responsible for activating the BMP/Smad pathway in pharyngeal mesoderm, thereby promoting progenitor specification. In addition, BMP2a and BMP5 play a primary inductive function in the expression of the cloche gene npas4l in PAA progenitors. Mutation of the cloche locus represses the specification of PAA progenitors and generates ectopic muscle precursors in the pharyngeal mesoderm. Therefore, our results support a critical role of pharyngeal pouches in establishing a progenitor niche for PAA morphogenesis via BMP2a/5 expression.

A genetic link between Tbx1 and fibroblast growth factor signaling

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4605-4611 ◽  
Author(s):  
Francesca Vitelli ◽  
Ilaria Taddei ◽  
Masae Morishima ◽  
Erik N. Meyers ◽  
Elizabeth A. Lindsay ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Expression Patterns ◽  
Pharyngeal Arch ◽  
Growth Factor Signaling ◽  
Expression Domain ◽  
Primary Defect ◽  
Genetic Link ◽  
Pharyngeal Endoderm ◽  
Pharyngeal Arch Arteries ◽  
Tbx1 Haploinsufficiency

Tbx1 haploinsufficiency causes aortic arch abnormalities in mice because of early growth and remodeling defects of the fourth pharyngeal arch arteries. The function of Tbx1 in the development of these arteries is probably cell non-autonomous, as the gene is not expressed in structural components of the artery but in the surrounding pharyngeal endoderm. We hypothesized that Tbx1 may trigger signals from the pharyngeal endoderm directed to the underlying mesenchyme. We show that the expression patterns of Fgf8 and Fgf10, which partially overlap with Tbx1 expression pattern, are altered in Tbx1–/– mutants. In particular, Fgf8 expression is abolished in the pharyngeal endoderm. To understand the significance of this finding for the pathogenesis of the mutant Tbx1 phenotype, we crossed Tbx1 and Fgf8 mutants. Double heterozygous Tbx1+/–;Fgf8+/– mutants present with a significantly higher penetrance of aortic arch artery defects than do Tbx1+/–;Fgf8+/+ mutants, while Tbx1+/+;Fgf8+/– animals are normal. We found that Fgf8 mutation increases the severity of the primary defect caused by Tbx1 haploinsufficiency, i.e. early hypoplasia of the fourth pharyngeal arch arteries, consistent with the time and location of the shared expression domain of the two genes. Hence, Tbx1 and Fgf8 interact genetically in the development of the aortic arch. Our data provide the first evidence of a genetic link between Tbx1 and FGF signaling, and the first example of a modifier of the Tbx1 haploinsufficiency phenotype. We speculate that the FGF8 locus might affect the penetrance of cardiovascular defects in individuals with chromosome 22q11 deletions involving TBX1.

Gas Tensions in the Lungs and Major Blood Vessels of the Urodele Amphibian, Amphiuma Tridactylum

1971 ◽  
Vol 55 (1) ◽  
pp. 47-61
Author(s):  
DANIEL P. TOEWS ◽  
G. SHELTON ◽  
D. J. RANDALL
Keyword(s):  
Carbon Dioxide ◽  
Pulmonary Artery ◽  
Inferior Vena Cava ◽  
Blood Vessels ◽  
Pulmonary Vein ◽  
Oxygen Tension ◽  
Inferior Vena ◽  
Vena Cava ◽  
Dorsal Aorta ◽  
Oxygen Tensions

1. Oxygen and carbon dioxide tensions were determined in the lungs and in blood from the dorsal aorta, pulmonary vein, pulmonary artery and inferior vena cava in the intact, free swimming, Amphiuma. At 15° C this animal was submerged for a large part of the time and surfaced briefly to breathe at variable time intervals, the mean period being 45 min. 2. Oxygen tensions in the lungs and in all blood vessels oscillated with the breathing cycles, falling gradually during the period of submersion and rising rapidly after the animal breathed. The absolute level of oxygen tension did not appear to constitute the effective signal beginning or ending a series of breathing movements. 3. A small oxygen gradient existed between lungs and blood in the pulmonary vein immediately after a breath. The gradient increased in size as an animal remained submerged due, it is suggested, to lung vasoconstriction increasing the transfer factor. 4. Blood in the dorsal aorta had a lower oxygen tension than that in the pulmonary vein. A right-to-left shunt occurred as blood moved through the heart. The degree of shunting increased as the animal remained submerged and pulmonary vasoconstriction occurred. Left-to-right shunt was relatively insignificant since oxygen tensions in the inferior vena cava and pulmonary artery were very similar. 5. Carbon dioxide tensions were relatively constant during the breathing-diving cycle since Amphiuma removed almost all of this gas through the skin.

