Cellular patterning of fast and slow fibres in the intermandibularis muscle of chick embryos

Development ◽  
1993 ◽  
Vol 117 (1) ◽  
pp. 329-339 ◽  
Author(s):  
L.G. Robson
Keyword(s):  
Cell Types ◽  
Specific Pattern ◽  
Slow Muscle ◽  
Limb Bud ◽  
Muscle Fibres ◽  
Chick Embryos ◽  
Myogenic Cells ◽  
Lower Jaw ◽  
Cellular Pattern

The way in which the pattern of cell types arises during development of individual muscles was explored. The pattern of cellular differentiation resulting from the synthesis of particular fast and slow myosin heavy chains (MyHC) was investigated in the intermandibularis muscle in the lower jaw of chick embryos. The intermandibularis muscle has a proximodistal pattern of fibre type distribution. The distal region of the muscle contains a ratio of 1.5:1 fast to slow muscle fibres, which increases to > 2.5:1 in the proximal region. The intermandibularis muscle is assembled in a proximodistal sequence, with both fast and slow muscle cells differentiating within the earliest muscle and then establishing the specific pattern of cell types. This pattern is not dependent on a specific innervation source, as normal lower jaw muscles develop and the intermandibularis has the same graded cellular pattern when the mandibular primordium is grafted to the limb bud stump. Micromass cultures were used to explore the pool of potentially myogenic cells that are available to construct the muscles. Even before the muscle differentiates in vivo, both fast and slow cells are present in the primordia. These potentially myogenic cells are already distributed within the primordium in a proximodistal fashion that mimics the cellular pattern found in the muscle that develops.

Cell contacts and sorting out in vivo: the behaviour of some embryonic tissues implanted into the developing chick wing

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 225-237
Author(s):  
C. Tickle ◽  
M. Goodman ◽  
L. Wolpert
Keyword(s):  
Neural Tube ◽  
Cell Types ◽  
Neural Retina ◽  
Limb Bud ◽  
Embryonic Liver ◽  
Malignant Cells ◽  
Embryonic Tissues ◽  
Mixed Aggregates ◽  
Wing Bud

The interaction of cells from embryonic liver, neural retina and mesonephros with cells from limb-bud mesenchyme has been investigated in vivo by grafting these tissues into the developing chick wing-bud. The implanted cells were in all cases from quail tissue which can be recognized histologically. As embryonic liver and neural tube are tissues that sort externally to limb-bud mesenchyme in mixed aggregates, it would be expected, from a differential adhesiveness hypothesis, that heterotypic adhesions along the borders of graft and host would be favoured over cell-cell adhesions in the graft. No morphological signs of this were evident: rather the grafted cells maximized like-like contacts. The cells of the grafts, including those from control mesenchyme, did not invade into the wing. The results were the same irrespective of whether the graft was a fragment of tissue or a pellet of reaggregated cells. This supports the idea that cells within tissues are not actively moving around and also provides controls for assaying the invasiveness of other cell types, such as malignant cells into the wing.

Cytokine-induced changes in chromatin structure and in vivo footprints in the inducible NOS promoter

2001 ◽  
Vol 280 (3) ◽  
pp. L390-L399 ◽  
Author(s):  
Jane K. Mellott ◽  
Harry S. Nick ◽  
Michael F. Waters ◽  
Timothy R. Billiar ◽  
David A. Geller ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Protein Interactions ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Specific Pattern ◽  
Mrna Levels ◽  
Inos Gene ◽  
In Vivo Footprinting ◽  
Induced Changes

