Figure 6. Ret and Gfrα1 Patterns Facilitate Pea3 Induction in MN Pools.
(A–D) Misexpression of Ret under pCAGGs induces Pea3 expression in thoracic MNs but not rostral brachial LMC neuron. (E–H) Gfrα1 missexpression fails to induce Pea3 expression in rostral brachial and thoracic MNs. (I–N) Co-expression of Ret and Gfrα1 is sufficient to induce Pea3 at both rostral brachial and thoracic levels. (O–P) After induction of Pea3 by Ret and Gfrα1 there is a reduction in the number of Scip+ LMC neurons. (Q) Quantification showing increased numbers of Pea3+ and reduced Scip+ MNs along the rostrocaudal axis after Ret and Gfrα1 misexpression. Numbers are representative of electroporation experiments with efficiencies of greater than 50%. (R) Diagram summarizing the relationship between Ret, Gfrα1, Scip and Pea3 expression, as well as the effects of Ret and Gfrα1 misexpression on the differentiation of Pea3+ and Scip+ MN pools. See also Figure S6.