... environment, highlighting their role in the regulation of normal and pathological bone development, homeostasis and repair. Osteoclast Bone development Hematopoietic stem cell Yolk sac National Institute on Aging http://dx.doi.org/10.13039/100000049 R01 AG072058 R01 AG049745...

... solution (Sigma-Aldrich) for 5 min into single cells. The single cell suspension was washed and re-suspended in PBS. Yolk sacs were dissected from equal numbers of mouse E9.5 and E10.5 embryos, mixed together and dissociated with 0.25% collagenase at 37°C for 30 min. The cells were stored at −80°C...

... are microglia, suggesting that defective Hoxb8 microglia caused the disorder. What is the source of the Hoxb8 microglia? It has been posited that all microglia progenitors arise at embryonic day (E) 7.5 during yolk sac hematopoiesis, and colonize the brain at E9.5. In contrast, we show the presence of two...

... transcription. Although the factors regulating EHT in hemogenic endothelium (HE) of the dorsal aorta have been relatively well studied, the molecular regulation of yolk sac HE remains poorly understood. Here, we show that SOX7 inhibits the expression of RUNX1 target genes in HE, while having no effect on RUNX1...

... ( mdickins@bcm.tmc.edu ) Competing interests statement The authors declare no competing financial interests. 17 7 2013 © 2013. Published by The Company of Biologists Ltd 2013 Cell migration Endothelial cell Mouse Vascular remodeling Vessel fusion Yolk sac...

... key issues currently circulating in this field. * Author for correspondence ( a.medvinsky@ed.ac.uk ) Competing interests statement The authors declare no competing financial interests. © 2011. 2011 AGM region Yolk sac Placenta dHSC Pre-dHSC The ontogeny...

... populations that can be isolated based on temporal patterns of emergence. The earliest arising population displays characteristics of yolk sac hematopoiesis, whereas a late developing Flk1-positive population appears to reflect the para-aortic splanchnopleura hematopoietic program, as it has reduced primitive...

.... Remarkably, microsurgical perturbation of the wild-type allantoic core phenocopied the T C /T C vascularization defect, providing further support that an intact core is essential for vascularization. Last, abnormalities were observed in the T C /T C heart and yolk sac, recently reported sites of T...

... in stromal co-cultures arose as early as E8.5, i.e. prior to establishment of the circulation within the paraaortic splanchnopleura (P-Sp). These cells were Tie2 + RAG1 - CD34 Lo/- Kit + CD41 - . While yolk sac (YS) also contained lymphopoietic cells after E9.5, CD41 + YS cells from ⩽25-somite embryos...

...Samir Taoudi; Aline M. Morrison; Hirofumi Inoue; Ruby Gribi; Janice Ure; Alexander Medvinsky The yolk sac and the para-aortic splanchnopleura/aorta-genital ridges-mesonephros (P-Sp/AGM) region are the main sites of haematopoietic activity in the mouse embryo at the pre-liver stage of development...

...Robert Spoelgen; Annette Hammes; Uwe Anzenberger; Dietmar Zechner; Olav M. Andersen; Boris Jerchow; Thomas E. Willnow Megalin is a low-density lipoprotein receptor-related protein (LRP2)expressed in the neuroepithelium and the yolk sac of the early embryo. Absence of megalin expression in knockout...

... or activin receptor like kinase (ALK) 1 die at mid-gestation as a result of defects in the yolk sac vasculature. Here, we have analyzed TGFβsignalling in yolk sacs from endoglin knockout mice and from mice with endothelial-specific deletion of the TGFβ type II receptor (TβRII)or ALK5. We show that TGFβ/ALK5...

... postimplantation development. Therefore, in this study, we explored the effects of NO during vascular development of the murine yolk sac, which begins shortly after implantation. Establishment of the vitelline circulation is crucial for normal embryonic growth and development. Moreover, functional inactivation...

..., we generated a Hand1 knockout mouse. Hand1 -null mice survived to the nine somite stage at which time they succumbed to numerous developmental defects. One striking defect in Hand1 -null embryos was the accumulation of hematopoietic cells between the yolk sac and the amnion because of defects...

... to study the role of this gene during development and disease, we produced a mutation in the mouse ortholog, Tbx3 . The phenotype of the mutant mice verifies the role of this gene in limb and mammary gland development, and, in addition, reveals a previously unknown role for the gene in the yolk sac...

... of the aorta-gonadmesonephros (AGM) region and the yolk sac to produce/expand definitive HSC/RUs during days 11-12 of embryogenesis. We show that the capacity of the AGM region to generate definitive HSC/RUs is high on 11 d.p.c. but significantly reduced by 12 d.p.c. Conversely, at 12 d.p.c. the YS acquires...

...Estelle Oberlin; Manuela Tavian; Istvàn Blazsek; Bruno Péault Hematopoietic cells arise first in the third week of human ontogeny inside yolk sac developing blood vessels, then, one week later and independently, from the wall of the embryonic aorta and vitelline artery. To address the suggested...

...Noah Byrd; Sandy Becker; Peter Maye; Roopa Narasimhaiah; Benoit St-Jacques; Xiaoyan Zhang; Jill McMahon; Andrew McMahon; Laura Grabel Blood islands, the precursors of yolk sac blood vessels, contain primitive erythrocytes surrounded by a layer of endothelial cells. These structures differentiate...

... in yolk sac or allantois; chorioallantoic fusion fails; the amnion does not expand with the growth of the embryo, but misexpresses vascular and hematopoietic markers. Separation of the bulk of yolk sac mesoderm from the endodermal layer and adherence between mesoderm of yolk sac and amnion, indicate...

... , genes known to be involved in the development and maturation of the hematopoietic system. Kinetic analysis revealed the transient nature of the primitive erythroid lineage, as progenitors increased in number in the developing yolk sac until early somite-pair stages of development (E8.25...