scholarly journals Brachial muscles in the chick embryo: the fate of individual somites

Development ◽  
1983 ◽  
Vol 77 (1) ◽  
pp. 99-116
Author(s):  
Bonnie Beresford

The wing and wing-associated muscles of the shoulder and thorax in the bird all cleavefrom common myogenic masses in the developing wing bud and are referred to collectively as brachial muscles. In this study the precise embryonic origin of the brachial muscles was determined using chick-quail chimaeras. Such chimaeras consisted of a graft of one somite taken from a 2-day quail donor embryo transplanted to the equivalent location in a 2-day chick host embryo. The chimaeras were analysed at 9·5–10·0 days in ovo to determine the location of the grafted cells and therefore the structures that were derived from the transplanted somite. The somites that were studied in this manner were somites 13 to 23 inclusive. The results show that only somites 16 to 21 inclusive contribute cells to the brachial musculature; moreover, the cells from a given somite are not distributed randomly among the brachial muscles but populate specific muscles only: thus it has been possible to map the somitic origin of individual brachial muscles. Moreover, there is an indication that each somite plays a unique role in the development of the brachial muscles.

Development ◽  
1986 ◽  
Vol 95 (1) ◽  
pp. 147-168
Author(s):  
Jane Butler ◽  
Peter Cauwenbergs ◽  
Ethel Cosmos

The extent of interaction between brachial muscles and foreign (thoracic) nerves of the chick embryo was determined during an extended period of development in ovo from the perspectives of innervation pattern, function (motility analyses), muscle growth (quantitative analyses of muscle volume) and fibre-type expression (myosin-ATPase profiles). Results indicated that according to all parameters analysed, initially a compatible union existed between the foreign nerves and their muscle targets. During subsequent stages of development, deterioration of the once compatible relationship emerged, until eventually denervation of muscles, i.e. an actual loss of intramuscular nerve branches, was observed. The process of denervation, which proceeded at a differential rate among individual muscles, however was restricted to brachial muscles derived from the premuscle masses of the wing bud. In contrast, brachial muscles of myotomal origin were spared the fate of wing-bud-derived muscles and maintained a successful union with the foreign nerves.


Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 959-970 ◽  
Author(s):  
C. Roberts ◽  
N. Platt ◽  
A. Streit ◽  
M. Schachner ◽  
C.D. Stern

The pattern of expression of the carbohydrate epitope L5 was studied during early development of the chick neuroepithelium. Immunoreactivity first appears during gastrulation, at mid-primitive streak stage, and persists until at least 3.5 days of development. The epitope is expressed on all the components of the developing nervous system, both central and peripheral. In immunoblots, the antibody recognises a major component of about Mr 500,000 and several more minor components of lower molecular mass. If a Hensen's node from a donor embryo is transplanted into the area opaca of a host embryo, L5 immunoreactivity appears in the epiblast surrounding the graft. If hybridoma cells secreting the antibody are grafted together with Hensen's node into a host chick embryo, the induction of a supernumerary nervous system is inhibited. We suggest that the L5 epitope is an early and general marker for neural induction and that it may be involved directly in inductive interactions.


Endocrinology ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 388-399 ◽  
Author(s):  
Youli Hu ◽  
Subathra Poopalasundaram ◽  
Anthony Graham ◽  
Pierre-Marc Bouloux

Fibroblast growth factor (FGF) signaling is essential for both olfactory bulb (OB) morphogenesis and the specification, migration, and maturation of the GnRH-secreting neurons. Disruption of FGF signaling contributes to Kallmann syndrome characterized by both anosmia and sexual immaturity. However, several unanswered questions remain as to which specific FGF receptor (FGFR)-1 signaling pathways are necessary for OB and GnRH neuronal development. Here, using pharmacological phosphatidylinositol 3-kinase (PI3K) isoform-specific inhibitors, we demonstrate a central role for the PI3K p110α isoform as a downstream effector of FGFR1 signaling for both GnRH neuronal migration and OB development. We show that signaling via the PI3K p110α isoform is required for GnRH neuronal migration in explant cultures of embryonic day (E) 4 chick olfactory placodes. We also show that in ovo administration of LY294002, a global PI3K inhibitor as well as an inhibitor to the PI3K p110α isoform into the olfactory placode of E3 chick embryo impairs GnRH neuronal migration toward the forebrain. In contrast, in ovo PI3K inhibitor treatment produced no obvious defects on primary olfactory sensory neuron axonal targeting and bundle formation. We also demonstrate that anosmin-1 and FGF2 induced neuronal migration of immortalized human embryonic GnRH neuroblast cells (FNC-B4-hTERT) is mediated by modulating FGFR1 signaling via the PI3K p110α isoform, specifically through phosphorylation of the PI3K downstream effectors, Akt and glycogen synthase kinase-3β. Finally, we show that neurite outgrowth and elongation of OB neurons in E10 chick OB explants are also dependent on the PI3K p110α isoform downstream of FGFR1. This study provides mechanistic insight into the etiology of Kallmann syndrome.


