Regeneration in the medial-lateral axis of the insect thoracic segment

Development ◽  
1988 ◽  
Vol 102 (1) ◽  
pp. 175-192
Author(s):  
V. French ◽  
T.F. Rowlands
Keyword(s):  
Mirror Image ◽  
The Body ◽  
Dorsal Midline ◽  
Unequally Spaced ◽  
Polar Coordinate ◽  
Coordinate Model ◽  
Boundary Model ◽  
Almost All ◽  
Pattern Regulation ◽  
Lateral Axis

We have studied pattern regulation in the medial-lateral axis of the insect segment by grafting legs of beetle larvae (Tenebrio molitor) in different orientations into different positions medial and lateral to the leg site. The Boundary Model and Polar Coordinate Model of the insect appendage predict various patterns of supernumerary leg regeneration, and these grafts were designed to test the predictions. When a larval leg is grafted with normal anterior-posterior orientation medial to the normal leg, larvae and subsequent adults bear the graft plus a supernumerary leg. This is located where the lateral edge of the grafted leg confronted medial thorax (from the leg base across to the midline) and is orientated as a mirror image of the graft. The tarsal structure of supernumeraries resulting from grafts of the mesothoracic leg onto the metathorax shows that the supernumeraries may be derived from the graft, the host site or from both sources. Similarly, when a leg is grafted lateral to the leg site, a supernumerary forms at the confrontation between the medial edge of the graft and lateral thorax (from leg base across to the dorsal tergite). These results agree with the predictions of both models and would indicate that the compartments or the positional values extend out from the leg to the midline and the edge of the tergite. The two models differ in their predictions for the number, position and orientation of supernumeraries following 180 degree rotation of the grafted leg. When the rotated graft is placed lateral to the leg, larvae and adults form a single supernumerary which, in accordance with the Polar Coordinate Model, is lateral to the graft and orientated as a mirror image of it. However, the results of the corresponding medial graft cannot be readily explained by either model. Larvae form a single supernumerary either posterior or medial to the graft, suggesting a modified model with unequally spaced positional values, but the subsequent adult supernumeraries are almost all located medially. Experiments involving a graft placed medial to the leg site frequently show duplication of the adult midline suture, an extra branch forming between the thorax and the graft or supernumerary leg. In this case, as in the regeneration of the dorsal midline, the extreme medial structure is formed between two more lateral regions, which need not come from opposite sides of the body, but must have opposite mediolateral polarities. At present, no model can adequately explain all the results of grafting and extirpation on the insect ventral thorax.

Regeneration in the anterior—posterior axis of the insect thoracic segment

Development ◽  
1986 ◽  
Vol 98 (1) ◽  
pp. 137-165
Author(s):  
Vernon French ◽  
Tamara F. Rowlands
Keyword(s):  
Abdominal Segment ◽  
Adjacent Tissue ◽  
Local Pattern ◽  
Shortest Route ◽  
Polar Coordinate ◽  
Coordinate Model ◽  
Deletion Pattern ◽  
Boundary Model ◽  
Third Line ◽  
Anterior Posterior

After removal of a transverse strip of ventral thorax from the beetle, Tenebrio molitor, interaction occurred between epidermis posterior to the mesothoracic leg and that anterior to the metathoracic leg. Depending on the size and position of the excision, this interaction resulted in either the regeneration of the extirpated tissue or its replacement by an A/P reversed pattern of sclerites and supernumerary leg. By either route, local pattern continuity was restored between the normal meso- and metathoracic legs. Similarly, when a leg plus adjacent tissue was extirpated, continuity was restored by leg regeneration or by formation of an A/P reversed duplication of sclerites. The results of these strip excisions can be understood in terms of two current models of the ventral thorax (the Boundary Model and the Polar Coordinate Model), each of which postulates a distinct compartment or region intervening between the epidermis surrounding the bases of successive legs. However, the models do not explain the large differences in the frequency of formation of the duplication/deletion pattern after excisions of different widths. The results are also compatible with a different model, involving an A–P sequence of positional values similar to that proposed for the abdominal segment. Regeneration would restore continuity within the sequence by the shortest route, forming either the midsegment (including the leg) or the intersegmental region. The meso- and metathorax differ in the structure of the ventral sclerites and in the segmentation of the tarsus of the leg. The structures regenerated after the various excisions show that the segment border is not crossed during regeneration and indicate that an A/P compartment border running through the leg is usually also respected. There is no sign, however, of a third line of lineage restriction that would indicate a subdivision of the segment into three compartments (as proposed in the Boundary Model).

