chapter 14 the neural crest
TRANSCRIPT
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 1/32
Joson, Angelo Eleno F.
4BIO 6
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 2/32
Neural Crest
Labeled as thefourth germ lay er
Gives rise tonumerous structuresin both cranial and
caudal parts of anembr y o
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 3/32
Evolution of Neural
Crest
Homologous to protochordatedorsal midline epidermis
Emergence of new cell properties:
1. Pluripotenc y
2. Delamination-migration
3. Anteroposterior positional
v alue4. Complex craniof acial structure
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 4/32
Controlling Genes
Protochordates:
BMP Factors
- Transforming Growth Factor
(TGF-)-BMP4 and BMP7
Vertebrates
- Neuropilin 1
- Sox10
- Sema3a
N-cadherin
rhoB
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 5/32
Markers for Tracing
Slug/Snail
-Zinc finger genes
-Induction and subsequent
migration
-R adioactive isotopes
--staining antibodies
- (NC-1, HNK-1)
-- lipophilic d y es (DiI)
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 6/32
Origins of the
Neural Crest Cells Arise from neural tube
From dorsal midline
Emergence occur from anterior to
posterior parts of embr y o
Pinch off from neural epithelium just as the neural tube forms
Emerge as mesench y mal cells
(Mour y and Jacobson) Experimenton axolotls: NCCs form at borderbetween neural plate andepidermis
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 7/32
Origins of the
Neural Crest(Scherson and associates)Experiment on chick embr y os:NCCs can form in other parts of neural tube aside from the dorsalside
Upon formation, the y lose celladhesion molecules
- N-CAM
- N-cadherin
Levels of fibronectin and othersurf ace matrix molecules rise
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 8/32
Migration of Neural Crest Cells
NCCs loseN-cadherinand becomestimulatedto migrate
NCCs lea ve the
neural tubearea
NCCs enter a cell-free zonedispersed withextracellularmatrix
Gene f actorsf acilitatemigration
Interact withtissues andbecomelocalized to formspecializedstructures
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 9/32
Migration of Neural Crest Cells
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 10/32
Migration of Neural Crest Cellsy Influences of extracellular matrix
y Laminin
y Fibronectiny T y pe IV collagen
y Chondroitin sulf ate
y H yaluronic Acid
y Heparan Sulf atey Integrins
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 11/32
Migration of Neural Crest Cells
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 12/32
Loo Aka Chu, Charisa Camille C.
4 Bio - 6
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 13/32
Differences in premigratory neural crest cells:
1. Not all shows the same staining properties whenexposed to monoclonal antibodies or
histochemical reagents
2. Single neural crest cells do not all produce the
same types of differentiated progeny
3. When pieces of neural tube are grafted intodifferent craniocaudal levels, some neural crest
derivatives do not form.
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 14/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 15/32
1. Embryonic tissues
2. Envir onment
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 16/32
Cranial Crest Trunk Crest
Nervous System:Sensory Nervous
System
Ganglia:
(V) Trigeminal nerve
(VII) Facial nerve (root)
(IX) Glossopharyngeal (Superior
ganglion)
(X) Vagus nerve (Jugular ganglion)
Spinal ganglia
Rohon-beard cells (amphibian
larvae)
Autonomic Nervous
System
Parasympathet ic ganglia:
Ciliary
Ethmoidal
Sphenopalat ine
SubmandibularVisceral
Parasympathet ic ganglia:
Pelvic plexus
Remaks (birds)
Visceral
Sympathet ic ganglia:
Superior cervical
Paravert ebral
Prevert ebral
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 17/32
Cranial Crest Trunk Crest
Noneural cells Oligodendroglia
Sat elit e cells of sensory ganglia
Schwann cells of peripheralnerves
Neuromasts
Sat elit e cells of ganglia
Schwann cells of peripheral
nervesNeuromasts (f ish lat eral lines)
Pigment cells Melanopores
Xanthopores
Erythrophores
Iridophores
Melanopores
Xanthopores
Erythrophores
Iridophores
Endocrine and
Paraendocrine
cells
Calcitonin-producing cells
Carot id body
Parafollicular cells (Thyroid)
Adrenal medulla
Neurosecretory cells of heart
and lungs
Mesectodermal
cells
Skeleton
Cranial vault
Nasal and orbit al
Ot ic capsule
Palat e and maxillary
Sphenoid
Trabeculae
Visceral cart ilages
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 18/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 19/32
Neural crest Derivative Interacting Structure
Bones of Cranial Vault Brain
Bones of base of skull Notochord, brain
Pharyngeal ar ch car tilages Pharyngeal endoderm
Meckel·s Car tilage Cranial ectoderm
Maxillary bone Maxillary ectoderm
Mandible Mandibular ectoderm
Palate Palatal ectoderm
Otic capsule Otic vesicle
Dentine of teeth Oral ectoderm
Glandular str oma: thyr oid,
parathyr oid, thymus, salivary
Local epithelium
Adr enal medullary chr omatin cells Glucocor ticoids secr eted by adr enal cor te x
Enter ic neur ons Gut wall
Sympathetic neur ons Spinal cord, notochord, somites
Sensory neur ons Per ipheral tar get tissue
Pigment cells Extracellular matr i x along pathway of
migration
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 20/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 21/32
Trunk Neural Crest Cells extends from the caudal part of the embryo until
the 6th somite
cells disperse after neural tube closes multipotent cells
3 major pathways: dorsolateral , ventral &ventromedial
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 22/32
Neural Crest Migration
In Mammals, melanocytes
distribute pigment granules to
basal ectodermal cells
In lower vertebrates, pigment
cells remain underneath the
ectoderm
Dorsolateral
Between dorsal
ectoderm &
somites
Pigment Cells or
Melanocytes
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 23/32
Somite and dorsal
aorta
Ventral route
Between somites
and neural tube
Ventromedial
Paired spinal
ganglia
Sympathoadrenal
lineage
Sympathetic Nervous
System &
Adrenal Medulla
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 24/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 25/32
Sympathoadrenal lineage
Gives rise to bipotential progenitor cells -->
sympathetic neurons ( FGF / F ibroblast
Growth
F actor ) and chromaffin cells
Future adrenal gland
Chromaffin cells : gland-like cells active in
forming neurotransmitters; reacts withchromic acid salts
adrenal medulla
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 26/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 27/32
Gershon & associates (1993) - moreneurons are present in the gut than in the
spinal cord.
Shift-level transplantation experiments
Gut releases a short-range diffusible factor
proliferate neural crest or neuroepithelial
cells
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 28/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 29/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 30/32
Hoxb gene complex Hoxb-2, 3 and 4 gene products first
expressed in neural tube
Expression of same Hox genes;
interaction between ectoderm and neural
crest cells in branchial arches
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 31/32
8/8/2019 Chapter 14 the Neural Crest
http://slidepdf.com/reader/full/chapter-14-the-neural-crest 32/32
Cranial neural crest cells are
imprinted with morphogenetic
instruction that could relate to
their level of origin.
Wider assortment of cell
types