Effets de la vinblastine sur la morphogenèse du pied de l'embryon de poulet. Aspects histologiques

Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 609-632
Author(s):  
Par Madeleine Kieny
Keyword(s):  
Distribution Pattern ◽  
Mitotic Index ◽  
Limb Development ◽  
Recent Literature ◽  
Temporary Increase ◽  
Chick Embryos ◽  
Amniotic Cavity ◽  
Marginal Sinus ◽  
Cell Counts ◽  
Maximum Value

Vinblastine was injected into the amniotic cavity of 6·5-day-old chick embryos. Acropods were fixed 0, 2, 3·5, 6, 12, 18, 24, 36 and 48 h after treatment and 1 µm thick sections were prepared from the region of digit IV and interdigit III–IV. Cell counts were mainly performed in a distal zone (see Fig. 2) comprising the ectodermal apical ridge, the distal non-ridge ectoderm and the distal underlying mesoderm. In control non-treated embryos, the mitotic index does not vary significantly in either of the three tissues between 6·5 and 8 days except for a temporary increase at 7 days in the mesoderm. In treated embryos, the mitotic index increases rapidly in the non-ridge ectoderm and in the mesoderm to a maximum of 44 and 35% respectively, 18 h after injection, after which it decreases almost as rapidly to a level of about 15 % 36 h after injection. In the apical ridge ectoderm, the increase of the mitotic index is much slower and reaches its maximum value of about 30 % only 36 h after injection. This suggests that most of the cells participating in the AER do not arise within the ridge but are generated in more proximal zones of the ectoderm. Due to mitotic arrest, the number of mesodermal cells is thus decreased to approximately half the normal value within 36 h and the AER disappears earlier than normal. These alterations are the direct cause of the hypophalangy observed at the morphological level. A particular distribution pattern of arrested mitoses is revealed: in the digital as well as in the interdigital mesoderm, the majority of blocked metaphases is located in a dorsal and a ventral wing-shaped subectodermal 500 µm long area whose thickness is maximal at the level of the marginal sinus and gradually decreases in proximal direction. In the central-part of the mesoderm blocked mitoses are relatively rare. The present results are discussed in view of the recent literature on the morphogenetic processes of limb development.

Role of the chicken homeobox-containing genes GHox-4.6 and GHox-8 in the specification of positional identities during the development of normal and polydactylous chick limb buds

Development ◽  
1992 ◽  
Vol 115 (2) ◽  
pp. 629-637 ◽  
Author(s):  
C.N. Coelho ◽  
W.B. Upholt ◽  
R.A. Kosher
Keyword(s):  
Limb Development ◽  
Ectopic Expression ◽  
Limb Bud ◽  
Chick Embryos ◽  
Limb Buds ◽  
Hox Gene ◽  
Wing Bud ◽  
Coated Bead ◽  
Experimentally Induced

During early stages of normal chick limb development, the homeobox-containing (HOX) gene GHox-4.6 is expressed throughout the posterior mesoderm of the wing bud from which most of the skeletal elements including the digits will develop, whereas GHox-8 is expressed in the anterior limb bud mesoderm which will not give rise to skeletal elements. In the present study, we have examined the expression of GHox-4.6 and GHox-8 in the wing buds of two polydactylous mutant chick embryos, diplopodia-5 and talpid2, from which supernumerary digits develop from anterior limb mesoderm, and have also examined the expression of these genes in response to polarizing zone grafts and retinoic acid-coated bead implants which induce the formation of supernumerary digits from anterior limb mesoderm. We have found that the formation of supernumerary digits from the anterior mesoderm in mutant and experimentally induced polydactylous limb buds is preceded by the ectopic expression of GHox-4.6 in the anterior mesoderm and the coincident suppression of GHox-8 expression in the anterior mesoderm. These observations suggest that the anterior mesoderm of the polydactylous limb buds is “posteriorized” and support the suggestion that GHox-8 and GHox-4.6, respectively, are involved in specifying the anterior non-skeletal and posterior digit-forming regions of the limb bud. Although the anterior mesodermal domain of GHox-8 expression is severely impaired in the mutant and experimentally induced polydactylous limb buds, this gene is expressed by the prolonged, thickened apical ectodermal ridges of the polydactylous limb buds that extend along the distal anterior as well as the distal posterior mesoderm.(ABSTRACT TRUNCATED AT 250 WORDS)

Limb development in the polydactylous talpid3 mutant of the fowl

Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 385-404
Author(s):  
J. R. Hinchliffe ◽  
D. A. Ede
Keyword(s):  
Limb Development ◽  
Vertebral Column ◽  
Autosomal Recessive ◽  
Body Wall ◽  
The Body ◽  
Chick Embryos ◽  
Common Pattern ◽  
Feather Follicle ◽  
Recessive Genes

