PROJECT 1:
Origin and regulation of motor neuron identity in the hindbrain
Gary O. Gaufo, UTSA
Anne M. Moon, University of Utah
Ruru Chen, UTSA Neurobiology Program
NINDS Specialized Neuroscience Research Program
Student Career & Collaboration
Visceral sensory precursors
Postganglionic precursors
• postdoctoral fellow with A. Chan at Emory University
• developing nonhuman primate and mouse models of Huntington’s disease
with an emphasis on stem cell biology
• Charles Wang advised Ruru on statistics, and continues imbedding duties
SUMMARY
Current Progress & Milestones
• SNRP Output: 6-7 papers; 1 funded R01; 2 ad hox NIH review sections
• Specific Aim 1. Characterize the migration, differentiation, and Hox
requirement of neural crest-derived postganglionic motor neurons.
3 Published manuscripts
Waardenburg Syndrome rescue (complete in Year 5)
• Specific aim 2: Determine the role of Hoxb1 in postmitotic facial
branchial motor neurons.
Manuscript draft written
• Specific aim 3. Determine role of Fgf8 and Fgfr1/2 on parasympathetic
motor & sensory ganglia development (Gaufo & Moon).
1 Published manuscript
Acquiring data for 2nd manuscript (complete in Year 5)
Specific aim 2: Determine the role of Hoxb1 in
postmitotic facial branchial motor neurons.
Germline loss of Hoxb1 results in transformation of
r4 branchial motor neurons into r2-like branchial motor neurons
Hoxb1-/-
TBMN
r4
r3
r2
Control
TBMN
FBMN
BMN
CBMN
r6
r5
CBMN
FBMN
Isl1 Phox2b Gata3
BMN
Isl1 Phox2b Gata3
Gaufo & Chen, Unpublished Data
Determine Hoxb1 function in postmitotic motor neurons
Hoxb1
Hoxb1 Isl1
Dorsal
BMN
Progenitor
Domain
Ventricular
zone
Marginal
zone
Ventral
Postmitotic
BMNs
Facial branchial
MN domain
Rhombomere 4 (r4)
Hoxb1GFP
Ex1
Isl1
Ex1
Cre excises exons 1 & 2
in the Isl1 domain
Loss of Hoxb1
function & GFP reporter
in facial branchial
motor neurons
Cre
Gaufo & Chen, Unpublished Data
Hoxb1 activity in postmitotic motor neurons is required for migration
Control (Hoxb1G/+)
r3
r2
TBM
Hoxb1G/C; Isl1Cre/+
anterior
r4
r5
r5
r4
r4
r5
r6
FVM
r6
posterior
FBM
Hoxb1GFP
Hoxb1GFP
Gaufo & Chen, Unpublished Data
Summary: Hoxb1 restricts multi-potent postmitotic motor neuron pool
toward a specific branchial motor neuron lineage
r2
r3
ba2
r4
r5
r5
FBMN
r6
FVMN
r6
ba2
CBMN
r4
r3
r2
ba1
TBMN
ba1
Hoxb1 loss in postMNs
Control
Gaufo & Chen, Unpublished Data
Applying the basic principle of Hox gene function to disease
Why do certain genetic diseases originate in
specific tissue coordinates of the body?
Human genetic disorders:
Waardenburg Syndrome (WS) & Hirschprung’s Disease
Pax3+/- or Sox10+/- associated neural crest defects
Specific Aim 1. Characterize the migration, differentiation,
& Hox requirement of neural crest-derived
postganglionic motor neurons.
Boundary cap cells maintain integrity of the nervous system
Neural Crest-Derived Boundary Cap Cells
CNS-r4
CNS-r4
PNS-VIIIg
PNS-VIIIg
Pax3 Krox20
Sox10 Krox20
Gaufo et al., Unpublished Data
Sox10 is required for the formation of boundary cap cells
Sox10-/-
Control
CNS-r4
CNS-r4
PNS-VIIIg
PNS-VIIIg
Sox10 Krox20
Gaufo et al., Unpublished Data
Abnormal migration in absence of boundary cap cells
Sox10-/-
Control
CNS-r4
CNS-r4
PNS-VIIIg
PNS-VIIIg
Tuj1 Isl1
Gaufo et al., Unpublished Data
Sensitivity of boundary cap cells to Pax3/Sox10 along the AP axis
Pax3+/-; Sox10+/-
Control
CNS-r4
CNS-r4
PNS-VIIIg
PNS-VIIIg
Tuj1 Isl1
Gaufo et al., Unpublished Data
ba2
r2
r4
r2 NC-derived BC cell
r4 NC-derived BC cell
Sensory ganglion
ba2
r2
r3
r2
r3
Change AP identity of
Pax3+/-Sox10+/- deficient NC
r4
ba1
r3
ba1
ba2
Pax3+/-Sox10+/deficient neural crest
r4
ba1
Model for rescuing boundary cap cell defect in WS mouse model
Gaufo et al., Unpublished Data
Strategy to transform identity of r4 neural crest-derived
Pax3/Sox10-deficient boundary cap cells
Cell autonomous
loss of Hoxb1, Sox10, & Pax3
Hoxb1
Sox10
Pax3 Cre
2x
1x
Prediction:
change in r4 NC
identity rescues
BC-associated defect
1x
Gaufo et al., Unpublished Data
Hox-dependent rescue of boundary cap cell defect in WS mouse model
Control
CNS-r4
PNS-VIIIg
Pax3Cre/+;
Sox10F/+
Pax3Cre/+; Sox10F/+;
Hoxb1F/F
CNS-r4
CNS-r4
PNS-VIIIg
PNS-VIIIg
Isl1 Tuj1
Gaufo et al., Unpublished Data
ba2
r2
r4
r2 NC-derived BC cell
r4 NC-derived BC cell
Sensory ganglion
ba2
r2
r3
r2
r3
Change AP identity of
Pax3+/-Sox10+/- deficient NC
r4
ba1
r3
ba1
ba2
Pax3+/-Sox10+/deficient neural crest
r4
ba1
Prototype model for rescuing diseases w/ specific AP positional signatures
Gaufo et al., Unpublished Data
Food for thought: Can the fate of pediatric medulloblastoma be altered?
Pediatric Medulloblastoma
Anterior
Dorsal
Ventral
Posterior
Hedgehog Signaling Defect
Modified from www.medscape.com
ACKNOWLEDGEMENTS
Former Members
• Ruru Chen, PhD
• Masumi Takano-Maruyama, PhD
• Karen Kao
Current Members
• Meizhen Chen, PhD
• Oscar Trevino
• Angela Huang
Neurosciences Institute @ UTSA (Charlie, Salma, & Greg)
SNRPhriday Group
Image Analysis (Colleen) & Statistical Cores (DJ)
funded by…
NIH-NINDS, NIH-NIA, Whitehall Foundation, & SALSI