scholarly journals Rhombencephalic neural crest segmentation is preserved throughout craniofacial ontogeny

Development ◽  
1996 ◽  
Vol 122 (10) ◽  
pp. 3229-3242 ◽  
Author(s):  
G. Kontges ◽  
A. Lumsden
Keyword(s):  
Neural Crest ◽  
Cranial Base ◽  
Proximal Region ◽  
Anatomical Landmarks ◽  
Connective Tissues ◽  
Mandibular Arch ◽  
Lower Jaw ◽  
Attachment Sites ◽  
Evolutionary Changes

To investigate the influence of hindbrain segmentation on craniofacial patterning we have studied the long term fate of neural crest (NC) subpopulations of individual rhombomeres (r), using quail-chick chimeras. Mapping of all skeletal and muscle connective tissues developing from these small regions revealed several novel features of the cranial neural crest. First, the mandibular arch skeleton has a composite origin in which the proximal elements are r1+r2 derived, whereas more distal ones are exclusively midbrain derived. The most proximal region of the lower jaw is derived from second arch (r4) NC. Second, both the lower jaw and tongue skeleton display an organisation which precisely reflects the rostrocaudal order of segmental crest deployment from the embryonic hindbrain. Third, cryptic intraskeletal boundaries, which do not correspond to anatomical landmarks, form sharply defined interfaces between r1+r2, r4 and r6+r7 crest. Cells that survive the early apoptotic elimination of premigratory NC in r3 and r5 are restricted to tiny contributions within the 2nd arch (r4) skeleton. Fourth, a highly constrained pattern of cranial skeletomuscular connectivity was found that precisely respects the positional origin of its constitutive crest: each rhombomeric population remains coherent throughout ontogeny, forming both the connective tissues of specific muscles and their respective attachment sites onto the neuro- and viscerocranium. Finally, focal clusters of crest cells, confined to the attachment sites of branchial muscles, intrude into the otherwise mesodermal cranial base. In the viscerocranium, an equally strict, rhombomere-specific matching of muscle connective tissues and their attachment sites is found for all branchial and tongue (hypoglossal) muscles. This coherence of segmental crest populations explains how cranial skeletomuscular pattern can be implemented and conserved despite evolutionary changes in the shapes of skeletal elements.

Fgf-8 determines rostral-caudal polarity in the first branchial arch

Development ◽  
1999 ◽  
Vol 126 (1) ◽  
pp. 51-61 ◽  
Author(s):  
A.S. Tucker ◽  
G. Yamada ◽  
M. Grigoriou ◽  
V. Pachnis ◽  
P.T. Sharpe
Keyword(s):  
Neural Crest ◽  
Branchial Arch ◽  
Cell Fates ◽  
Spatial Expression ◽  
Mandibular Arch ◽  
Endothelin 1 ◽  
Lower Jaw ◽  
Cell Competence ◽  
Mesenchyme Cells

In mammals, rostral ectomesenchyme cells of the mandibular arch give rise to odontogenic cells, while more caudal cells form the distal skeletal elements of the lower jaw. Signals from the epithelium are required for the development of odontogenic and skeletogenic mesenchyme cells. We show that rostral-caudal polarity is first established in mandibular branchial arch ectomesenchymal cells by a signal, Fgf-8, from the rostral epithelium. All neural crest-derived ectomesenchymal cells are equicompetent to respond to Fgf-8. The restriction into rostral (Lhx-7-expressing) and caudal (Gsc-expressing) domains is achieved by cells responding differently according to their proximity to the source of the signal. Once established, spatial expression domains and cell fates are fixed and maintained by Fgf-8 in conjunction with another epithelial signal, endothelin-1, and by positional changes in ectomesenchymal cell competence to respond to the signal.

scholarly journals Molecular and cellular changes associated with the evolution of novel jaw muscles in parrots

2013 ◽  
Vol 280 (1752) ◽  
pp. 20122319 ◽  
Author(s):  
Masayoshi Tokita ◽  
Tomoki Nakayama ◽  
Richard A. Schneider ◽  
Kiyokazu Agata
Keyword(s):  
Cell Proliferation ◽  
Connective Tissue ◽  
Neural Crest ◽  
Expression Patterns ◽  
Immunohistochemical Analysis ◽  
Connective Tissues ◽  
Cellular Mechanisms ◽  
Jaw Muscles ◽  
Attachment Sites ◽  
Jaw Muscle