The three groups of abnormal chick embryos known as talpids show a common pattern of remarkably widespread pleiotropic abnormalities, thought to represent the homozygous expression of one or other of three autosomal recessive genes, symbolized respectively as ta1, ta2, ta3. Ede & Kelly (1964 a, b) described in detail the abnormalities of the talpid3 embryos (ta3/ta3), which are essentially similar to those in Cole's talpid (ta1/ta1) (Inman, 1946), while homozygotes for talpid2 (Abbott, Taylor & Abplanalp, 1960) survive longer and, unlike the others, have relatively normal heads. All three possess at 11 days the following trunk abnormalities: (1) a shortening of the vertebral column accompanied by much fusion of adjacent vertebrae; (2) failure of cartilage replacement by bone; (3) substantial subcutaneous oedema and failure of the body wall to close ventrally round the viscera; (4) abnormal feather follicle formation; and (5) polydactyly in the shortened limbs. In the head of ta1/ta1 and ta3/ta3 embryos both the eyes and the maxillary processes are drawn together in the midline.

Control of growth related to pattern specification in chick wing-bud mesenchyme

Development ◽  
1981 ◽  
Vol 65 (Supplement) ◽  
pp. 169-185
Author(s):  
Jonathan Cooke ◽  
Dennis Summerbell
Keyword(s):  
Mitotic Index ◽  
Packing Density ◽  
Limb Development ◽  
Limb Mesenchyme ◽  
Wing Bud ◽  
Zone Of Polarizing Activity ◽  
Pattern Specification ◽  
Limb Pattern

The distribution of raised mitotic index, and the co-incidence of this with lowered cell packing density, has been studied across the anteroposterior dimension of the terminal 500 μm of chick wing buds following various numbers of hours signalling from an anteriorly grafted extra Zone of Polarizing Activity (ZPA). The results show propagation of the situation that causes these correlated phenomena, from graft-host interface essentially right across the limb mesenchyme, frequently within 8 h. This contrasts with the much slower and more local succession of changes in position memory, for differentiation of a duplicated limb pattern, that also occurs in mesenchyme relatively close to the graft after this operation. The results are discussed, in relation to current ideas about the control of pattern during limb development.

The chick limbless mutation causes abnormalities in limb bud dorsal-ventral patterning: implications for the mechanism of apical ridge formation

Development ◽  
1996 ◽  
Vol 122 (12) ◽  
pp. 3851-3861 ◽  
Author(s):  
U. Grieshammer ◽  
G. Minowada ◽  
J.M. Pisenti ◽  
U.K. Abbott ◽  
G.R. Martin
Keyword(s):  
Gene Expression ◽  
Limb Development ◽  
Positional Information ◽  
Limb Bud ◽  
Local Application ◽  
Chick Embryos ◽  
Limb Buds ◽  
Early Stages ◽  
Potential Link

In chick embryos homozygous for the limbless mutation, limb bud outgrowth is initiated, but a morphologically distinct apical ridge does not develop and limbs do not form. Here we report the results of an analysis of gene expression in limbless mutant limb buds. Fgf4, Fgf8, Bmp2 and Msx2, genes that are expressed in the apical ridge of normal limb buds, are not expressed in the mutant limb bud ectoderm, providing molecular support for the hypothesis that limb development fails in the limbless embryo because of the inability of the ectoderm to form a functional ridge. Moreover, Fgf8 expression is not detected in the ectoderm of the prospective limb territory or the early limb bud of limbless embryos. Since the early stages of limb bud outgrowth occur normally in the mutant embryos, this indicates that FGF8 is not required to promote initial limb bud outgrowth. In the absence of FGF8, Shh is also not expressed in the mutant limb buds, although its expression can be induced by application of FGF8-soaked beads. These observations support the hypothesis that Fgf8 is required for the induction of Shh expression during normal limb development. Bmp2 expression was also not detected in mutant limb mesoderm, consistent with the hypothesis that SHH induces its expression. In contrast, SHH is not required for the induction of Hoxd11 or Hoxd13 expression, since expression of both these genes was detected in the mutant limb buds. Thus, some aspects of mesoderm A-P patterning can occur in the absence of SHH and factors normally expressed in the apical ridge. Intriguingly, mutant limbs rescued by local application of FGF displayed a dorsalized feather pattern. Furthermore, the expression of Wnt7a, Lmx1 and En1, genes involved in limb D-V patterning, was found to be abnormal in mutant limb buds. These data suggest that D-V patterning and apical ridge formation are linked, since they show that the limbless mutation affects both processes. We present a model that explains the potential link between D-V positional information and apical ridge formation, and discuss the possible function of the limbless gene in terms of this model.

An Overview of IoT Infrastructure Architecture, Enabling Technologies, Issues, Integration of Cloud, and Simulation Tools

2022 ◽  
pp. 20-38
Author(s):  
Mobasshir Mahbub
Keyword(s):  
Recent Literature ◽  
Real Life ◽  
Social Aspects ◽  
Simulation Tools ◽  
Critical Studies ◽  
Maximum Value ◽  
Enabling Technologies

Many critical studies and research were carried out to improve the technologies of IoT. Nevertheless, several challenges need to be solved to determine the maximum value of IoT. These problems and concerns will be approached from specific IoT perspectives, such as applications, enabling technologies, issues, and so on. The key purpose of this work is to explore IoT technology in terms of technical and social aspects. The work discusses various challenges and major issues of IoT including detailed architecture and applications. The research further summarizes the recent literature of various areas of IoT and explains their importance. Moreover, the importance of integration of cloud in IoT infrastructure has been discussed. The research also mentioned and described various simulation tools through which the characteristics of the IoT environment can be analyzed empirically. This work lets the readers and the researchers grasp the IoT and its real-life applicability.

