Control of maintenance and anteroposterior skeletal differentiation of the anterior mesenchyme of the chick wing bud by its posterior margin (the ZPA)

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 63-82
Author(s):  
J. R. Hinchliffe ◽  
M. Gumpel-Pinot
Keyword(s):  
Posterior Margin ◽  
Anterior Part ◽  
Posterior Part ◽  
Skeletal Element ◽  
Posterior Half ◽  
Anterior Half ◽  
Wing Bud ◽  
Made In

If the posterior half of the chick wing bud (stages 17–22) is excised, the anterior half which normally forms humerus (part), radius and digit 2, forms only a single skeletal element, either humerus or humerus fused with reduced radius. Beginning at 18 h after operation, and continuing to 48 h the anterior and distal mesenchyme in such anterior halves becomes necrotic and the AER regresses. By contrast, if the anterior half of the chick wing bud (stages 17–22) is excised, the posterior half develops as in the normal bud, and forms humerus (part), ulna and digits 3, 4 and 5. Such posterior halves develop no more mesenchymal necrosis than the normal contralateral wing buds and the AER remains healthy. Further, if the excision of the posterior part is made in such a way as to leave in place a part of the zone of polarising activity (ZPA), a normal wing with complete skeleton is formed. Thus in order to survive and differentiate, the anterior part of the wing bud needs a factor supplied by the posterior part containing the ZPA. These results support the view that the ZPA plays a role in controlling the anteroposterior differentiation of the normal wing bud

scholarly journals Identification of salsolinol in the mediobasal hypothalamus of lactating ewes and its relation to suckling-induced prolactin and GH release

2008 ◽  
Vol 198 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Tomasz Misztal ◽  
Konrad Górski ◽  
Dorota Tomaszewska-Zaremba ◽  
Edyta Molik ◽  
Katarzyna Romanowicz
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Prolactin Secretion ◽  
Plasma Prolactin ◽  
Suckling Period ◽  
Mediobasal Hypothalamus ◽  
Blood Samples ◽  
Extracellular Concentration ◽  
Made In

The push–pull perfusions of the infundibular nucleus–median eminence (IN/ME) were made in lactating ewes (n=7) twice, to identify dopamine (DA)-derived salsolinol and the changes in its extracellular concentration in response to suckling. The perfusate collecting period in every ewe consisted of control non-suckling period, 1000–1230 h (five perfusates), and suckling period, 1230–1500 h (next five perfusates). Simultaneously, blood samples were collected from 1000 to 1500 h at 10-min intervals. The perfusate concentrations of salsolinol and DA were measured by HPLC, and plasma prolactin and GH concentrations were assayed by the RIA. Mean concentrations of salsolinol in perfusates collected from the anterior and posterior parts of the IN/ME (according to post-mortem localization of a perfusion site) increased significantly (P<0.05 and P<0.001 respectively) during the suckling period, when compared with those noted during the non-suckling period. While no DA was found in the anterior part, only vestigial amounts of DA were found in a few perfusates collected from the posterior part. Salsolinol was not detected in the IN/ME of ewes 10 weeks after weaning (seasonal anoestrus). Mean plasma prolactin and GH concentrations during suckling were significantly (P<0.001) higher than those noted during the non-suckling period. In conclusion, our current study reveals that salsolinol is present in the IN/ME of lactating ewes and that its extracellular concentration increases during suckling. Moreover, it supports the role of salsolinol as a neurotransmitter involved in the regulatory process of prolactin secretion at least during lactation.

scholarly journals The effect of the zone of polarizing activity (ZPA) on the anterior half of the chick wing bud

Development ◽  
1987 ◽  
Vol 99 (1) ◽  
pp. 99-108
Author(s):  
D.J. Wilson ◽  
J.R. Hinchliffe
Keyword(s):  
Cell Death ◽  
Limb Bud ◽  
Posterior Half ◽  
Rescue Effect ◽  
Bud Development ◽  
Anterior Half ◽  
Survival And Development ◽  
Wing Bud ◽  
Zone Of Polarizing Activity ◽  
Cut Surface

