Dale Frank Lab
Department of Biochemisty
Rappaport Faculty of Medicine
Technion - Israel Institute of Technology
RESEARCH
The journey from EGG to FROG!
Meis3: A TALE-Family Homeobox Protein Controls Posterior Neural Cell Fates in Vertebrates
A. Over-expression of Meis3 protein INHIBITS FOREBRAIN, while ENHANCING HINDBRAIN cell fates.
B. Meis3 protein knock down INHIBITS HINDBRAIN, PRIMARY NEURON & NEURAL CREST fates, while EXPANDING the FOREBRAIN.
C. Meis3 Protein acts downstream to mesodermal Wnt3a protein to caudalize the nervous system.
A
Control
Ectopic Meis3 Expression
B
Control
Meis3 Protein
Knock Down
C
Meis3 protein restores posterior neural cell fates in the absence of canonical Wnt signaling.
Left Panel: Morphology of mid-late neurula embryos (a) injected at the one-cell stage with either Wnt3a Morpholino (MO) (b), or Meis3 mRNA (c), or doubly-injected with both (d). Neural plate folding and convergence extension-elongation is strongly-inhibited in Wnt3a morphant embryos (b); Meis3 co-expression rescued this phenotype (d). All embryos are viewed dorsally, and oriented with anterior at the top, posterior at the bottom.
Right Panel: In situ hybridization of mid-late neurula embryos (a,e,i,m,q) injected at the one-cell stage with either Wnt3a-MO (b,f,j,n,r), or separately with Meis3 mRNA (d,h,l,p,t) or doubly-injected with both (c,g,k,o,s). Anterior-forebrain-specific XAnf1 expression is posteriorly expanded in Wnt3a-morphants (b), and suppressed by Meis3 co-expression (c,d). Expression of the posterior neural markers Krox20 (hindbrain), HoxB3 (hindbrain), N-Tub (primary neuron) and FoxD3 (neural crest) is inhibited in Wnt3a-morphants (f,j,n,r), but rescued by Meis3 co-expression (g,k,o,s). All embryos are viewed dorsally, and oriented with anterior at the top, posterior at the bottom.