A Study of Teratogenic Effects of Particulate Compounds in the Amniotic Cavity of Chick Embryos.

1967 ◽  
Vol 124 (2) ◽  
pp. 524-532 ◽  
Author(s):  
A. P. Williamson ◽  
R. J. Blattner ◽  
G. G. Robertson
Keyword(s):  
Chick Embryos ◽  
Teratogenic Effects ◽  
Amniotic Cavity

scholarly journals Retinoids reprogramme pre-bud mesenchyme to give changes in limb pattern

Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 723-733 ◽  
Author(s):  
S.M. Wilde ◽  
S.E. Wedden ◽  
C. Tickle
Keyword(s):  
Retinoic Acid ◽  
Effective Treatment ◽  
Limb Development ◽  
Apical Ectodermal Ridge ◽  
Limb Bud ◽  
Chick Embryos ◽  
Early Stages ◽  
Limb Pattern

Retinoic acid was locally applied to presumptive limb regions of chick embryos to find out the earliest time at which the limb pattern can be reprogrammed. When beads soaked in retinoic acid were placed in the appropriate positions in embryos at stage 10 or older, duplicated or reduced leg patterns resulted. To pin point the time at which the cells in the limb rudiment respond to the retinoid, beads were removed at various times and the lengths of exposure required to reprogramme limb development found. The early limb rudiments require longer exposures to give duplications than late rudiments. The effective treatment periods last at least until stage 17 when the limb bud and apical ectodermal ridge develop. In contrast, the length of exposure to reduce the limb is constant at early stages. Retinoids first start acting to produce duplicated structures between stages 10 and 13. Therefore, retinoids appear to begin to reprogramme the cells as soon as they are determined to give rise to a limb.

Enhancement of Growth of Chick Host Spleens following Chorio-allantoic Membrane Grafts of Homologous Tissues1

Development ◽  
1959 ◽  
Vol 7 (4) ◽  
pp. 512-525
Author(s):  
A. M. Mun ◽  
I. L. Kosin ◽  
I. Sato
Keyword(s):  
Chick Embryo ◽  
Mitotic Index ◽  
Chick Embryos ◽  
Adult Chicken ◽  
Chicken Tissues ◽  
Chicken Spleen ◽  
Organ Specific ◽  
Excellent Tool

The phenomenon of enlargement of the host chick embryo spleen, following grafts of homologous adult chicken tissues to the chorio-allantoic membrane (CAM), affords the investigator an excellent tool for the study of growth. Initial observations of this phenomenon were made by Danchakoff (1916) and Murphy (1916). Grafts of adult chicken spleen on the chorio-allantoic membrane of 9-day-old chick embryos brought about a striking enlargement of the host spleens after 8 additional days of incubation. The phenomenon was later studied by Ebert (1951), who showed that the effect was only partially organ-specific. Grafts of thymus and liver affected the weight of the host spleen, but in each case the effect was far smaller than that observed with splenic transplants. Andres (1955) found that injected kidney and liver debris, which elicited an increased mitotic index in the homologous host organ, was not inhibited in its action by killing the cells through freezing and subsequent thawing.

The limb identity gene Tbx5 promotes limb initiation by interacting with Wnt2b and Fgf10

Development ◽  
2002 ◽  
Vol 129 (22) ◽  
pp. 5161-5170 ◽  
Author(s):  
Jennifer K. Ng ◽  
Yasuhiko Kawakami ◽  
Dirk Büscher ◽  
Ángel Raya ◽  
Tohru Itoh ◽  
...  
Keyword(s):  
Limb Development ◽  
Gene Families ◽  
Chick Embryos ◽  
Loss Of Function ◽  
T Box ◽  
Vertebrate Limb ◽  
Limb Outgrowth ◽  
Tbx5 Expression ◽  
Necessary And Sufficient ◽  
Limb Initiation

A major gap in our knowledge of development is how the growth and identity of tissues and organs are linked during embryogenesis. The vertebrate limb is one of the best models to study these processes. Combining mutant analyses with gain- and loss-of-function approaches in zebrafish and chick embryos, we show that Tbx5, in addition to its role governing forelimb identity,is both necessary and sufficient for limb outgrowth. We find thatTbx5 functions downstream of WNT signaling to regulateFgf10, which, in turn, maintains Tbx5 expression during limb outgrowth. Furthermore, our results indicate that Tbx5 andWnt2b function together to initiate and specify forelimb outgrowth and identity. The molecular interactions governed by members of the T-box,Wnt and Fgf gene families uncovered in this study provide a framework for understanding not only limb development, but how outgrowth and identity of other tissues and organs of the embryo may be regulated.

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