Pattern formation and growth in the regenerating limbs of urodelean amphibians

Development ◽  
1981 ◽  
Vol 65 (Supplement) ◽  
pp. 19-36
Author(s):  
Nigel Holder
Keyword(s):  
Quantitative Analysis ◽  
Pattern Formation ◽  
Limb Regeneration ◽  
Polar Coordinate ◽  
Coordinate Model ◽  
Pattern Regulation

The results of numerous types of grafting experiments involving the amputation of symmetrical limbs are described. These experiments were designed to test the tenets of the polar coordinate model. The analysis of the results of these grafts coupled with a quantitative analysis of blastemal shape strongly indicates that pattern regulation during amphibian limb regeneration can be understood in terms of the model.

Maintenance and regulation of cellular handedness in Tetrahymena

Development ◽  
1989 ◽  
Vol 105 (3) ◽  
pp. 457-471
Author(s):  
E.M. Nelsen ◽  
J. Frankel
Keyword(s):  
Positional Information ◽  
Mirror Image ◽  
Local Geometry ◽  
Preferred Direction ◽  
Left Handed ◽  
Polar Coordinate ◽  
Nuclear Events ◽  
Coordinate Model ◽  
Lh Cells ◽  
Lh Rh

The left-handed phenotype of Tetrahymena thermophila (LH) is a global mirror image of its right-handed counterpart (RH). LH cells are ‘wound’ in the opposite direction from that of RH cells with respect to the placement of all structures that are asymmetrically disposed on the cell circumference. However, the local geometry of ciliary rows, including the asymmetrically placed microtubule bands and other accessory structures, is identical in RH and LH cells. Populations of LH cells grow more slowly than those of RH cells, probably because of nutritional problems due to faulty construction of the cell mouth. LH cells, like RH cells, conjugate in a homopolar configuration, while LH cells mate with RH cells in a heteropolar union which suffices to initiate the conjugal nuclear events but is insufficient to allow survival of progeny. Subclonal analyses indicate that reversion of the LH to the RH form is relatively rare. However, the frequency of reversion is greatly increased by conditions that promote the formation of doublets by fission arrest. An analysis of intermediate doublet forms in such cultures strongly suggests that reversion takes place through a specific pathway, with LH-LH doublets regulating to LH-RH forms that then may give rise to RH singlets. The origin and fate of the LH-RH intermediate forms can be explained by applying a modified polar coordinate model of positional information with the proviso that there is a preferred direction for the intercalation of new positional values.

A boundary model for pattern formation in vertebrate limbs

Development ◽  
1983 ◽  
Vol 76 (1) ◽  
pp. 115-137
Author(s):  
Hans Meinhardt
Keyword(s):  
Pattern Formation ◽  
Positional Information ◽  
Cell Types ◽  
Cooperative Interaction ◽  
Main Body ◽  
Polar Coordinate ◽  
Coordinate Model ◽  
Supernumerary Limbs ◽  
Boundary Model

We postulate that positional information for secondary embryonic fields is generated by a cooperative interaction between two pairs of differently determined cell types. Positional information is thus generated at the boundaries between cells of different determination. The latter are assumed to result from the primary pattern formation in the embryo. The application of this model to vertebrate limbs accounts for the pairwise determination of limbs at a particular location, with a particular handedness and alignment to the main body axes of the embryo. It accounts further for the gross difference in the regeneration of double anterior and double posterior amphibian limbs as well as for the formation of supernumerary limbs after certain graft experiments including supernumeraries in which the dorsoventral polarity changes or which consist of two anterior or two posterior halves. Our model provides a feasible molecular basis for the polar coordinate model and successfully handles recently found violations, for instance formation of supernumerary limbs after ipsilateral grafting with 90° rotation. The most frequent types of developmental malformations become explicable. The models allow specific predictions which are fully supported by recent experiments (see the accompanying paper of M. Maden).

Cell division during intercalary regeneration in the cockroach leg

Development ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 57-78
Author(s):  
Hilary Anderson ◽  
Vernon French
Keyword(s):  
Wound Healing ◽  
Cell Division ◽  
Epidermal Cells ◽  
Moult Cycle ◽  
Intercalary Regeneration ◽  
Polar Coordinate ◽  
Coordinate Model ◽  
Local Cell ◽  
Cuticular Structures ◽  
Pattern Regulation

