Visualizing the Vascular Network in the Mouse Embryo and Yolk Sac

2018 ◽  
pp. 11-16 ◽  
Author(s):  
Anna R. Roy ◽  
Paul Delgado-Olguin
Keyword(s):  
Mouse Embryo ◽  
Yolk Sac ◽  
Vascular Network

scholarly journals Initiation of hematopoiesis and vasculogenesis in murine yolk sac explants

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 156-163 ◽  
Author(s):  
J Palis ◽  
KE McGrath ◽  
PD Kingsley
Keyword(s):  
Endothelial Cells ◽  
Network Formation ◽  
Globin Gene ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Vascular Network ◽  
Globin Mrna ◽  
Capillary Networks ◽  
Stage Of Development ◽  
Extraembryonic Mesoderm

The blood islands of the visceral yolk sac (VYS) are the initial sites of hematopoiesis in mammals. We have developed a yolk sac explant culture system to study the process of blood cell and endothelial cell development from extraembryonic mesoderm cells. No benzidine-positive cells or beta H1-globin mRNA expression was detected at the primitive streak or neural plate stage of development (E7.5). However, when isolated E7.5 dissected tissues were cultured for 36 to 72 hours in serum-free medium, hundreds of hemoglobin-producing cells and embryonic globin gene expression were identified in both intact yolk sac and VYS mesoderm explants. Explanted E7.5 extraembryonic mesoderm tissues thus recapitulate in vivo primitive erythropoiesis and do not require the presence of a vascular network or the VYS endoderm. Yolk sac blood islands also contain endothelial cells that arise by vasculogenesis and express flk-1. We detected flk-1 mRNA as early as the primitive streak stage of mouse embryogenesis. Culture of embryo proper and intact VYS explants, which contain both mesoderm and endoderm cells, produced capillary networks and expressed flk-1. In contrast, vascular networks were not seen when VYS mesoderm was cultured alone, although flk-1 expression was similar to that of intact VYS explants. The addition of vascular endothelial growth factor to VYS mesoderm explants did not induce vascular network formation. These results suggest that the VYS endoderm or its extracellular matrix is necessary for the coalescence of developing endothelial cells into capillary networks.

Expression of CD41 marks the initiation of definitive hematopoiesis in the mouse embryo

Blood ◽  
2003 ◽  
Vol 101 (2) ◽  
pp. 508-516 ◽  
Author(s):  
Hanna K. A. Mikkola ◽  
Yuko Fujiwara ◽  
Thorsten M. Schlaeger ◽  
David Traver ◽  
Stuart H. Orkin
Keyword(s):  
Endothelial Cells ◽  
Mouse Embryo ◽  
Fetal Liver ◽  
Stem Cell Differentiation ◽  
Yolk Sac ◽  
Embryoid Bodies ◽  
Embryonic Stem Cell Differentiation ◽  
Hematopoietic Progenitors ◽  
Hematopoietic Stem ◽  
Definitive Hematopoiesis

Murine hematopoietic stem cells (HSCs) originate from mesoderm in a process that requires the transcription factor SCL/Tal1. To define steps in the commitment to blood cell fate, we compared wild-type and SCL−/− embryonic stem cell differentiation in vitro and identified CD41 (GpIIb) as the earliest surface marker missing from SCL−/− embryoid bodies (EBs). Culture of fluorescence-activated cell sorter (FACS) purified cells from EBs showed that definitive hematopoietic progenitors were highly enriched in the CD41+ fraction, whereas endothelial cells developed from CD41− cells. In the mouse embryo, expression of CD41 was detected in yolk sac blood islands and in fetal liver. In yolk sac and EBs, the panhematopoietic marker CD45 appeared in a subpopulation of CD41+ cells. However, multilineage hematopoietic colonies developed not only from CD45+CD41+ cells but also from CD45−CD41+ cells, suggesting that CD41 rather than CD45 marks the definitive culture colony-forming unit (CFU-C) at the embryonic stage. In contrast, fetal liver CFU-C was CD45+, and only a subfraction expressed CD41, demonstrating down-regulation of CD41 by the fetal liver stage. In yolk sac and EBs, CD41 was coexpressed with embryonic HSC markers c-kit and CD34. Sorting for CD41 and c-kit expression resulted in enrichment of definitive hematopoietic progenitors. Furthermore, the CD41+c-kit+ population was missing from runx1/AML1−/− EBs that lack definitive hematopoiesis. These results suggest that the expression of CD41, a candidate target gene of SCL/Tal1, and c-kit define the divergence of definitive hematopoiesis from endothelial cells during development. Although CD41 is commonly referred to as megakaryocyte–platelet integrin in adult hematopoiesis, these results implicate a wider role for CD41 during murine ontogeny.