scholarly journals III. On the development of the arteries of the abdomen and their relation to the peritoneum

1885 ◽  
Vol 38 (235-238) ◽  
pp. 8-9 ◽  
Keyword(s):  
Blood Vessels ◽  
Dorsal Aorta

The paper begins by explaining that it records an endeavour to elucidate the course and relations of the abdominal blood-vessels upon developmental grounds. The earliest stages of the development of the midgut and its mesentery are first 'described; and it is shown that vessels extend at very frequent intervals from the dorsal aorta to the intestine, reaching the latter by way of the mesentery.

scholarly journals Molecular signature of an ancient organizer regulated by Wnt/β-catenin signalling during primary body axis patterning in Hydra

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Puli Chandramouli Reddy ◽  
Akhila Gungi ◽  
Suyog Ubhe ◽  
Saurabh J. Pradhan ◽  
Amol Kolte ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Regulatory Network ◽  
Critical Role ◽  
Ectopic Expression ◽  
Wnt Signalling ◽  
Body Axis ◽  
Molecular Signature ◽  
Zebrafish Embryos ◽  
Primary Body ◽  
Animal Phyla

AbstractWnt/β-catenin signalling has been shown to play a critical role during head organizer formation in Hydra. Here, we characterized the Wnt signalling regulatory network involved in formation of the head organizer. We found that Wnt signalling regulates genes that are important in tissue morphogenesis. We identified that majority of transcription factors (TFs) regulated by Wnt/β-catenin signalling belong to the homeodomain and forkhead families. Silencing of Margin, one of the Wnt regulated homeodomain TFs, results in loss of the ectopic tentacle phenotype typically seen upon activation of Wnt signalling. Furthermore, we show that the Margin promoter is directly bound and regulated by β-catenin. Ectopic expression of Margin in zebrafish embryos results in body axis abnormalities suggesting that Margin plays a role in axis patterning. Our findings suggest that homeobox TFs came under the regulatory umbrella of Wnt/β-catenin signalling presumably resulting in the evolution of primary body axis in animal phyla.

scholarly journals Cell - ECM Interactions Play Multiple Essential Roles in Aortic Arch Development

2020 ◽  
Author(s):  
Michael Warkala ◽  
Dongying Chen ◽  
AnnJosette Ramirez ◽  
Ali Jubran ◽  
Michael J Schonning ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Developmental Stages ◽  
Lineage Tracing ◽  
Confocal Imaging ◽  
Pharyngeal Arch ◽  
Cellular Mechanisms ◽  
Integrin Α5β1 ◽  
Pharyngeal Arches ◽  
Heart Field ◽  
Pharyngeal Arch Arteries

Rationale: Defects in the morphogenesis of the 4th pharyngeal arch arteries (PAAs) give rise to lethal birth defects. Understanding genes and mechanisms regulating PAA formation will provide important insights into the etiology and treatments for congenital heart disease. Objective: Cell-ECM interactions play essential roles in the morphogenesis of PAAs and their derivatives, the aortic arch artery (AAA) and its major branches; however, their specific functions are not well-understood. Previously, we demonstrated that integrin α5β1 and fibronectin (Fn1) expressed in the Isl1 lineages regulate PAA formation. The objective of the current studies was to investigate cellular mechanisms by which integrin α5β1 and Fn1 regulate AAA morphogenesis. Methods and Results: Using temporal lineage tracing, whole-mount confocal imaging, and quantitative analysis of the second heart field (SHF) and endothelial cell (EC) dynamics, we show that the majority of PAA EC progenitors arise by E7.5 in the SHF and contribute to pharyngeal arch endothelium between E7.5 and E9.5. Consequently, SHF-derived ECs in the pharyngeal arches form a uniform plexus of small blood vessels, which remodels into the PAAs by 35 somites. The remodeling of the vascular plexus is orchestrated by signals dependent on the pharyngeal ECM microenvironment, extrinsic to the endothelium. Conditional ablation of integrin α5β1 or Fn1 in the Isl1 lineages showed that signaling by the ECM regulates AAA morphogenesis at multiple steps: 1) accumulation of SHF-derived ECs in the pharyngeal arches, 2) remodeling of the uniform EC plexus in the 4th arches into the PAAs; and 3) differentiation of neural crest-derived cells adjacent to the PAA endothelium into vascular smooth muscle cells. Conclusions: PAA formation is a multi-step process entailing dynamic contribution of SHF-derived ECs to pharyngeal arches, the remodeling of endothelial plexus into the PAAs, and the remodeling of the PAAs into the AAA and its major branches. Cell-ECM interactions regulated by integrin α5β1 and Fn1 play essential roles at each of these developmental stages.

