Musculoskeletal System - Limb Development: Difference between revisions
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* '''Spatially Controlled Cell Proliferation in Limb Bud Morphogenesis'''<ref name="PMID20644711"><pubmed>20644711</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903592/ PMC2903592] | [http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000420 PLoS]</ref>"Our data run contrary to the proliferation gradient hypothesis, indicating instead that oriented cell behaviours are important for driving elongation." | * '''Spatially Controlled Cell Proliferation in Limb Bud Morphogenesis'''<ref name="PMID20644711"><pubmed>20644711</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903592/ PMC2903592] | [http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000420 PLoS]</ref>"Our data run contrary to the proliferation gradient hypothesis, indicating instead that oriented cell behaviours are important for driving elongation." | ||
* '''The apical ectodermal ridge (AER) can be re-induced by wounding'''.<ref name="PMID20347761"><pubmed>20347761</pubmed> "First, we assessed the sequence of events following limb amputation in chick embryos and compared the features of limb development and regeneration in amphibians and chicks. Based on our findings, we attempted to re-induce the AER. When wnt-2b/fgf-10-expressing cells were inserted concurrently with wounding, successful re-induction of the AER occurred." | * '''The apical ectodermal ridge (AER) can be re-induced by wounding'''.<ref name="PMID20347761"><pubmed>20347761</pubmed><ref> "First, we assessed the sequence of events following limb amputation in chick embryos and compared the features of limb development and regeneration in amphibians and chicks. Based on our findings, we attempted to re-induce the AER. When wnt-2b/fgf-10-expressing cells were inserted concurrently with wounding, successful re-induction of the AER occurred." | ||
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Revision as of 13:37, 22 September 2010
Introduction
The mesoderm forms nearly all the connective tissues of the musculoskeletal system. Each tissue (cartilage, bone, and muscle) goes through many different mechanisms of differentiation.
The musculoskeletal system consists of skeletal muscle, bone, and cartilage and is mainly mesoderm in origin with some neural crest contribution.
The intraembryonic mesoderm can be broken into paraxial, intermediate and lateral mesoderm relative to its midline position. During the 3rd week the paraxial mesoderm forms into "balls" of mesoderm paired either side of the neural groove, called somites.
Somites appear bilaterally as pairs at the same time and form earliest at the cranial (rostral,brain) end of the neural groove and add sequentially at the caudal end. This addition occurs so regularly that embryos are staged according to the number of somites that are present. Different regions of the somite differentiate into dermomyotome (dermal and muscle component) and sclerotome (forms vertebral column). An example of a specialized musculoskeletal structure can be seen in the development of the limbs.
Skeletal muscle forms by fusion of mononucleated myoblasts to form mutinucleated myotubes. Bone is formed through a lengthy process involving ossification of a cartilage formed from mesenchyme. Two main forms of ossification occur in different bones, intramembranous (eg skull) and endochondrial (eg limb long bones) ossification. Ossification continues postnatally, through puberty until mid 20s. Early ossification occurs at the ends of long bones.
Musculoskeletal and limb abnormalities are one of the largest groups of congenital abnormalities.
System Links: Introduction | Cardiovascular | Coelomic Cavity | Endocrine | Gastrointestinal Tract | Genital | Head | Immune | Integumentary | Musculoskeletal | Neural | Neural Crest | Placenta | Renal | Respiratory | Sensory | Birth |
--Mark Hill 09:25, 14 April 2010 (EST) Page Template only - content from original UNSW Embryology site currently being edited and updated.
Some Recent Findings
Four Concepts - much of the work has been carried out using the chicken and more recently the mouse model of development.
Limb Initiation
Note that during the embryonic period there is a rostrocaudal (anterior posterior) timing difference between the upper and lower limb development
Limb IdentityForelimb and hindlimb (mouse) identity appears to be regulated by T-box (Tbx) genes, which are a family of transcription factors.
Related Research - PMID: 12490567 | Development 2003 Figures | Scanning electron micrographs of E9 Limb bud wild-type and Tbx5del/del A model for early stages of limb bud growth | PMID: 12736217 | Development 2003 Figures Body Axes
Proximodistal Axis
apical ectodermal ridge | AER and vascular channel Dorsoventral Axis
Wnt7a
One WNT receptor is Frizzled (FZD)
Fibroblast growth factors (FGF)
FGF receptors
Anteroposterior Axis
Wing as Limb Model
UNSW Embryology - Axes Formation - Limb | Signal Factors - Wnt
References
Reviews
Articles
Search PubMedSearch April 2010
Additional ImagesTermsGlossary Links
Cite this page: Hill, M.A. (2024, May 17) Embryology Musculoskeletal System - Limb Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Musculoskeletal_System_-_Limb_Development
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