scholarly journals Patterning mechanisms in the body trunk and the appendages of Drosophila

Development ◽  
1999 ◽  
Vol 126 (13) ◽  
pp. 2823-2828 ◽  
Author(s):  
G. Morata ◽  
E. Sanchez-Herrero
Keyword(s):  
Pattern Formation ◽  
Body Wall ◽  
Hox Genes ◽  
The Body ◽  
Gene Products ◽  
Animal Groups ◽  
Signalling Molecules

During evolution, many animal groups have developed specialised outgrowths of the body wall, limbs or appendages. The type of appendage depends on the identity of the segment where they appear, indicating that the Hox genes contribute to appendage specification. Moreover, work carried out principally in Drosophila has identified the gene products and the mechanisms involved in pattern formation in the appendages. In this essay, we compare the morphogenetic processes in the appendages and the body wall; the function of the Hox genes and the response to the signalling molecules involved in local patterning. We speculate that, although the basic mechanisms are similar, there are significant differences in the manner the body trunk and appendages respond to them.

The effect of removing posterior apical ectodermal ridge of the chick wing and leg on pattern formation

Development ◽  
1981 ◽  
Vol 65 (Supplement) ◽  
pp. 309-325
Author(s):  
Donene A. Rowe ◽  
John F. Fallon
Keyword(s):  
Pattern Formation ◽  
Body Wall ◽  
Alternative Interpretation ◽  
Apical Ectodermal Ridge ◽  
The Body ◽  
Fate Map ◽  
Wing Bud ◽  
Rule Out

Recent experiments, in which barriers were inserted between anterior and posterior tissues of the chick wing bud, resulted in deletion of structures anterior to the barrier (Summerbell, 1979). From these data it was concluded that blockage of morphogen from the polarizing zone by the barrier resulted in the observed failure of specification of anterior structures. We suggest an alternative interpretation, viz. the interruption of the apical ridge by the barrier caused the deletions. This hypothesis was tested by removal of increasing lengths of ridge. This was done beginning at either the anterior or posterior junction of the wing bud with the body wall and proceeding posteriorly or anteriorly, respectively, to each half-somite level between 16/17 and 19/20. With removal of progressively greater lengths of anterior ridge, more anterior limb elements failed to develop. These data were used to construct a map of the ridge responsible for each digit. To test our hypothesis we removed posterior sections of apical ridge, as described above. Removal of posterior ridge to a level which was expected to allow outgrowth of digits anterior to the level of removal resulted in wings without digits in the majority of cases. An exception occurred when ridge posterior to the mid-19 somite level was removed. In almost half of these cases digits 2 and 3 did develop. In most cases the retention of only a half-somite piece of ridge with all other ridge removed, also resulted in deletion of all digits. Again the exception occurred when ridge posterior to somite level mid-19 and anterior to level 18/19 was removed, leaving only that ridge between somite level 18/19 and mid-19. In many of these cases digit 3 did develop. We conclude from these data that, in the wing bud, ridge anterior to the mid-19 somite level must be connected to more posterior ridge to function. The leg ridge does not exhibit the asymmetrical, low anterior, high posterior configuration, which appears in the wing. Because the leg ridge is symmetrically high anteriorly and posteriorly, we questioned whether or not leg would also require a continuity between anterior and posterior ridge for anterior ridge to function. It did not. When posterior ridge was removed, structures developed under remaining anterior ridge and the elements which developed were complementary to those which developed after anterior ridge removal to the same somite level. Those leg elements, which failed to develop, were truncated at the appropriate proximodistal levels as indicated by the fate map we have constructed for the leg. The data reported here do not rule out a role for the polarizing zone in specification of anterior structures. It is apparent that posterior ridge removal in the wing results in loss of structures anterior to the removal. However, this is not true for the leg.

Evolutionary Waves: Patterns in the Origins of Animal Phyla.