Transcription of the human inducible nitric oxide synthase ( iNOS) gene is regulated by inflammatory cytokines in a tissue-specific manner. To determine whether differences in cytokine-induced mRNA levels between pulmonary epithelial cells (A549) and hepatic biliary epithelial cells (AKN-1) result from different protein or DNA regulatory mechanisms, we identified cytokine-induced changes in DNase I-hypersensitive (HS) sites in 13 kb of the iNOS 5′-flanking region. Data showed both constitutive and inducible HS sites in an overlapping yet cell type-specific pattern. Using in vivo footprinting and ligation-mediated PCR to detect potential DNA or protein interactions, we examined one promoter region near −5 kb containing both constitutive and cytokine-induced HS sites. In both cell types, three in vivo footprints were present in both control and cytokine-treated cells, and each mapped within a constitutive HS site. The remaining footprint appeared only in response to cytokine treatment and mapped to an inducible HS site. These studies, performed on chromatin in situ, identify a portion of the molecular mechanisms regulating transcription of the human iNOS gene in both lung- and liver-derived epithelial cells.

Expression of laminin isoforms in mouse myogenic cells in vitro and in vivo

1995 ◽  
Vol 108 (12) ◽  
pp. 3795-3805 ◽  
Author(s):  
F. Schuler ◽  
L.M. Sorokin
Keyword(s):  
In Situ Hybridization ◽  
Basement Membranes ◽  
Chain Gene ◽  
Muscle Fibres ◽  
Myogenic Cells ◽  
Mouse Tissues ◽  
Laminin 1

The expression of laminin-1 (previously EHS laminin) and laminin-2 (previously merosin) isoforms by myogenic cells was examined in vitro and in vivo. No laminin alpha 2 chainspecific antibodies react with mouse tissues, 50 rat monoclonal antibodies were raised against the mouse laminin alpha 2 chain: their characterization is described here. Myoblasts and myotubes from myogenic cell lines and primary myogenic cultures express laminin beta 1 and gamma 1 chains and form a complex with a 380 kDa alpha chain identified as laminin alpha 2 by immunofluorescence, immunoprecipitation and PCR. PCR from C2C12 myoblasts and myotubes for the laminin alpha 2 chain gene (LamA2) provided cDNA sequences which were used to investigate the in vivo expression of mouse LamA2 mRNA in embryonic tissues by in situ hybridization. Comparisons were made with specific probes for the laminin alpha 1 chain gene (LamA1). LamA2 but not LamA1 mRNA was expressed in myogenic tissues of 14- and 17-day-old mouse embryos, while the laminin alpha 2 polypeptide was localized in adjacent basement membranes in the muscle fibres. In situ hybridization also revealed strong expression of the LamA2 mRNA in the dermis, indicating that laminin alpha 2 is expressed other than by myogenic cells in vivo. Immunofluorescence studies localized laminin alpha 2 in basement membranes of basal keratinocytes and the epithelial cells of hair follicles, providing new insight into basement membrane assembly during embryogenesis. In vitro cell attachment assays revealed that C2C12 and primary myoblasts adhere to laminin-1 and -2 isoforms in a similar manner except that myoblast spreading was significantly faster on laminin-2. Taken together, the data suggest that laminins 1 and 2 play distinct roles in myogenesis.

scholarly journals Cellular rescue in a zebrafish model of congenital muscular dystrophy type 1A

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
T. E. Hall ◽  
A. J. Wood ◽  
O. Ehrlich ◽  
M. Li ◽  
C. S. Sonntag ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Congenital Muscular Dystrophy ◽  
Cell Types ◽  
Basement Membranes ◽  
Muscle Fibres ◽  
Zebrafish Model ◽  
Diverse Range ◽  
Therapeutic Opportunity ◽  
And Migration