Vertebrates have achieved great evolutionary success due in large part to the anatomical diversification of their jaw complex, which allows them to inhabit almost every ecological niche. While many studies have focused on mechanisms that pattern the jaw skeleton, much remains to be understood about the origins of novelty and diversity in the closely associated musculature. To address this issue, we focused on parrots, which have acquired two anatomically unique jaw muscles: the ethmomandibular and the pseudomasseter. In parrot embryos, we observe distinct and highly derived expression patterns for Scx , Bmp4 , Tgf β 2 and Six2 in neural crest-derived mesenchyme destined to form jaw muscle connective tissues. Furthermore, immunohistochemical analysis reveals that cell proliferation is more active in the cells within the jaw muscle than in surrounding connective tissue cells. This biased and differentially regulated mode of cell proliferation in cranial musculoskeletal tissues may allow these unusual jaw muscles to extend towards their new attachment sites. We conclude that the alteration of neural crest-derived connective tissue distribution during development may underlie the spatial changes in jaw musculoskeletal architecture found only in parrots. Thus, parrots provide valuable insights into molecular and cellular mechanisms that may generate evolutionary novelties with functionally adaptive significance.

The cephalic neural crest provides pericytes and smooth muscle cells to all blood vessels of the face and forebrain

Development ◽  
2001 ◽  
Vol 128 (7) ◽  
pp. 1059-1068 ◽  
Author(s):  
H.C. Etchevers ◽  
C. Vincent ◽  
N.M. Le Douarin ◽  
G.F. Couly
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Neural Crest ◽  
Muscle Cells ◽  
Embryonic Cell ◽  
Avian Embryo ◽  
Connective Tissues ◽  
The Face ◽  
Mesodermal Origin ◽  
The Central Nervous System

Most connective tissues in the head develop from neural crest cells (NCCs), an embryonic cell population present only in vertebrates. We show that NCC-derived pericytes and smooth muscle cells are distributed in a sharply circumscribed sector of the vasculature of the avian embryo. As NCCs detach from the neural folds that correspond to the future posterior diencephalon, mesencephalon and rhombencephalon, they migrate between the ectoderm and the neuroepithelium into the anterior/ventral head, encountering mesoderm-derived endothelial precursors. Together, these two cell populations build a vascular tree rooted at the departure of the aorta from the heart and ramified into the capillary plexi that irrigate the forebrain meninges, retinal choroids and all facial structures, before returning to the heart. NCCs ensheath each aortic arch-derived vessel, providing every component except the endothelial cells. Within the meninges, capillaries with pericytes of diencephalic and mesencephalic neural fold origin supply the forebrain, while capillaries with pericytes of mesodermal origin supply the rest of the central nervous system, in a mutually exclusive manner. The two types of head vasculature contact at a few defined points, including the anastomotic vessels of the circle of Willis, immediately ventral to the forebrain/midbrain boundary. Over the course of evolution, the vertebrate subphylum may have exploited the exceptionally broad range of developmental potentialities and the plasticity of NCCs in head remodelling that resulted in the growth of the forebrain.

scholarly journals In Vivo Transplantation of Enteric Neural Crest Cells into Mouse Gut; Engraftment, Functional Integration and Long-Term Safety

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0147989 ◽  
Author(s):  
Julie E. Cooper ◽  
Conor J. McCann ◽  
Dipa Natarajan ◽  
Shanas Choudhury ◽  
Werend Boesmans ◽  
...  
Keyword(s):  
Neural Crest ◽  
Functional Integration ◽  
Neural Crest Cells

scholarly journals Fine-tuning citrate synthase flux potentiates and refines metabolic innovation in the Lenski evolution experiment

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Erik M Quandt ◽  
Jimmy Gollihar ◽  
Zachary D Blount ◽  
Andrew D Ellington ◽  
George Georgiou ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Fine Tuning ◽  
Ecological Niches ◽  
Glta Gene ◽  
Evolutionary Changes ◽  
Before And After ◽  
Evolution Experiment ◽  
History Of ◽  
Second Wave

Evolutionary innovations that enable organisms to colonize new ecological niches are rare compared to gradual evolutionary changes in existing traits. We discovered that key mutations in the gltA gene, which encodes citrate synthase (CS), occurred both before and after Escherichia coli gained the ability to grow aerobically on citrate (Cit+ phenotype) during the Lenski long-term evolution experiment. The first gltA mutation, which increases CS activity by disrupting NADH-inhibition of this enzyme, is beneficial for growth on the acetate and contributed to preserving the rudimentary Cit+ trait from extinction when it first evolved. However, after Cit+ was refined by further mutations, this potentiating gltA mutation became deleterious to fitness. A second wave of beneficial gltA mutations then evolved that reduced CS activity to below the ancestral level. Thus, dynamic reorganization of central metabolism made colonizing this new nutrient niche contingent on both co-opting and overcoming a history of prior adaptation.