In a series of grafting operations on cockroach legs, epidermal cells from different positions or from the same position on the circumference of the femur were placed together. Where cells from different positions were confronted, new cuticular structures corresponding to the positions which would normally have lain between them were formed during the following moults. At the control junctions, where cells from the same positions were placed together, no new structures were formed. Grafted legs were examined histologically at various times after the operation. The events following grafting fell into four phases: wound healing — when epidermal cells migrated over the wound to re-establish epidermal continuity and cells adjacent to the wound divided to compensate for cell emigration; intercalation — when cell divisions took place at the host-graft borders where there was a positional discrepancy; proliferation — when the general growth of the epidermis occurred by widespread cell division; cuticle secretion — when apolysis occurred, cell division ceased, and cuticle secretion began. The results show that intercalary regeneration is associated with local cell division at the graft-host borders, and that these divisions are not confined to the normal proliferative phase of the moult cycle, but begin much earlier in the cycle, as soon as wound healing is complete. These results support epimorphic models (such as the Polar Coordinate Model) of pattern regulation, where change of positional value is tied to cell division, but they do not discount the possibility of a limited initial morphallactic phase.

Digestibility of nutrients and milk productivity of cows when using the concentrate mixture with the inclusion of rapeseed presscake

2020 ◽  
pp. 48-53
Author(s):  
L. Yarmots ◽  
G. Yarmots ◽  
A. Belenkaya
Keyword(s):  
Protein Digestibility ◽  
High Energy ◽  
Negative Influence ◽  
The Body ◽  
Milk Productivity ◽  
Lactating Cows ◽  
Low Protein ◽  
Concentrate Mixture ◽  
Almost All ◽  
Experimental Group

For ruminants, especially high-yielding animals in addition to the complete supply of animals with protein, its digestibility in the rumen is important. With low protein digestibility in the rumen, the released ammonia will be more effectively used by the rumen microflora, and the undigestible protein in the subsequent sections of the digestive tract can serve as a source of amino acids for the body. The use of concentrate mixtures with the inclusion of local, affordable and cheaper grain feeds, in particular a high-energy and protein ingredient- rapeseed presscake makes it possible to increase the milk productivity of cows throughout lactation. These presscakes are well balanced in their amino acid composition and belong to feeds whose protein has a low degree of digestibility in the rumen. The purpose of the researches was to study the digestibility of nutrients and milk productivity of cows when using the concentrate mixture with the inclusion of rapeseed presscake. In the scientific and economic experiment has been carried out on lactating cows, where the cows of the experimental group in the concentrate mixture of peas has been replaced with rapeseed presscake the digestibility of nutrients in the ration, energy metabolism and milk productivity have been studied. Studies have shown that almost all the nutrients were significantly better digested by the animals of the experimental group. Energy in milk was more allocated by cows of the experimental group by 6,29 MJ. From cows of the experimental group for 100 and 305 days of lactation has been obtained more milk by 6,27 and 7,06 %, respectively, than from control herdmates. The biochemical parameters of blood were within the limits of the physiological norm in animals of both groups. Thus, the replacement of peas with rapeseed presscake in the concentrate mixture did not have a negative influence on the metabolic processes and helped to increase the milk productivity of cows.

scholarly journals Involvement of Huntingtin in Development and Ciliary Beating Regulation of Larvae of the Sea Urchin, Hemicentrotus pulcherrimus

2021 ◽  
Vol 22 (10) ◽  
pp. 5116
Author(s):  
Hideki Katow ◽  
Tomoko Katow ◽  
Hiromi Yoshida ◽  
Masato Kiyomoto
Keyword(s):  
Sea Urchin ◽  
The Body ◽  
Brdu Incorporation ◽  
Wild Type ◽  
Blastula Stage ◽  
Ciliary Beating ◽  
Marker Proteins ◽  
Disease Protein ◽  
Pattern Regulation ◽  
Hemicentrotus Pulcherrimus

The multiple functions of the wild type Huntington’s disease protein of the sea urchin Hemicentrotus pulcherrimus (Hp-Htt) have been examined using the anti-Hp-Htt antibody (Ab) raised against synthetic oligopeptides. According to immunoblotting, Hp-Htt was detected as a single band at around the 350 kDa region at the swimming blastula stage to the prism larva stage. From the 2-arm pluteus stage (2aPL), however, an additional smaller band at the 165 kDa region appeared. Immunohistochemically, Hp-Htt was detected in the nuclei and the nearby cytoplasm of the ectodermal cells from the swimming blastula stage, and the blastocoelar cells from the mid-gastrula stage. The Ab-positive signal was converged to the ciliary band-associated strand (CBAS). There, it was accompanied by several CBAS-marker proteins in the cytoplasm, such as glutamate decarboxylase. Application of Hp-Htt morpholino (Hp-Htt-MO) has resulted in shortened larval arms, accompanied by decreased 5-bromo-2-deoxyuridin (BrdU) incorporation by the ectodermal cells of the larval arms. Hp-Htt-MO also resulted in lowered ciliary beating activity, accompanied by a disordered swirling pattern formation around the body. These Hp-Htt-MO-induced deficiencies took place after the onset of CBAS system formation at the larval arms. Thus, Hp-Htt is involved in cell proliferation and the ciliary beating pattern regulation signaling system in pluteus larvae.