1985 ◽  
Vol 33 (2) ◽  
pp. 153 ◽  
Author(s):  
WG Inglis
Keyword(s):  
Body Wall ◽  
Functional Anatomy ◽  
Distinct Group ◽  
Body Cavity ◽  
The Body ◽  
Animal Groups ◽  
Structural Modifications ◽  
Hydrostatic Skeleton ◽  
Animal Phyla ◽  
Common Ancestors

Concordant patterns of embryology, morphology and functional anatomy delimit grades of animal phyla, each of which contains a 'Major Phylum': PARACOELOMATA (nom.nov.) = acoelomates + pseudocoelomates, flexible hydrostatic skeleton, Nematoda; DEUTEROSTOMIA (including lophophorates) = enterocoelic coelom, rigid internal skeleton, Chordata; and PROTOSTOMIA with two subgrades, MONOMERIC P. = unsegmented, single coelom, molluscan blastular cross, partial rigid exoskeleton, Molluscs; and POLYMERIC P. = segmented, multiple coelom, annelid cross, rigid exoskeleton, Uniramia. Such groups are usually treated as arbitrary stages in mono- and limited-branch phylogenies, but recent studies show them to be real and significant because the only phylogenetic links are from each Paracoelomata and Protostomia Phylum to Turbellaria; and each Deuterostomia Phylum to Cnidaria-Ctenophora and/or enteropneust Hemichordata. Similar grades have often been explained by hypothetical common ancestors, which are unnecessary if the phyla arose during 'evolutionary waves'. These attribute the origin of each grade to the likelihood that its constituent phyla arose independently, about the same time, from the same ciliary powered ancestral stock which was preadapted to enabling a potential body cavity to be actualized while evolving a cylindrical, wholly muscle-powered, body with a hydrostatic skeleton. Because such a skeleton is functionally dependent upon other structural modifications, particularly of the body wall, it could appear only when these were also available. If the latter could be supplied in a number of ways, all opportunities would be exploited and a body cavity would appear several times. The morphology suggests that this did happen, so that a pseudocoelom and coelom evolved independently in each phylum where they occur. Because of evidence that Protostomia and Deuterostomia were never linked during evolution, the origin of the coeloms in the former are explained by the Gonocoelic Theory and in the latter by the Enterocoelic. This, with the recognition of the monomeric protostomes as a distinct group, establishes that segmentation arose at the same time as the coeloms, so that their origins are one problem and not two as usually thought. Finally, protistan data suggest that Turbellaria, and so Paracoelomata and Protostomia, arose from 'close mitosis' flagellates, as did Fungi; while Cnidaria, and so Deuterostomia, arose from 'open mitosis' flagellates. as did Plantae. Thus, the classic Animalia division into Protostomia and Deuterostomia may represent a Protista division such that the animal groups are closer to fungi and plants respectively than they are to each other.

Lymphangiomatosis of the Body Wall: A Report of Two Cases Associated with Chylothorax and Fatal Outcome

1997 ◽  
Vol 17 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Philippe Moerman ◽  
Chris Van Geet ◽  
Hugo Devlieger
Keyword(s):  
Body Wall ◽  
Fatal Outcome ◽  
The Body

Harnessing clay nano-particles for stem-cell driven tissue regeneration, EPSRC

Impact ◽  
2018 ◽  
Vol 2018 (3) ◽  
pp. 26-28
Author(s):  
Jonathan Dawson ◽  
Richard Oreffo
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Blood Vessels ◽  
The Body ◽  
Biological Molecules ◽  
Nano Particles ◽  
Clay Particles ◽  
Clay Nanoparticles ◽  
Signalling Molecules ◽  
The Right