Gamma Knife radiosurgery for skull base meningioma: long-term results of low-dose treatment

2008 ◽  
Vol 109 (5) ◽  
pp. 804-810 ◽  
Author(s):  
Yoshiyasu Iwai ◽  
Kazuhiro Yamanaka ◽  
Hidetoshi Ikeda
Keyword(s):  
Malignant Transformation ◽  
Gamma Knife ◽  
Low Dose ◽  
Gamma Knife Radiosurgery ◽  
Cranial Base ◽  
Local Failure ◽  
Long Term Results ◽  
Early Results

Object In this study, the authors evaluate the long-term results after Gamma Knife radiosurgery of cranial base meningiomas. This study is a follow-up to their previously published report on the early results. Methods Between January 1994 and December 2001, the authors treated benign cranial base meningiomas in 108 patients using low-dose Gamma Knife radiosurgery. The tumor volumes ranged from 1.7 to 55.3 cm3 (median 8.1 cm3), and the radiosurgery doses ranged from 8 to 12 Gy (median 12 Gy) to the tumor margin. Results The mean duration of follow-up was 86.1 months (range 20–144 months). Tumor volume decreased in 50 patients (46%), remained stable in 51 patients (47%), and increased (local failure) in 7 patients (6%). Eleven patients experienced tumor recurrence outside the treatment field. Among these patients, marginal failure was seen in 5 and distant recurrence was seen in 6. Seven patients were thought to have malignant transformation based on histological or radiological characteristics of the lesion. The actuarial progression-free survival rate, including malignant transformation and outside recurrence, was 93% at 5 years and 83% at 10 years. Neurological status improved in 16 patients (15%). Permanent radiation injury occurred in 7 patients (6%). Conclusions Gamma Knife radiosurgery is a safe and effective treatment for cranial base meningiomas as demonstrated with a long-term follow-up period of > 7 years. Surgeons must be aware of the possibility of treatment failure, defined as local failure, marginal failure, and malignant transformation; however, this may be the natural course of meningiomas and not related to radiosurgery.

Tissue interactions and the initiation of osteogenesis and chondrogenesis in the neural crest-derived mandibular skeleton of the embryonic mouse as seen in isolated murine tissues and in recombinations of murine and avian tissues

Development ◽  
1980 ◽  
Vol 58 (1) ◽  
pp. 251-264
Author(s):  
Brian K. Hall
Keyword(s):  
Neural Crest ◽  
Embryonic Mouse ◽  
Mandibular Arch ◽  
Tissue Interactions ◽  
Ability To Act ◽  
Sufficient Stimulus ◽  
And Cartilage

Mandibular processes from 9- to 13-day-old embryonic mice formed both bone and cartilage when grafted to the chorioallantoic membranes of host embryonic chicks. Isolated ectomesenchyme, taken from 9-day-old embryos did not form bone or cartilage, while older ectomesenchyme formed both. Recombination of the epithelial and ectomesenchymal components confirmed that the presence of the epithelium was a sufficient stimulus for the initiation of both chondro- and osteogenesis. Recombinations between components of mouse and chick mandibular processes showed that 9-day-old mouse ectomesenchyme could respond to chick epithelium but that, although older murine epithelia could initiate osteogenesis from the avian ectomesenchyme, epithelia from 9-day-old embryos could not. These results indicated that an epithelial-ectomesenchymal interaction was responsible for the initiation of both osteo- and chondrogenesis within the mandibular arch of the mouse; that the interaction began at 10 days of gestation; that the ectomesenchyme was capable of responding at 9 days, but that the epithelium did not acquire its ability to act on the ectomesenchyme until 10 days of gestation.

The Occurrence and Morphogenesis of Melanocytes in the Connective Tissues of the PET/MCV Mouse Strain1

Development ◽  
1960 ◽  
Vol 8 (1) ◽  
pp. 24-32
Author(s):  
Stuart E. Nichols ◽  
Willie M. Reams
Keyword(s):  
Neural Crest ◽  
The Body ◽  
Connective Tissues ◽  
Medical College ◽  
Genital Apparatus ◽  
Mouse Tissues ◽  
Harderian Glands ◽  
Neural Crest Origin ◽  
The Brain ◽  
Made In

