DEV002879 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure S1 -

  Fig. S1. Lmx1a is selectively expressed in mesDA neurons. Virtually all neurons generated from Lmx1a⁺ domains are mesDA neurons at E12.5. Nurr1 and Lmx1b are expressed in almost all of the Lmx1a⁺ postmitotic precursors in the ML. Pitx3 and En1/2 are expressed in more mature mesDA neurons.

• Supplemental Figure S2 -

  Fig. S2. Expression patterns for Lmx1a, Lmx1b, Ngn2 and Mash1 in the ventral mesencephalon between E9.5 and E11.5.

• Supplemental Figure S3 -

  Fig. S3. The reduction in the numbers of Th⁺ and Lmx1b⁺ mesDA neurons is not rescued at later developmental stages. Images show the VTA region at E16.5.

• Supplemental Figure S4 -

  Fig. S4. mesDA neurons are reduced in number but marker expression is mostly normal in dreher mutants at E12.5.

• Supplemental Figure S5 -

  Fig. S5. Innervation of Th⁺ fibers into the striatum is normal in dreher mutants at P10.

• Supplemental Figure S6 -

  Fig. S6. mesDA precursors with ectopic Lim1/2 in dreher mutants cannot differentiate into mature mesDA neurons. Most of the Lim1/2⁺ Lmx1b⁺ neurons in dreher mutants do not express Pitx3 (B, white arrowhead) although some Lim1/2⁺ Lmx1b⁺ Pitx3⁺ neurons were observed (yellow arrowhead).

• Supplemental Figure S7 -

  Fig. S7. FP4 specifically marks FP cells in the mesencephalon. In the rat E13.5 spinal cord and metencephalon, Shh, Hnf3β and FP4 were specifically expressed in FP cells. In the mesencephalon, however, Shh and Hnf3β were broadly expressed in the ventral region including Nkx6.1⁺ neural progenitor domain. By contrast, FP4 specifically marks FP cells in all A-P locations.

• Supplemental Figure S8 -

  Fig. S8. Lmx1a is not sufficient for the induction of neurogenesis in caudal FP cells. Lmx1a is ectopically expressed under the control of the FP-specific enhancer of the Shh gene. Images show the ventral midline region of the anterior metencephalon. The transgene is selectively expressed in the cFP region. In transgenic embryos, Ngn2 is not induced in caudal FP cells as it is in wild-type controls at E12.5, and consequently, HuC/D⁺ neurons are not generated ectopically.