Gels made from clay could provide an environment able to stimulate stem-cells due to their ability to bind biological molecules. That molecules stick to clay has been known by scientists since the 1960s. Doctors observed that absorption into the blood stream of certain drugs was severely reduced when patients were also receiving clay-based antacid or anti-diarrhoeal treatments. This curious phenomenon was realized to be due to binding of the drugs by clay particles. This interaction is now routinely harnessed in the design of tablets to carefully control the release and action of a drug. Dr Dawson now proposes to use this property of clay to create micro-environments that could stimulate stem cells to regenerate damaged tissues such as bone, cartilage or skin. The rich electrostatic properties of nano (1 millionth of a millimetre) -scale clay particles which mediate these interactions could allow two hurdles facing the development of stem-cell based regenerative therapies to be overcome simultaneously. The first challenge - to deliver and hold stem cells at the right location in the body - is met by the ability of clays to self-organise into gels via the electrostatic interactions of the particles with each other. Cells mixed with a low concentration (less than 4%) of clay particles can be injected into the body and held in the right place by the gel, eliminating, in many situations, the need for surgery. Clay particles can also interact with large structural molecules (polymers) which are frequently used in the development of materials (or 'scaffolds'), designed to host stem cells. These interactions can greatly improve the strength of such structures and could be applied to preserve their stability at the site of injury until regeneration is complete. While several gels and scaffold materials have been designed to deliver and hold stem cells at the site of regeneration, the ability of clay nanoparticles to overcome a second critical hurdle facing stem-cell therapy is what makes them especially exciting. Essential to directing the activity of stem-cells is the carefully controlled provision of key biological signalling molecules. However, the open structures of conventional scaffolds or gels, while essential for the diffusion of nutrients to the cells, means their ability to hold the signalling molecules in the same location as the cells is limited. The ability of clay nano-particles to bind biological molecules presents a unique opportunity to create local environments at a site of injury or disease that can stimulate and control stem-cell driven repair. Dr Dawson's early studies investigated the ability of clay gels to stimulate the growth of new blood vessels by incorporating a key molecular signal that stimulates this process, vascular endothelial growth factor (VEGF). In a manner reminiscent of the observations made in the 60s, Dr Dawson and colleagues observed that adding a drop of clay gel to a solution containing VEGF caused, after a few hours, the disappearance of VEGF from the solution as it became bound to the gel. When placed in an experimental injury model, the gel-bound VEGF stimulated a cluster of new blood vessels to form. These exciting results indicate the potential of clay nanoparticles to create tailor-made micro-environments to foster stem cell regeneration. Dr Dawson is developing this approach as a means of first exploring the biological signals necessary to successfully control stem cell behaviour for regeneration and then, using the same approach, to provide stem cells with these signals to stimulate regeneration in the body. The project will seek to test this approach to regenerate bone lost to cancer or hip replacement failure. If successful the same technology may be applied to harness stem cells for the treatment of a whole host of different scenarios, from burn victims to those suffering with diabetes or Parkinson's.

scholarly journals A screen for genetic loci required for body-wall muscle development during embryogenesis in Caenorhabditis elegans.

Genetics ◽  
1994 ◽  
Vol 137 (2) ◽  
pp. 483-498
Author(s):  
J Ahnn ◽  
A Fire
Keyword(s):  
Caenorhabditis Elegans ◽  
Myosin Heavy Chain ◽  
Muscle Cell ◽  
Heavy Chain ◽  
Body Wall ◽  
Muscle Development ◽  
Contractile Function ◽  
The Body ◽  
Body Wall Muscle ◽  
Genetic Loci

Abstract We have used available chromosomal deficiencies to screen for genetic loci whose zygotic expression is required for formation of body-wall muscle cells during embryogenesis in Caenorhabditis elegans. To test for muscle cell differentiation we have assayed for both contractile function and the expression of muscle-specific structural proteins. Monoclonal antibodies directed against two myosin heavy chain isoforms, the products of the unc-54 and myo-3 genes, were used to detect body-wall muscle differentiation. We have screened 77 deficiencies, covering approximately 72% of the genome. Deficiency homozygotes in most cases stain with antibodies to the body-wall muscle myosins and in many cases muscle contractile function is observed. We have identified two regions showing distinct defects in myosin heavy chain gene expression. Embryos homozygous for deficiencies removing the left tip of chromosome V fail to accumulate the myo-3 and unc-54 products, but express antigens characteristic of hypodermal, pharyngeal and neural development. Embryos lacking a large region on chromosome III accumulate the unc-54 product but not the myo-3 product. We conclude that there exist only a small number of loci whose zygotic expression is uniquely required for adoption of a muscle cell fate.

scholarly journals Expression patterns of signalling molecules and transcription factors in the early rabbit embryo and their significance for modelling amniote axis formation

2021 ◽  
Author(s):  
Ruben Plöger ◽  
Christoph Viebahn
Keyword(s):  
Transcription Factors ◽  
Expression Patterns ◽  
In Situ Hybridisation ◽  
Body Plan ◽  
The Body ◽  
Anchor Point ◽  
Axis Formation ◽  
Point Model ◽  
Signalling Molecules ◽  
Rabbit Embryo