Mammals, as a rule, are described as having melanocytes of neural crest origin confined almost entirely to the skin. Of the organs other than skin which have been described as possessing melanocytes are portions of the gonado-genital apparatus of the Opossum (Burns, 1939), and, in the house mouse, tissues of the nictitans, the meninges of the brain, the parathyroids, the thymus and harderian glands (Markert & Silvers, 1956), and the parathyroids of C58 mice (Dunn, 1949). The present investigation has been made in a strain of mice in which melanocytes are found in the connective tissues throughout much of the body. This strain originated several years ago in the Department of Genetics, Medical College of Virginia, from a cross between inbred C3H and black mice of unknown breed obtained from a local pet shop. Because of the latter circumstance, the line-bred progeny have been termed the PET/MCV strain.

sucker encodes a zebrafish Endothelin-1 required for ventral pharyngeal arch development

Development ◽  
2000 ◽  
Vol 127 (17) ◽  
pp. 3815-3828 ◽  
Author(s):  
C.T. Miller ◽  
T.F. Schilling ◽  
K. Lee ◽  
J. Parker ◽  
C.B. Kimmel
Keyword(s):  
Neural Crest ◽  
Expression Patterns ◽  
Neural Crest Cells ◽  
Paraxial Mesoderm ◽  
Dorsoventral Patterning ◽  
Surface Ectoderm ◽  
Pharyngeal Arches ◽  
Endothelin 1 ◽  
Lower Jaw ◽  
Arch Neural

Mutation of sucker (suc) disrupts development of the lower jaw and other ventral cartilages in pharyngeal segments of the zebrafish head. Our sequencing, cosegregation and rescue results indicate that suc encodes an Endothelin-1 (Et-1). Like mouse and chick Et-1, suc/et-1 is expressed in a central core of arch paraxial mesoderm and in arch epithelia, both surface ectoderm and pharyngeal endoderm, but not in skeletogenic neural crest. Long before chondrogenesis, suc/et-1 mutant embryos have severe defects in ventral arch neural crest expression of dHAND, dlx2, msxE, gsc, dlx3 and EphA3 in the anterior arches. Dorsal expression patterns are unaffected. Later in development, suc/et-1 mutant embryos display defects in mesodermal and endodermal tissues of the pharynx. Ventral premyogenic condensations fail to express myoD, which correlates with a ventral muscle defect. Further, expression of shh in endoderm of the first pharyngeal pouch fails to extend as far laterally as in wild types. We use mosaic analyses to show that suc/et-1 functions nonautonomously in neural crest cells, and is thus required in the environment of postmigratory neural crest cells to specify ventral arch fates. Our mosaic analyses further show that suc/et-1 nonautonomously functions in mesendoderm for ventral arch muscle formation. Collectively our results support a model for dorsoventral patterning of the gnathostome pharyngeal arches in which Et-1 in the environment of the postmigratory cranial neural crest specifies the lower jaw and other ventral arch fates.

scholarly journals A Five-Year Data Report of Long-Term Central Venous Catheters Focusing on Early Complications

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Harald Lenz ◽  
Kirsti Myre ◽  
Tomas Draegni ◽  
Elizabeth Dorph
Keyword(s):  
Demographic Data ◽  
Venous Catheter ◽  
Venous Access ◽  
Seldinger Technique ◽  
Published Data ◽  
Main Diagnosis ◽  
Anatomical Landmarks ◽  
Central Venous ◽  
Jugular Veins

Background. Long-term venous access has become the standard practice for the administration of chemotherapy, fluid therapy, antibiotics, and parenteral nutrition. The most commonly used methods are percutaneous puncture of the subclavian and internal jugular veins using the Seldinger technique or surgical cutdown of the cephalic vein. Methods. This study is based on a quality registry including all long-term central venous catheter insertion procedures performed in patients >18 years at our department during a five-year period. The following data were registered: demographic data, main diagnosis and indications for the procedure, preoperative blood samples, type of catheter, the venous access used, and the procedure time. In addition, procedural and early postoperative complications were registered: unsuccessful procedures, malpositioned catheters, pneumothorax, hematoma complications, infections, nerve injuries, and wound ruptures. The Seldinger technique using anatomical landmarks at the left subclavian vein was the preferred access. Fluoroscopy was not used. Results. One thousand one hundred and one procedures were performed. In eight (0.7%) cases, the insertion of a catheter was not possible, 23 (2.1%) catheters were incorrectly positioned, twelve (1.1%) patients developed pneumothorax, nine (0.8%) developed hematoma, and three (0.27%) developed infection postoperatively. One (0.1%) patient suffered nerve injury, which totally recovered. No wound ruptures were observed. Conclusions. We have a high success rate of first-attempt insertions compared with other published data, as well as an acceptable and low rate of pneumothorax, hematoma, and infections. However, the number of malpositioned catheters was relatively high. This could probably have been avoided with routine use of fluoroscopy during the procedure.

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