AbstractLaminins comprise structural components of basement membranes, critical in the regulation of differentiation, survival and migration of a diverse range of cell types, including skeletal muscle. Mutations in one muscle enriched Laminin isoform, Laminin alpha2 (Lama2), results in the most common form of congenital muscular dystrophy, congenital muscular dystrophy type 1A (MDC1A). However, the exact cellular mechanism by which Laminin loss results in the pathological spectrum associated with MDC1A remains elusive. Here we show, via live tracking of individual muscle fibres, that dystrophic myofibres in the zebrafish model of MDC1A maintain sarcolemmal integrity and undergo dynamic remodelling behaviours post detachment, including focal sarcolemmal reattachment, cell extension and hyper-fusion with surrounding myoblasts. These observations imply the existence of a window of therapeutic opportunity, where detached cells may be “re-functionalised” prior to their delayed entry into the cell death program, a process we show can be achieved by muscle specific or systemic Laminin delivery. We further reveal that Laminin also acts as a pro-regenerative factor that stimulates muscle stem cell-mediated repair in lama2-deficient animals in vivo. The potential multi-mode of action of Laminin replacement therapy suggests it may provide a potent therapeutic axis for the treatment for MDC1A.

scholarly journals Down-Regulation of Nucleosomal Binding Protein HMGN1 Expression during Embryogenesis Modulates Sox9 Expression in Chondrocytes

2006 ◽  
Vol 26 (2) ◽  
pp. 592-604 ◽  
Author(s):  
Takashi Furusawa ◽  
Jae-Hwan Lim ◽  
Frédéric Catez ◽  
Yehudit Birger ◽  
Susan Mackem ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Chromatin Immunoprecipitation ◽  
Chondrogenic Differentiation ◽  
Nuclear Protein ◽  
Basal Layer ◽  
Cell Types ◽  
Limb Bud ◽  
Wild Type ◽  
Sox9 Expression

ABSTRACT We find that during embryogenesis the expression of HMGN1, a nuclear protein that binds to nucleosomes and reduces the compaction of the chromatin fiber, is progressively down-regulated throughout the entire embryo, except in committed but continuously renewing cell types, such as the basal layer of the epithelium. In the developing limb bud, the expression of HMGN1 is complementary to Sox9, a master regulator of the chondrocyte lineage. In limb bud micromass cultures, which faithfully mimic in vivo chondrogenic differentiation, loss of HMGN1 accelerates differentiation. Expression of wild-type HMGN1, but not of a mutant HMGN1 that does not bind to chromatin, in Hmgn1 −/− micromass cultures inhibits Sox9 expression and retards differentiation. Chromatin immunoprecipitation analysis reveals that HMGN1 binds to Sox9 chromatin in cells that are poised to express Sox9. Loss of HMGN1 elevates the amount of HMGN2 bound to Sox9, suggesting functional redundancy among these proteins. These findings suggest a role for HMGN1 in chromatin remodeling during embryogenesis and in the activation of Sox9 during chondrogenesis.

scholarly journals MyoD, myogenin independent differentiation of primordial myoblasts in mouse somites.

1992 ◽  
Vol 116 (5) ◽  
pp. 1243-1255 ◽  
Author(s):  
M G Cusella-De Angelis ◽  
G Lyons ◽  
C Sonnino ◽  
L De Angelis ◽  
E Vivarelli ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Posttranscriptional Regulation ◽  
Proximal Region ◽  
Limb Bud ◽  
Northern Analysis ◽  
Myogenic Cells

The accumulation of two myogenic regulatory proteins, MyoD and myogenin, was investigated by double-immunocytochemistry and correlated with myosin heavy chain expression in different classes of myoblasts in culture and during early myogenesis in vivo. During in vitro differentiation of fetal myoblasts, MyoD-positive cells were detected first, followed by the appearance of cells positive for both MyoD and myogenin and finally by the appearance of differentiated myocytes and myotubes expressing myosin heavy chain (MHC). A similar pattern of expression was observed in cultures of embryonic and satellite cells. In contrast, most myogenic cells isolated from newly formed somites, expressed MHC in the absence of detectable levels of myogenin or MyoD. In vivo, the appearance of both myogenin and MyoD proteins was only detected at 10.5 d postcoitum (d.p.c.), when terminally differentiated muscle cells could already be identified in the myotome. Parasagittal sections of the caudal myotomes of 10.5-d-old embryos showed that expression of contractile proteins preceded the expression of myogenin or MyoD and, when coexpressed, MHC and myogenin did not co-localize within all the cells of the myotome. In the limb bud, however, many myogenin (or MyoD) positive/MHC negative cells could be observed in the proximal region at day 11. During further embryonic development the expression of these proteins remained constant in all the muscle anlagens examined, decreasing to a low level during the late fetal period. Western and Northern analysis confirmed that the myogenin protein could only be detected after 10.5 d.p.c. while the corresponding message was clearly present at 9.5 d.p.c., strongly suggesting a posttranscriptional regulation of myogenin during this stage of embryonic development. These data show that the first myogenic cells which appear in the mouse myotome, and can be cultured from it, accumulate muscle structural proteins in their cytoplasm without expressing detectable levels of myogenin protein (although the message is clearly accumulated). Neither MyoD message or protein are detectable in these cells, which may represent a distinct myogenic population whose role in development remains to be established.

