The majority of sampling was carried out with 10X Genomics Chromium Single Cell Kit Version 1, although part of the hindbrain sampling was done in Version 2 (Table S1). Suspensions were prepared as described above and diluted in aCSF, to concentrations between 300-1000 cells/μl (listed in Table S1), and added to 10x Chromium RT mix to achieve loading target numbers between 2500-8000 (V1 kit) or 7000-10,000 (V2 kit), as indicated. For downstream cDNA synthesis (12-14 PCR cycles), library preparation, and sequencing, we followed the manufacturer’s instructions.