Removal of the posterior half of the chick wing bud between stages 17–22 results in failure of the anterior distal tissue to survive and differentiate. This observation has been interpreted in terms of a requirement by the anterior half of a factor supplied by the posterior half of the limb containing the zone of polarizing activity (ZPA). This relationship has been tested by grafting ZPA tissue to the posterior surface of the anterior half after posterior half removal. Grafts made proximally on the cut surface did not significantly improve survival and development, nor did the ZPA prevent the expansion of the cell death in the ANZ beyond its normal boundaries into the distal mesenchyme. However, when grafted distally the ZPA inhibited cell death in the apical mesenchyme and caused the anterior mesenchyme to change its normal prospective fate (radius and digit 2). In all these cases, in addition to digit 2, digit 3 and frequently also digit 4 differentiated. The anterior half went on to develop a full set of digits and zeugopod parts in almost 50% of cases, although no skeleton resulting from this regulation of the anterior half had totally size regulated. These results demonstrate a developmental ‘rescue’ effect by the ZPA, and further support the view that the ZPA has a central and unique function in normal limb bud development, controlling survival and differentiation of the mesenchyme along the anteroposterior axis.

scholarly journals Association Between The Posterior Part Of The Circle Of Willis And Vertebral Artery Hypoplasia

2019 ◽  
Author(s):  
Virginija Gaigalaite ◽  
Jurate Dementaviciene ◽  
Augenijus Vilimas ◽  
Danute Kalibatiene
Keyword(s):  
Basilar Artery ◽  
Anterior Part ◽  
Posterior Part ◽  
Proximal Part ◽  
Circle Of Willis ◽  
Anterior Circulation ◽  
Vertebrobasilar System ◽  
Vertebral Artery Hypoplasia ◽  
Blood Flow Redistribution ◽  
Made In

AbstractBackgroundIt is not clear whether the configuration of the posterior part of the circle of Willis (CW) depends on the proximal part of the vertebrobasilar system. Our aim is to evaluate the posterior part of CW in association with different size of vertebral arteries (VA) in subjects free from stroke and TIA.Materials and methodsThe present study was based on a sample of 923 subjects free from stroke and TIA who were examined from 2013 through 2018. All the participants underwent MRA examination. The duplex ultrasonographic examination of the extracranial arteries (vertebral and carotid) was performed. VA was defined as hypoplastic (VAH) when VA diameter in the entire course was less than 2.5 mm. We classified the posterior communicating arteries (PCoA) as presence PCoA, absence/hypoplastic PCoA and fetal CW (FCW). The comparison of the posterior part of CW was made in subjects with normal VA and VAH of a different degree (communicating with basilar artery (VAH-BA) and not communicating with the basilar artery and terminating in PICA, neck or aplasia (VAH-PICA)).ResultsFCW was found in 15.9% of subjects, bilaterally – in 2.3 %. The coexisting VAH was more common in subjects with FCW rather than in those with adult CW (respectively, 28.6% and 13.4%, p<0.001). Aplasia of A1 of the anterior cerebral artery, i.e. blood flow redistribution in the anterior part of anterior circulation in the majority of cases (in 6 of 7 cases) was found ipsilaterally to FCW. FCW was recorded in 50% of the subjects with VA - PICA in comparison with 13.5% of those with normal VA and 22.8% with VAH - BA, p<0.005. On the contrary, absence/hypoplasia of both PCoA was mostly found in the group with normal VA in comparison with VAH-BA and VAH-PICA (accordingly, 50.7%, 38.6% and 12.5%, p<0.01).ConclusionIndividuals with VAH have a different pattern of the posterior part of CW in comparison with those with normal VA. With the increasing degree of VAH, the proportion of FCW increases, while the proportion of absence/hypoplastic of both PCoA decreases.

PARTIAL PREPARATORY STAGES OF CATOCALA ILLECTA, WALKER, WITH NOTES

1892 ◽  
Vol 24 (12) ◽  
pp. 307-308
Author(s):  
G. H. French
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
The Body ◽  
The Other ◽  
Ground Colour ◽  
Anterior Half ◽  
Black Spots ◽  
Last Stage

Three days before that last moult, the larva is 1.30 inches; after the last moult and three days before pupating, 2 inches. Nearly cylindrical, tapering from the middle to both ends, the under side a little flattened, a slight fold above the legs but no fringe on the sides. The markings in the two last stages are the same, except that the orange is a little heavier in the last stage. The ground colour of dorsum, sides except below stigmata, and venter sordid white, below stigmata clear white; striped transversely over the back as low as the stigmata, thus leaving a clear white substigmatal stripe, eight of these stripes and these somewhat double, some broken and others partly continuous; a subdorsal and substigmatal row of orange patches, two of each row on each joint, the lower of each side of the stigma on the anterior part of the body, but on the posterior part these patches connect above the stigma, gradually passing from one from to the other; on joint two, instead of two pathces, the anterior half of the joint is orange with a row of black spots; joints three and four with an irregular row of orange across near the middle of the joint.