AbstractThe anterior-posterior axis is a central element of the body plan and, during amniote gastrulation, forms through several transient domains with specific morphogenetic activities. In the chick, experimentally proven activity of signalling molecules and transcription factors lead to the concept of a ‘global positioning system’ for initial axis formation whereas in the (mammotypical) rabbit embryo, a series of morphological or molecular domains are part of a putative ‘three-anchor-point model’. Because circular expression patterns of genes involved in axis formation exist in both amniote groups prior to, and during, gastrulation and may thus be suited to reconcile these models, the expression patterns of selected genes known in the chick, namely the ones coding for the transcription factors eomes and tbx6, the signalling molecule wnt3 and the wnt inhibitor pkdcc, were analysed in the rabbit embryonic disc using in situ hybridisation and placing emphasis on their germ layer location. Peripheral wnt3 and eomes expression in all layers is found initially to be complementary to central pkdcc expression in the hypoblast during early axis formation. Pkdcc then appears — together with a posterior-anterior gradient in wnt3 and eomes domains — in the epiblast posteriorly before the emerging primitive streak is marked by pkdcc and tbx6 at its anterior and posterior extremities, respectively. Conserved circular expression patterns deduced from some of this data may point to shared mechanisms in amniote axis formation while the reshaping of localised gene expression patterns is discussed as part of the ‘three-anchor-point model’ for establishing the mammalian body plan.

scholarly journals Cloning and sequencing of cDNA of Sarcophaga peregrina humoral lectin induced on injury of the body wall.

1985 ◽  
Vol 260 (22) ◽  
pp. 12228-12233 ◽  
Author(s):  
H Takahashi ◽  
H Komano ◽  
N Kawaguchi ◽  
N Kitamura ◽  
S Nakanishi ◽  
...  
Keyword(s):  
Body Wall ◽  
The Body ◽  
Cloning And Sequencing

scholarly journals Mutations Affecting Nerve Attachment of Caenorhabditis elegans

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1611-1622 ◽  
Author(s):  
Go Shioi ◽  
Michinari Shoji ◽  
Masashi Nakamura ◽  
Takeshi Ishihara ◽  
Isao Katsura ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Body Wall ◽  
The Body ◽  
Genetic Loci ◽  
Muscle Attachment ◽  
C Elegans ◽  
Ventral Cord ◽  
Excretory Canal

Abstract Using a pan-neuronal GFP marker, a morphological screen was performed to detect Caenorhabditis elegans larval lethal mutants with severely disorganized major nerve cords. We recovered and characterized 21 mutants that displayed displacement or detachment of the ventral nerve cord from the body wall (Ven: ventral cord abnormal). Six mutations defined three novel genetic loci: ven-1, ven-2, and ven-3. Fifteen mutations proved to be alleles of previously identified muscle attachment/positioning genes, mup-4, mua-1, mua-5, and mua-6. All the mutants also displayed muscle attachment/positioning defects characteristic of mua/mup mutants. The pan-neuronal GFP marker also revealed that mutants of other mua/mup loci, such as mup-1, mup-2, and mua-2, exhibited the Ven defect. The hypodermis, the excretory canal, and the gonad were morphologically abnormal in some of the mutants. The pleiotropic nature of the defects indicates that ven and mua/mup genes are required generally for the maintenance of attachment of tissues to the body wall in C. elegans.

The cuticle of adultNippostrongylus brasiliensis

Parasitology ◽  
1965 ◽  
Vol 55 (1) ◽  
pp. 173-181 ◽  
Author(s):  
D. L. Lee
Keyword(s):  
Electron Microscope ◽  
Body Wall ◽  
Technical Assistance ◽  
Cortical Layer ◽  
The Body ◽  
Collagen Fibrils ◽  
Intestinal Cells ◽  
Nippostrongylus Brasiliensis ◽  
Normal Appearance

The cuticle of adults ofNippostrongylus brasiliensishas been described using histological, histochemical and ultrastructural techniques.The cuticle has the following layers: an outer triple-layered membrane; a single cortical layer; a fluid-filled layer which is traversed by numerous collagen fibrils; struts which support the fourteen longitudinal ridges of the cuticle and which are suspended by collagen fibrils in the fluid-filled layer; two fibre layers, each layer apparently containing three layers of fibres; and a basement lamella.The fluid-filled layer contains haemoglobin and esterase.The muscles of the body wall are attached to either the basement lamella or to the fibre layers of the cuticle.The mitochondria of the hypodermis are of normal appearance.The longitudinal ridges of the cuticle appear to abrade the microvilli of the intestinal cells of the host.Possible functions of the cuticle are discussed.I wish to thank Dr P. Tate, in whose department this work was done, for helpful suggestions and criticism at all stages of this work, and Mr A. Page for technical assistance. I also wish to thank Professor Boyd for permission to use the electron microscope in the Department of Anatomy.

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