scholarly journals A Karyometrical Study of Circulating Erythroblasts of Yolk Sac Origin in the Mouse Embryo

1986 ◽  
Vol 49 (5) ◽  
pp. 535-541 ◽  
Author(s):  
Kazunobu SASAKI ◽  
George MATSUMURA
Keyword(s):  
Mouse Embryo ◽  
Yolk Sac

Vascularization in the murine allantois occurs by vasculogenesis without accompanying erythropoiesis

Development ◽  
1998 ◽  
Vol 125 (22) ◽  
pp. 4507-4520 ◽  
Author(s):  
K.M. Downs ◽  
S. Gifford ◽  
M. Blahnik ◽  
R.L. Gardner
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
Cell Lineage ◽  
Immunohistochemical Analysis ◽  
Distal Region ◽  
Yolk Sac ◽  
Neural Plate ◽  
Vascular Network ◽  
Erythroid Cells ◽  
Erythroid Precursor

The aim of this study was to determine whether the blood vessels of the murine allantois are formed by vasculogenesis or angiogenesis. Morphological analysis revealed that differentiation of allantoic mesoderm into an outer layer of mesothelium and an inner vascular network begins in the distal region of the allantois, which is most remote from other tissues, as early as the late neural plate stage (approximately 7.75 days postcoitum). Nascent blood vessels were not found in the base of the allantois until 4-somite pairs had formed in the fetus (approximately 8.25 days postcoitum), and vascular continuity with the yolk sac and fetus was not present until the 6-somite-pair stage (approximately 8.5 days postcoitum). Immunohistochemical analysis demonstrated that flk-1, a molecular marker of early endothelial cells, is expressed in significantly more distal than basal core cells in the early allantois and never in mesothelium. Furthermore, synchronous grafting of donor yolk sac containing blood islands into blood islands of headfold-stage host conceptuses provided no evidence that the yolk sac contributes endothelial cells to the allantois. Finally, when removed from conceptuses and cultured in isolation, neural plate and headfold-stage allantoises formed a conspicuous vascular network that was positive for Flk-1. Hence, the vasculature of the allantois is formed intrinsically by vasculogenesis rather than extrinsically via angiogenesis from the adjacent yolk sac or fetus. Whether allantoic vasculogenesis is associated with erythropoiesis was also investigated. Benzidine-staining in situ revealed that primitive erythroid cells were not identified in the allantois until 6-somite pairs when continuity between its vasculature and that of the yolk sac was first evident. Nevertheless, a small number of allantoises removed from conceptuses at a considerably earlier stage were found to contain erythroid precursor cells following culture in isolation. To determine whether such erythroid cells could be of allantoic origin, host allantoises were made chimeric with lacZ-expressing donor allantoises that were additionally labeled with [3H]methyl thymidine. Following culture and autoradiography, many lacZ-expressing benzidine-stained cells were observed in donor allantoises, but none contained silver grains above background. Moreover, no cells of donor allantoic origin were found in the fetus or yolk sac. Hence, vasculogenesis seems to be independent of erythropoiesis in the allantois and to involve a distal-to-proximal gradient in differentiation of allantoic mesoderm into the endothelial cell lineage. Furthermore, this gradient is established earlier than reported previously, being present at the neural plate stage.

Genome Expression Profiling of the First Hematopoietic Progenitors of the Mouse Embryo.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2536-2536
Author(s):  
Margaret H. Baron ◽  
Joan Isern ◽  
Stuart T. Fraser ◽  
Zhiyong He ◽  
David Tuck ◽  
...  
Keyword(s):  
Mouse Embryo ◽  
Expression Profiling ◽  
Yolk Sac ◽  
Transcriptional Networks ◽  
Cell Type ◽  
Hematopoietic Progenitors ◽  
Genome Expression ◽  
Stage Of Development ◽  
Gfp Reporter ◽  
Major Cluster