Nematodirus battus: structure of the body wall of the adult

Parasitology ◽  
1983 ◽  
Vol 86 (3) ◽  
pp. 481-488 ◽  
Author(s):  
Jean Martin ◽  
D. L. Lee
Keyword(s):  
Body Wall ◽  
Longitudinal Muscle ◽  
Posterior Part ◽  
Muscle Cells ◽  
The Body ◽  
Posterior Half ◽  
Anterior Half ◽  
Longitudinal Muscles

SUMMARYMales of Nematodirus battus have a body wall composed of a longitudinally ridged cuticle made up of 8 layers, a hypodermis and a layer of longitudinal muscle cells which are divided into 4 sectors by the hypodermal cords. There is a characteristic cephalic inflation of the cuticle in both sexes. The structure of the body wall in the anterior half of the female is similar to that of the male. In the posterior half of the female the cuticle is not ridged and has 7 layers; the longitudinal muscles are reduced in number and the lateral hypodermal cords increasingly extend dorsally and ventrally along the length of the posterior part of the nematode and come to occupy most of the lateral sectors of the body. The possible significance of these modifications in the structure of the female nematode are discussed.

Fine structure of the rectal papillae of the oriental fruuit fly, Dacus dorsalis Hendel (Tephritidae, Diptera Insecta)

1990 ◽  
Vol 48 (3) ◽  
pp. 498-499
Author(s):  
Len Wen-Yung ◽  
Mei-Jung Lin
Keyword(s):  
Fine Structure ◽  
Cell Membrane ◽  
Intercellular Space ◽  
Anterior Part ◽  
Apical Cell ◽  
Posterior Part ◽  
Apical Cell Membrane ◽  
Dacus Dorsalis ◽  
Radial Cell ◽  
Circular Base

Four cone-shaped rectal papillae locate at the anterior part of the rectum in Dacus dorsalis fly. The circular base of the papilla protrudes into the haemolymph (Fig. 1,2) and the rest cone-shaped tip (Fig. 2) inserts in the rectal lumen. The base is surrounded with the cuticle (Fig. 5). The internal structure of the rectal papilla (Fig. 3) comprises of the cortex with the columnar epithelial cells and a rod-shaped medulla. Between them, there is the infundibular space and many trabeculae connect each other. Several tracheae insert into the papilla through the top of the medulla, then run into the cortical epithelium and locate in the intercellular space. The intercellular sinuses distribute in the posterior part of the rectal papilla.The cortex of the base divides into about thirty segments. Between segments there is a radial cell (Fig. 4). Under the cuticle, the apical cell membrane of the cortical epithelium is folded into a regular border of leaflets (Fig. 5).

scholarly journals The genus Gennadas (Benthesicymidae: Decapoda): morphology of copulatory characters, phylogeny and coevolution of genital structures

2017 ◽  
Vol 4 (12) ◽  
pp. 171288 ◽  
Author(s):  
Alexander L. Vereshchaka ◽  
Anastasia A. Lunina ◽  
Jørgen Olesen
Keyword(s):  
New Species ◽  
Anterior Part ◽  
Phylogenetic Analyses ◽  
Posterior Part ◽  
Key To Species ◽  
Internal Part ◽  
Species Groups ◽  
Aristaeomorpha Foliacea ◽  
External Part ◽  
Scanning Electron

Species within Gennadas differ from each other largely only in male (petasma) and female (thelycum) copulatory characters, which were restudied in scanning electron microscopy and used as a basis for phylogenetic analyses. Twenty-six petasma characters and 49 thelycum characters were identified. All 16 recognized species of Gennadas and Aristaeomorpha foliacea (outgroup) were included as terminals. Four robust monophyletic clades were retrieved, described and diagnosed as new species groups. The thelycum characters had greater impact on tree topology and supported deeper nodes than did the petasma characters. We hypothesize that features of the thelycum evolved first followed by aspects of the petasma. Relatively more conservative characters include parts of the sternites of the thelycum and of the petasma, while the scuti and protuberances on the thelycum and the shape and subdivisions of the petasma lobes are evolutionarily plastic. We identified two groups of copulatory characters, which are likely coupled functionally and interlinked evolutionarily: (i) the external part of the petasma and the posterior part of the thelycum and (ii) the internal part of the petasma and anterior part of the thelycum. We reconstruct possible mating position during copulation for each of the new species groups presented here. We also present an updated key to genera of Benthesicymidae and key to species of Gennadas .