IGF-I, insulin and FGFs induce outgrowth of the limb buds of amelic mutant chick embryos

Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1323-1330 ◽  
Author(s):  
C.N. Dealy ◽  
R.A. Kosher
Keyword(s):  
Proper Time ◽  
Limb Bud ◽  
Chick Embryos ◽  
In Vitro Morphogenesis ◽  
Limb Buds ◽  
Limb Outgrowth ◽  
Igf I ◽  
High Level

IGF-I, insulin, FGF-2 and FGF-4 have been implicated in the reciprocal interactions between the apical ectodermal ridge (AER) and underlying mesoderm required for outgrowth and patterning of the developing limb. To study further the roles of these growth factors in limb outgrowth, we have examined their effects on the in vitro morphogenesis of limb buds of the amelic mutant chick embryos wingless (wl) and limbless (ll). Limb buds of wl and ll mutant embryos form at the proper time in development, but fail to undergo further outgrowth and subsequently degenerate. Wl and ll limb buds lack thickened AERs capable of promoting limb outgrowth, and their thin apical ectoderms fail to express the homeobox-containing gene Msx-2, which is highly expressed by normal AERs and has been implicated in regulating AER activity. Here we report that exogenous IGF-I and insulin, and, to a lesser extent, FGF-2 and FGF-4 induce the proliferation and directed outgrowth of explanted wl and ll mutant limb buds, which in vitro, like in vivo, normally fail to undergo outgrowth and degenerate. IGF-I and insulin, but not FGFs, also cause the thin apical ectoderms of wl and ll limb buds to thicken and form structures that grossly resemble normal AERs and, moreover, induce high level expression of Msx-2 in these thickened AER-like structures. Neither IGF-I, insulin nor FGFs induce expression of the homeobox-containing gene Msx-1 in the subapical mesoderm of wl or ll limb buds, although FGFs, but not IGF-I or insulin, maintain Msx-1 expression in normal (non-mutant) limb bud explants lacking an AER. The implications of these results to the relationships among the wl and ll genes, IGF-I/insulin, FGFs, Msx-2 and Msx-1 in the regulation of limb outgrowth is discussed.

scholarly journals Differences in decorin expression by papillary and reticular fibroblasts in vivo and in vitro

1993 ◽  
Vol 290 (3) ◽  
pp. 893-899 ◽  
Author(s):  
E Schönherr ◽  
L A Beavan ◽  
H Hausser ◽  
H Kresse ◽  
L A Culp
Keyword(s):  
In Situ Hybridization ◽  
Cultured Cells ◽  
Chondroitin Sulphate ◽  
Cell Types ◽  
Specific Pattern ◽  
Dermatan Sulphate ◽  
Sulphate Proteoglycan