scholarly journals The presence of an embryonic opercular flap in amniotes

2011 ◽  
Vol 279 (1727) ◽  
pp. 224-229 ◽  
Author(s):  
Jo Richardson ◽  
Takanori Shono ◽  
Masataka Okabe ◽  
Anthony Graham
Keyword(s):  
Chick Embryo ◽  
Early Development ◽  
Bony Fish ◽  
Pharyngeal Arch ◽  
Zebrafish Embryos ◽  
Orthologous Genes ◽  
Amphibian Metamorphosis ◽  
Branchial Cleft Anomalies ◽  
Branchial Cleft

The operculum is a large flap consisting of several flat bones found on the side of the head of bony fish. During development, the opercular bones form within the second pharyngeal arch, which expands posteriorly and comes to cover the gill-bearing arches. With the evolution of the tetrapods and the assumption of a terrestrial lifestyle, it was believed that the operculum was lost. Here, we demonstrate that an embryonic operculum persists in amniotes and that its early development is homologous with that of teleosts. As in zebrafish, the second pharyngeal arch of the chick embryo grows disproportionately and comes to cover the posterior arches. We show that the developing second pharyngeal arch in both chick and zebrafish embryos express orthologous genes and require shh signalling for caudal expansion. In amniotes, however, the caudal edge of the expanded second arch fuses to the surface of the neck. We have detailed how this process occurs and also demonstrated a requirement for thyroid signalling here. Our results thus demonstrate the persistence of an embryonic opercular flap in amniotes, that its fusion mirrors aspects of amphibian metamorphosis and gives insights into the origin of branchial cleft anomalies in humans.

scholarly journals Cell – ECM interactions play distinct and essential roles at multiple stages during the development of the aortic arch

2020 ◽  
Author(s):  
Michael Warkala ◽  
Dongying Chen ◽  
Ali Jubran ◽  
AnnJosette Ramirez ◽  
Michael Schonning ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Developmental Stages ◽  
Lineage Tracing ◽  
Confocal Imaging ◽  
Pharyngeal Arch ◽  
Cellular Mechanisms ◽  
Integrin Α5β1 ◽  
Pharyngeal Arches ◽  
Heart Field ◽  
Pharyngeal Arch Arteries

RationaleDefects in the morphogenesis of the 4th pharyngeal arch arteries (PAAs) give rise to lethal birth defects. Understanding genes and mechanisms regulating PAA formation will provide important insights into the etiology and treatments for congenital heart disease.ObjectiveCell-ECM interactions play essential roles in the morphogenesis of PAAs and their derivatives, the aortic arch artery (AAA) and its major branches; however, their specific functions are not well-understood. Previously, we demonstrated that integrin α5β1 and fibronectin (Fn1) expressed in the Isl1 lineages regulate PAA formation. The objective of these studies was to investigate cellular mechanisms by which integrin α5β1 and Fn1 regulate AAA morphogenesis.Methods and ResultsUsing temporal lineage tracing, whole-mount confocal imaging, and quantitative analysis of the second heart field (SHF) and endothelial cell (EC) dynamics, we show that the majority of PAA EC progenitors arise by E7.5 in the SHF and populate pharyngeal arch mesenchyme between E7.5 and E9.5. Consequently, SHF-derived ECs in the pharyngeal arches become organized into a uniform plexus of small blood vessels, which becomes remodeled into the PAAs between 31 – 35 somites. The remodeling of the vascular plexus is orchestrated by signals dependent on pharyngeal ECM microenvironment extrinsic to the endothelium. Conditional ablation of integrin α5β1 or Fn1 in the Isl1 lineages showed that signaling by the ECM regulates AAA morphogenesis at multiple steps: 1) the recruitment of the SHF-derived ECs into the pharyngeal arches, 2) the remodeling of the uniform EC plexus in the 4th arches into the PAAs; and 3) differentiation of neural crest-derived cells abutting the PAA endothelium into vascular smooth muscle cells.ConclusionsPAA formation is a multi-step process entailing dynamic contribution of SHF-derived ECs to pharyngeal arches, the remodeling of endothelial plexus into the PAAs, and the remodeling of the PAAs into the AAA and its major branches. Cell-ECM interactions regulated by integrin α5β1 and Fn1 play essential roles at each of these developmental stages.

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