Interacting functions of snail, twist and huckebein during the early development of germ layers in Drosophila

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1137-1150 ◽  
Author(s):  
R. Reuter ◽  
M. Leptin
Keyword(s):  
Transcription Factors ◽  
Digestive Tract ◽  
Early Development ◽  
Target Genes ◽  
Anterior Part ◽  
Posterior Part ◽  
Germ Layers ◽  
Mesoderm Development ◽  
Ventral Furrow

Two zygotic genes, snail (sna) and twist (twi), are required for mesoderm development, which begins with the formation of the ventral furrow. Both twi and sna are expressed ventrally in the blastoderm, encode transcription factors and promote the invagination of the ventral furrow by activating or repressing appropriate target genes. However, sna and twi alone do not define the position of the ventral furrow, since they are also expressed in ventral cells that do not invaginate. We show that huckebein (hkb) sets the anterior and the posterior borders of the ventral furrow, but acts by different modes of regulation. In the posterior part of the blastoderm, hkb represses the expression of sna in the endodermal primordium (which we suggest to be adjacent to the mesodermal primordium). In the anterior part, hkb antagonizes the activation of target genes by twi and sna. Here, bicoid permits the co-expression of hkb, sna and twi, which are all required for the development of the anterior digestive tract. We suggest that mesodermal fate is determined where sna and twi but not hkb are expressed. Anteriorly hkb together with sna determines endodermal fate, and hkb together with sna and twi are required for foregut development.

scholarly journals A new species of Pista Malmgren, 1866 (Polychaeta, Terebellidae) from the north-western Mediterranean Sea

ZooKeys ◽  
2019 ◽  
Vol 838 ◽  
pp. 71-84
Author(s):  
Céline Labrune ◽  
Nicolas Lavesque ◽  
Paulo Bonifácio ◽  
Pat Hutchings
Keyword(s):  
New Species ◽  
Mediterranean Sea ◽  
Anterior Part ◽  
Posterior Part ◽  
Western Mediterranean ◽  
Single Pair ◽  
The North ◽  
Western Mediterranean Sea ◽  
North Western ◽  
A New Species

A new species of Terebellidae, Pistacolinisp. n., has been identified from the harbour of Banyuls-sur-Mer, north-western Mediterranean Sea. This new species was found in very high densities, exclusively in gravelly sand deposited manually, and was not found in the original source habitat of the gravel. This species is characterized by the colour of the ventral shields with pinkish anterior part and a blood red posterior part in live specimens, a pair of unequal-sized plumose branchiae inserted on segment II and anterior thoracic neuropodia with long-handled uncini. The presence of long-handled uncini even in the smallest specimens constitutes the major difference between Pistacolinisp. n. and other Pista species with a single pair of branchiae such as P.lornensis and P.bansei.

scholarly journals Influence of different orientations and rates of bidirectional distraction osteogenesis of the mandibular corpus: a three-dimensional study.

2019 ◽  
Vol S (1) ◽  
pp. 11-14
Author(s):  
Lamiaa A. Hasan ◽  
◽  
Nada M. Al-Sayagh ◽  
Lara R. Al-Banaa ◽  
◽  
...  
Keyword(s):  
Distraction Osteogenesis ◽  
Anterior Part ◽  
Three Dimensional ◽  
Posterior Part ◽  
Von Mises Stress ◽  
Occlusal Plane ◽  
Three Dimensional Model ◽  
Direction Parallel ◽  
Inferior Border ◽  
Von Mises

Objective: The objective of this study was to evaluate the biomechanical effect of mandibular corpus distraction osteogenesis with different orientations and rates. Materials and Methods: A three-dimensional model of the mandible was created. The vertical surgical cut was made, the force was applied horizontally in a bidirectional manner within two orientations: parallel to the occlusal plane and parallel to the inferior border of the mandible with three rates (0.5mm, 1mm and 1.5mm). Results: The maximum values for von Mises stress when the force was applied parallel to the inferior border of the mandible with all three rates were smaller than those with force direction parallel to the occlusal plane. The displacement in all three directions x, y, and z were not parallel and prominent in the anterior part of the mandible, while the movement at the posterior part is negligible, x and z displacement were bigger when force was applied parallel to the inferior border of the mandible, z displacement was more prominent than x and y displacement, both directions produced upward rotation of the mandible, this rotation was more noticeable when the force was applied parallel to the inferior border of the mandible. Conclusions: A vertical cut can be used in the patient with a long anterior face. This site of distraction achieves more lengthening of mandible than expansion.

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