Abstract Abstract 2536 Poster Board II-513 The transcriptional networks that regulate lineage commitment and expansion of the earliest hematopoietic progenitors in the mammalian embryo have not been well studied, due to a lack of methods for isolating these cells. We have begun to address this problem by purifying the first hematopoietic-committed progenitors in the mouse embryo based on expression of a human ε-globin::H2B-EGFP transgene that is expressed exclusively within the primitive erythroid (EryP) lineage, as early as embryonic day (E) 7.5. EryP are the first lineage-specific cell type to form in the embryo. They arise in large numbers from yolk sac-derived progenitors at the end of gastrulation, enter the circulation as nucleated cells soon thereafter, and continue to mature in a stepwise, synchronous fashion until they enucleate. The early and lineage specific expression of the GFP reporter allowed us to isolate not only circulating EryP (E9.5-E11.5) but also a population from dispersed E7.5-8.5 embryos that is enriched in EryP progenitors. Genome expression profiling allowed us to define the transcriptome from each stage of development and revealed highly dynamic changes during the progression from progenitor to maturing erythroblast. Hierarchical clustering analysis was used to organize genes on the basis of overall similarity in expression patterns; six major cluster patterns were identified. Genes within these clusters comprised distinct functional classes. For example, particularly prominent increases in expression were detected for genes involved in ribosome biogenesis, translation, chromosome condensation, and autophagy. Genes that were downregulated included those involved in DNA replication, cell cycle, and nucleolar and organelle biogenesis. We have focused on the emergence of EryP in the yolk sac. Expression of Gata2 is high in the progenitor population at E7.5 and decreases dramatically by E8.5. In contrast, Gata1, Scl, and Eklf are all upregulated during maturation of EryP progenitors, suggesting that these transcription factors have distinct functions during primitive erythropoiesis. Consistent with expression of the GFP reporter as early as E7.5, we find that endogenous mouse embryonic globin genes are also expressed at this stage. Therefore, globin gene expression is an early feature of EryP development. Analysis of promoters of differentially expressed genes allowed us to identify candidate transcriptional regulators, some of which have not previously been implicated in erythroid development. This is the first lineage specific transcription profiling of a differentiating hematopoietic cell type in the early mouse embryo. While we have focused on the development of EryP, insights from this study should have broader relevance to the definitive erythroid lineage. Disclosures: No relevant conflicts of interest to declare.

The orderly allocation of mesodermal cells to the extraembryonic structures and the anteroposterior axis during gastrulation of the mouse embryo

Development ◽  
1999 ◽  
Vol 126 (21) ◽  
pp. 4691-4701 ◽  
Author(s):  
S.J. Kinder ◽  
T.E. Tsang ◽  
G.A. Quinlan ◽  
A.K. Hadjantonakis ◽  
A. Nagy ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Mouse Embryo ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Cell Lineages ◽  
Anteroposterior Axis ◽  
Extraembryonic Mesoderm ◽  
Extraembryonic Membranes ◽  
Lateral Mesoderm ◽  
Late Stages

The prospective fate of cells in the primitive streak was examined at early, mid and late stages of mouse gastrula development to determine the order of allocation of primitive streak cells to the mesoderm of the extraembryonic membranes and to the fetal tissues. At the early-streak stage, primitive streak cells contribute predominantly to tissues of the extraembryonic mesoderm as previously found. However, a surprising observation is that the erythropoietic precursors of the yolk sac emerge earlier than the bulk of the vitelline endothelium, which is formed continuously throughout gastrula development. This may suggest that the erythropoietic and the endothelial cell lineages may arise independently of one another. Furthermore, the extraembryonic mesoderm that is localized to the anterior and chorionic side of the yolk sac is recruited ahead of that destined for the posterior and amnionic side. For the mesodermal derivatives in the embryo, those destined for the rostral structures such as heart and forebrain mesoderm ingress through the primitive streak early during a narrow window of development. They are then followed by those for the rest of the cranial mesoderm and lastly the paraxial and lateral mesoderm of the trunk. Results of this study, which represent snapshots of the types of precursor cells in the primitive streak, have provided a better delineation of the timing of allocation of the various mesodermal lineages to specific compartments in the extraembryonic membranes and different locations in the embryonic anteroposterior axis.

Visualizing the spatiotemporal pattern of yolk sac membrane vascular network by enhanced local fractal analysis

2021 ◽  
Author(s):  
Peilun Li ◽  
Qing Pan ◽  
Sheng Jiang ◽  
Wolfgang M. Kuebler ◽  
Axel R. Pries ◽  
...  
Keyword(s):  
Fractal Analysis ◽  
Yolk Sac ◽  
Vascular Network ◽  
Spatiotemporal Pattern
Sign in / Sign up

Export Citation Format

Share Document