scholarly journals Dynamic BMP signaling polarized by Toll patterns the dorsoventral axis in a hemimetabolous insect

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Lena Sachs ◽  
Yen-Ta Chen ◽  
Axel Drechsler ◽  
Jeremy A Lynch ◽  
Kristen A Panfilio ◽  
...  
Keyword(s):  
Regulatory Networks ◽  
Bmp Signaling ◽  
Oncopeltus Fasciatus ◽  
Axis Formation ◽  
Dorsoventral Axis ◽  
Toll Signaling ◽  
Hemimetabolous Insect ◽  
Gene Regulatory ◽  
Insect Embryos ◽  
Regulatory Properties

Toll-dependent patterning of the dorsoventral axis in Drosophila represents one of the best understood gene regulatory networks. However, its evolutionary origin has remained elusive. Outside the insects Toll is not known for a patterning function, but rather for a role in pathogen defense. Here, we show that in the milkweed bug Oncopeltus fasciatus, whose lineage split from Drosophila's more than 350 million years ago, Toll is only required to polarize a dynamic BMP signaling network. A theoretical model reveals that this network has self-regulatory properties and that shallow Toll signaling gradients are sufficient to initiate axis formation. Such gradients can account for the experimentally observed twinning of insect embryos upon egg fragmentation and might have evolved from a state of uniform Toll activity associated with protecting insect eggs against pathogens.

scholarly journals Author response: Dynamic BMP signaling polarized by Toll patterns the dorsoventral axis in a hemimetabolous insect

2015 ◽  
Author(s):  
Lena Sachs ◽  
Yen-Ta Chen ◽  
Axel Drechsler ◽  
Jeremy A Lynch ◽  
Kristen A Panfilio ◽  
...  
Keyword(s):  
Bmp Signaling ◽  
Author Response ◽  
Dorsoventral Axis ◽  
Response Dynamic ◽  
Hemimetabolous Insect

scholarly journals Dissecting BMP signaling input into the gene regulatory networks driving specification of the blood stem cell lineage

2017 ◽  
Vol 114 (23) ◽  
pp. 5814-5821 ◽  
Author(s):  
Arif Kirmizitas ◽  
Stuart Meiklejohn ◽  
Aldo Ciau-Uitz ◽  
Rachel Stephenson ◽  
Roger Patient
Keyword(s):  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Cell Lineage ◽  
Bmp Signaling ◽  
Hematopoietic Stem ◽  
Bmp Receptors ◽  
Stem Cell Lineage ◽  
Morphogenetic Protein ◽  
Gene Regulatory ◽  
Endothelial Genes

Hematopoietic stem cells (HSCs) that sustain lifelong blood production are created during embryogenesis. They emerge from a specialized endothelial population, termed hemogenic endothelium (HE), located in the ventral wall of the dorsal aorta (DA). In Xenopus, we have been studying the gene regulatory networks (GRNs) required for the formation of HSCs, and critically found that the hemogenic potential is defined at an earlier time point when precursors to the DA express hematopoietic as well as endothelial genes, in the definitive hemangioblasts (DHs). The GRN for DH programming has been constructed and, here, we show that bone morphogenetic protein (BMP) signaling is essential for the initiation of this GRN. BMP2, -4, and -7 are the principal ligands expressed in the lineage forming the HE. To investigate the requirement and timing of all BMP signaling in HSC ontogeny, we have used a transgenic line, which inducibly expresses an inhibitor of BMP signaling, Noggin, as well as a chemical inhibitor of BMP receptors, DMH1, and described the inputs from BMP signaling into the DH GRN and the HE, as well as into primitive hematopoiesis. BMP signaling is required in at least three points in DH programming: first to initiate the DH GRN through gata2 expression, then for kdr expression to enable the DH to respond to vascular endothelial growth factor A (VEGFA) ligand from the somites, and finally for gata2 expression in the DA, but is dispensable for HE specification after hemangioblasts have been formed.

scholarly journals BMP Signaling: Lighting up the Way for Embryonic Dorsoventral Patterning

2021 ◽  
Vol 9 ◽  
Author(s):  
Yifang Yan ◽  
Qiang Wang
Keyword(s):  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Bmp Signaling ◽  
Axis Formation ◽  
Dorsoventral Patterning ◽  
Significant Events ◽  
Similarities And Differences ◽  
Signaling Components ◽  
Molecular Nature

One of the most significant events during early embryonic development is the establishment of a basic embryonic body plan, which is defined by anteroposterior, dorsoventral (DV), and left-right axes. It is well-known that the morphogen gradient created by BMP signaling activity is crucial for DV axis patterning across a diverse set of vertebrates. The regulation of BMP signaling during DV patterning has been strongly conserved across evolution. This is a remarkable regulatory and evolutionary feat, as the BMP gradient has been maintained despite the tremendous variation in embryonic size and shape across species. Interestingly, the embryonic DV axis exhibits robust stability, even in face of variations in BMP signaling. Multiple lines of genetic, molecular, and embryological evidence have suggested that numerous BMP signaling components and their attendant regulators act in concert to shape the developing DV axis. In this review, we summarize the current knowledge of the function and regulation of BMP signaling in DV patterning. Throughout, we focus specifically on popular model animals, such as Xenopus and zebrafish, highlighting the similarities and differences of the regulatory networks between species. We also review recent advances regarding the molecular nature of DV patterning, including the initiation of the DV axis, the formation of the BMP gradient, and the regulatory molecular mechanisms behind BMP signaling during the establishment of the DV axis. Collectively, this review will help clarify our current understanding of the molecular nature of DV axis formation.

scholarly journals The tolerance to hypoxia is defined by a time-sensitive response of the gene regulatory network in sea urchin embryos

Development ◽  
2021 ◽  
pp. dev.195859
Author(s):  
Majed Layous ◽  
Lama Khalaily ◽  
Tsvia Gildor ◽  
Smadar Ben-Tabou de-Leon
Keyword(s):  
Early Development ◽  
Sea Urchin ◽  
Regulatory Networks ◽  
Normal Development ◽  
Axis Formation ◽  
Oxygen Level ◽  
Sea Urchin Embryo ◽  
Tolerance To Hypoxia ◽  
Vegf Pathway ◽  
Gene Regulatory

Deoxygenation, the reduction of oxygen level in the oceans induced by global warming and anthropogenic disturbances, is a major threat to marine life. This change in oxygen level could be especially harmful to marine embryos that utilize endogenous hypoxia and redox gradients as morphogens during normal development. Here we show that the tolerance to hypoxic conditions changes between different developmental stages of the sea urchin embryo, possibly due to the structure of the gene regulatory networks (GRNs). We demonstrate that during normal development, bone morphogenetic protein (BMP) pathway restricts the activity of the vascular endothelial growth factor (VEGF) pathway to two lateral domains and by that controls proper skeletal patterning. Hypoxia applied during early development strongly perturbs the activity of Nodal and BMP pathways that affect VEGF pathway, dorsal-ventral (DV) and skeletogenic patterning. These pathways are largely unaffected by hypoxia applied after DV-axis formation. We propose that the use of redox and hypoxia as morphogens makes the sea urchin embryo highly sensitive to environmental hypoxia during early development, but the GRN structure provides higher tolerance to hypoxia at later stages.

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