scholarly journals Patterning of the vertebrate head in time and space by BMP signalling

2019 ◽  
Author(s):  
Kongju Zhu ◽  
Herman P. Spaink ◽  
Antony J. Durston
Keyword(s):  
Gene Sequence ◽  
Cement Gland ◽  
Time And Space ◽  
Frog Embryo ◽  
Head Development ◽  
Bmp Signalling

AbstractHow head patterning is regulated in vertebrates is yet to be understood. In this study, we show that frog embryos injected with Noggin at different blastula and gastrula stages had their head development sequentially arrested at different positions. When timed BMP inhibition was applied to BMP-overexpressing embryos, the expression of five genes: xcg-1 (a marker of the cement gland, which is the front-most structure in the frog embryo), six3 (a forebrain marker), otx2 (a forebrain and mid-brain marker), gbx2 (an anterior hindbrain marker) and hoxd1 (a posterior hindbrain marker) were sequentially fixed. These results suggest that timed interactions between BMP and anti-BMP are involved in patterning the vertebrate head progressively in time and space. Since the above genes are not expressed sequentially, there may be a BMP dependent gene sequence during head patterning that can be arrested by BMP inhibition and regulate the specification of positional values in the head.

scholarly journals Initiating head development in mouse embryos: integrating signalling and transcriptional activity

Open Biology ◽  
2012 ◽  
Vol 2 (3) ◽  
pp. 120030 ◽  
Author(s):  
Ruth M. Arkell ◽  
Patrick P. L. Tam
Keyword(s):  
Mouse Embryo ◽  
Common Property ◽  
Body Plan ◽  
Head Development ◽  
Stage Of Development ◽  
Morphogenetic Protein ◽  
Signalling Cascades ◽  
Intercellular Signalling ◽  
Bmp Signalling ◽  
Embryonic Head

The generation of an embryonic body plan is the outcome of inductive interactions between the progenitor tissues that underpin their specification, regionalization and morphogenesis. The intercellular signalling activity driving these processes is deployed in a time- and site-specific manner, and the signal strength must be precisely controlled. Receptor and ligand functions are modulated by secreted antagonists to impose a dynamic pattern of globally controlled and locally graded signals onto the tissues of early post-implantation mouse embryo. In response to the WNT, Nodal and Bone Morphogenetic Protein (BMP) signalling cascades, the embryo acquires its body plan, which manifests as differences in the developmental fate of cells located at different positions in the anterior–posterior body axis. The initial formation of the anterior (head) structures in the mouse embryo is critically dependent on the morphogenetic activity emanating from two signalling centres that are juxtaposed with the progenitor tissues of the head. A common property of these centres is that they are the source of antagonistic factors and the hub of transcriptional activities that negatively modulate the function of WNT, Nodal and BMP signalling cascades. These events generate the scaffold of the embryonic head by the early-somite stage of development. Beyond this, additional tissue interactions continue to support the growth, regionalization, differentiation and morphogenesis required for the elaboration of the structure recognizable as the embryonic head.

Taking time and space out of service delivery

2000 ◽  
Author(s):  
Lisa Rabasca
Keyword(s):  
Service Delivery ◽  
Time And Space

Time and space in episodic memory

2012 ◽  
Author(s):  
Christoph Hoerl
Keyword(s):  
Episodic Memory ◽  
Time And Space

Across the globe: Mental health in time and space

2009 ◽  
Author(s):  
Karen Nakamura
Keyword(s):  
Mental Health ◽  
Time And Space

Economy as an Organism

2011 ◽  
pp. 140-151
Author(s):  
A. Golubev
Keyword(s):  
Time And Space

Practicability of viewing economy not as a mechanism but as an organism is grounded. The concept of "genetic economics" that is considered in time and space is defined. The orders of economic constancy are recommended. "Genetic economics" axiomatic statements are formularized.

Fictive Mode, ‘Journey to the West’, and Transformation of Space: ‘Ali Mubarak’s Discourses of Modernization

2007 ◽  
Vol 4 (3) ◽  
pp. 331-358
Author(s):  
WEN-CHIN OUYANG
Keyword(s):  
Cultural Transformation ◽  
Recent History ◽  
Theoretical Principle ◽  
Time And Space ◽  
The West ◽  
Arab Culture ◽  
History Of ◽  
Journey To The West

I begin my exploration of ‘Ali Mubarak (1823/4–1893) and the discourses on modernization ‘performed’ in his only attempt at fiction, ‘Alam al-Din (The Sign of Religion, 1882), with a quote from Guy Davenport because it elegantly sums up a key theoretical principle underpinning any discussion of cultural transformation and, more particularly, of modernization. Locating ‘Ali Mubarak and his only fictional work at the juncture of the transformation from the ‘traditional’ to the ‘modern’ in the recent history of Arab culture and of Arabic narrative, I find Davenport's pronouncement tantalizingly appropriate. He not only places the stakes of history and geography in one another, but simultaneously opens up the imagination to the combined forces of time and space that stand behind these two distinct yet related disciplines.

Afterword: Health, Care, Citizens

2018 ◽  
Author(s):  
Stuart Murray
Keyword(s):  
Health Care ◽  
Interpersonal Relationships ◽  
Health It ◽  
Time And Space ◽  
And Control

Care’ is a shifting, plural word when used in the context of discussions of health. It suggests attention and compassion when articulated as a verb, but has overtures of regulation and control when used as a noun – to be ‘in care’ is usually not unproblematic. Two chapters in this section – those by Sarah Atkinson and Lucy Burke – speak specifically to the complexities of this idea. As Atkinson makes clear in her chapter, care invokes questions of resource just as much as it outlines interpersonal relationships; it presents what she terms ‘dilemmas, paradoxes and challenges’ when conceived of as a totality and, especially in global contexts, suggests entangled modes of time and space.

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