1998 ◽  
Vol 76 (6) ◽  
pp. 1079-1091 ◽  
Author(s):  
Boris Kablar ◽  
Atsushi Asakura ◽  
Kirsten Krastel ◽  
Chuyan Ying ◽  
Linda L May ◽  
...  

Mounting evidence supports the notion that Myf-5 and MyoD play unique roles in the development of epaxial (originating in the dorso-medial half of the somite, e.g. back muscles) and hypaxial (originating in the ventro-lateral half of the somite, e.g. limb and body wall muscles) musculature. To further understand how Myf-5 and MyoD genes co-operate during skeletal muscle specification, we examined and compared the expression pattern of MyoD-lacZ (258/-2.5lacZ and MD6.0-lacZ) transgenes in wild-type, Myf-5, and MyoD mutant embryos. We found that the delayed onset of muscle differentiation in the branchial arches, tongue, limbs, and diaphragm of MyoD-/- embryos was a consequence of a reduced ability of myogenic precursor cells to progress through their normal developmental program and not because of a defect in migration of muscle progenitor cells into these regions. We also found that myogenic precursor cells for back, intercostal, and abdominal wall musculature in Myf-5-/-embryos failed to undergo normal translocation or differentiation. By contrast, the myogenic precursors of intercostal and abdominal wall musculature in MyoD-/- embryos underwent normal translocation but failed to undergo timely differentiation. In conclusion, these observations strongly support the hypothesis that Myf-5 plays a unique role in the development of muscles arising after translocation of epithelial dermamyotome cells along the medial edge of the somite to the subjacent myotome (e.g., back or epaxial muscle) and that MyoD plays a unique role in the development of muscles arising from migratory precursor cells (e.g., limb and branchial arch muscles, tongue, and diaphragm). In addition, the expression pattern of MyoD-lacZ transgenes in the intercostal and abdominal wall muscles of Myf-5-/- and MyoD-/- embryos suggests that appropriate development of these muscles is dependent on both genes and, therefore, these muscles have a dual embryonic origin (epaxial and hypaxial).Key words: epaxial and hypaxial muscle, Myf-5, MyoD, mouse development, somite.


Development ◽  
1992 ◽  
Vol 114 (3) ◽  
pp. 729-741 ◽  
Author(s):  
K.G. Storey ◽  
J.M. Crossley ◽  
E.M. De Robertis ◽  
W.E. Norris ◽  
C.D. Stern

Induction and regionalisation of the chick nervous system were investigated by transplanting Hensen's node into the extra-embryonic region (area opaca margin) of a host embryo. Chick/quail chimaeras were used to determine the contributions of host and donor tissue to the supernumerary axis, and three molecular markers, Engrailed, neurofilaments (antibody 3A10) and XlHbox1/Hox3.3 were used to aid the identification of particular regions of the ectopic axis. We find that the age of the node determines the regions of the nervous system that form: young nodes (stages 2–4) induced both anterior and posterior nervous system, while older nodes (stages 5–6) have reduced inducing ability and generate only posterior nervous system. By varying the age of the host embryo, we show that the competence of the epiblast to respond to neural induction declines after stage 4. We conclude that during normal development, the initial steps of neural induction take place before stage 4 and that anteroposterior regionalisation of the nervous system may be a later process, perhaps associated with the differentiating notochord. We also speculate that the mechanisms responsible for induction of head CNS differ from those that generate the spinal cord: the trunk CNS could arise by homeogenetic induction by anterior CNS or by elongation of neural primordia that are induced very early.


Development ◽  
1963 ◽  
Vol 11 (1) ◽  
pp. 119-134
Author(s):  
J. B. Solomon ◽  
D. F. Tucker

The immunological attack by adult cells introduced into the embryo is first manifest by splenomegaly. The extent of this splenomegaly depends upon many factors. There must be antigenic differences between the donor and host in that the host must possess antigens absent in the donor (Cock & Simonsen, 1958; Mun, Kosin & Sato, 1959; Burnet & Boyer, 1961; Jaffe & Payne, 1961). The degree of splenomegaly also depends upon the immunological maturity of the donor cells (Ebert, 1951; Simonsen, 1957; Solomon, 1960, 1961a), the number of donor cells injected into the embryo (Isacson, 1959; Terasaki, 1959a; Solomon, 1962) and, in some cases, upon the sex of the host (Solomon, 1962). In this paper two further factors are shown to affect splenomegaly—the age of the host embryo and the method of administration of the donor cells. Danchakoff (1916) first showed that the histology of the spleen during splenomegaly varied with the age of the host without being aware of the nature of the transplantation reactions involved.


1974 ◽  
Vol 38 (1) ◽  
pp. 41-50 ◽  
Author(s):  
John W. Saunders ◽  
Cecelia Reuss
Keyword(s):  

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