Immunostaining of adult human skin shows that the small dermatan sulphate proteoglycan decorin is abundant in the whole dermal layer but absent from the epidermis. In the papillary layer adjacent to the dermal-epidermal border, more decorin was detected than in the reticular layer of the dermis. Expression of decorin mRNA by cells in the papillary dermis could also be shown by in situ hybridization. In contrast, biglycan, another small chondroitin sulphate/dermatan sulphate proteoglycan, is found only at the dermal-epidermal border. Therefore the biosynthesis of these two proteoglycans by papillary and reticular fibroblasts from two different donors was compared in tissue culture. Papillary fibroblasts secrete up to 5.9 times more decorin than reticular fibroblasts, while the amounts of cell-associated decorin in both cell types are similar. By Northern blot analysis as well as by in situ hybridization it was shown that papillary fibroblasts contain more mRNA coding for decorin than do reticular cells. In addition, no mosaic pattern of decorin expression was found in the cultured cells. The expression and synthesis of biglycan compared with decorin was about 10 times lower and did not show any significant differences for the two cells types. The kinetics of secretion and the rate of endocytosis of decorin were similar for both types of fibroblasts. These results were found with fibroblasts between the 9th and 15th passage from a newborn subject as well as from a 78-year-old donor, indicating that the pattern of decorin synthesis is not age-dependent in the range investigated. These results further show that fibroblasts from different layers of the dermis have a specific pattern of synthesis of small chondroitin sulphate/dermatan sulphate proteoglycans, and they also maintain these patterns in cell culture.

Development of the Foramen Secundum in the Chick as Observed by Scanning Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 212-213
Author(s):  
M.J.C. Hendrix ◽  
D.E. Morse
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Procaine Hydrochloride ◽  
Cardiac Anomaly ◽  
Chick Embryos ◽  
Congenital Cardiac Anomaly ◽  
Septal Defects ◽  
Critical Point Drying ◽  
Scanning Electron

Atrial septal defects are considered the most common congenital cardiac anomaly occurring in humans. In studying the normal sequential development of the atrial septum, chick embryos of the White Leghorn strain were prepared for scanning electron microscopy and the results were then extrapolated to the human heart. One-hundred-eighty chick embryos from 2 to 21 days of age were removed from their shells and immersed in cold cacodylate-buffered aldehyde fixative . Twenty-four embryos through the first week post-hatching were perfused in vivo using cold cacodylate-buffered aldehyde fixative with procaine hydrochloride. The hearts were immediately dissected free and remained in the fixative a minimum of 2 hours. In most cases, the lateral atrial walls were removed during this period. The tissues were then dehydrated using a series of ascending grades of ethanol; final dehydration of the tissues was achieved via the critical point drying method followed by sputter-coating with goldpalladium.

Ultrastructural Study of a differentiating human colon carcinoma cell line

1990 ◽  
Vol 48 (3) ◽  
pp. 208-209
Author(s):  
Sylvie Polak-Charcon ◽  
Mehrdad Hekmati ◽  
Yehuda Ben Shaul
Keyword(s):  
Cell Line ◽  
Morphological Changes ◽  
Secretory Granules ◽  
Human Colon ◽  
Cell Types ◽  
Culture Conditions ◽  
Morphological Evidence ◽  
Human Colon Carcinoma Cell ◽  
Colon Cell

The epithelium of normal human colon mucosa “in vivo” exhibits a gradual pattern of differentiation as undifferentiated stem cells from the base of the crypt of “lieberkuhn” rapidly divide, differentiate and migrate toward the free surface. The major differentiated cell type of the intestine observed are: absorptive cells displaying brush border, goblet cells containing mucous granules, Paneth and endocrine cells containing dense secretory granules. These different cell types are also found in the intestine of the 13-14 week old embryo.We present here morphological evidence showing that HT29, an adenocarcinoma of the human colon cell line, can differentiate into various cell types by changing the growth and culture conditions and mimic morphological changes found during development of the intestine in the human embryo.HT29 cells grown in tissue-culture dishes in DMEM and 10% FCS form at late confluence a multilayer of morphologically undifferentiated cell culture covered with irregular microvilli, and devoid of tight junctions (Figs 1-3).

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