Blood, joy and tears: menarche narratives of undergraduate females in a selected in Nigeria Private University

2017 ◽  
Vol 31 (4) ◽  
Author(s):  
Adenike Adegbayi
Keyword(s):  
Adolescent Health ◽  
Qualitative Methodology ◽  
Private University ◽  
The Body ◽  
Female Adolescent ◽  
Menstrual Period ◽  
Future Health ◽  
Female Relative ◽  
Undergraduate Females ◽  
Almost All

Abstract The aim of the study is to add to the body of knowledge on less researched aspects of female adolescent health in Nigeria. It specifically explored the menarche or first period narratives of 136 young women, focusing on the contents of the discussion that ensued with whom they told when they first got their period using qualitative methodology. It also explores sources of premenstrual information and how the menstrual period is managed. The sample consisted of 136 undergraduate females in Redeemer’s University, Ede, Nigeria. Almost all of the respondents (95%) received information about menstruation from mothers, female relatives and school lessons prior to menarche. The majority of the respondents first told either their mother or a female relative when they first got their period and viewed menarche as a crisis. Two salient themes emerged from the contents of the narratives; celebration and advice. The advice theme was further explored and three advice patterns were identified: being a woman, hygiene and changed dynamics in relationships with males. Data from the present study suggests that only certain aspects of the menstruation discourse have evolved. All respondents reported using sanitary towels during their menstrual period with the majority experiencing cramps regularly and (61%) using pharmalogical agents for remedy. It is envisaged that findings from the study will be useful in future health intervention programmes and research on female adolescent health in Nigeria and elsewhere.

Demonstration of the relationship between MSD and online learning during the COVID-19 pandemic

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kochu Therisa Karingada ◽  
Michael Sony
Keyword(s):  
Online Learning ◽  
Undergraduate Students ◽  
Online Survey ◽  
Cross Sectional Study ◽  
The Body ◽  
Body Parts ◽  
Cross Sectional ◽  
Content Type ◽  
The Right ◽  
Almost All

PurposeThe COVID-19 pandemic lockdown has caught many educational institutions by surprise and warranted an abrupt migration from offline to online learning. This has resulted in an education change, without any time for due consideration, as regards its impact on musculoskeletal disorders (MSD) on students. The purpose of this study is to investigate MSD related to online learning during the COVID-19 pandemic lockdown.Design/methodology/approachA cross-sectional study was conducted on undergraduate students in India. In total, 261 students participated in this online survey.FindingsThe study finds that around 80% of students have reported some symptom in the head, neck and eyes since they started online learning. In total, 58% have reported MSD symptom in the right shoulder and 56% in the right hand fingers. Besides, more than 40 % of students experienced some MSD symptoms, in almost all the body parts studied, due to online learning. Correlation analysis is conducted between time spent on online learning per day and MSD symptoms.Originality/valueThis is the first study conducted on MSD and online learning during COVID-19 pandemic.

Regeneration from duplicating fragments of the Drosophila wing disc

Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 117-126
Author(s):  
Jane Karlsson ◽  
R. J. Smith
Keyword(s):  
Imaginal Disc ◽  
General Rule ◽  
Wing Disc ◽  
The Other ◽  
Posterior Compartment ◽  
Drosophila Wing ◽  
Polar Coordinate ◽  
New Type ◽  
Coordinate Model

It is a general rule that of two complementary Drosophila imaginal disc fragments, one regenerates and the other duplicates. This paper reports an investigation of an exception to this rule. Duplicating fragments from the periphery of the wing disc which lacked presumptive notum were found to regenerate notum structures during and after duplication. The propensity for this was greatest in fragments lying close to the presumptive notum, with the exception of a fragment confined to the posterior compartment, which did not regenerate notum. Structures were added sequentially, and regeneration stopped once most of the notum was present. These results are not easily explained by the polar coordinate model, which states that regeneration cannot occur from duplicating fragments. Since compartments appear to be involved in this type of regeneration as in others, it is suggested that a new type of model is required, one which permits simultaneous regeneration and duplication, and assigns a major role to compartments.

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