For Bulk RNA-seq, P2 mouse cerebella were dissected from individual pups in cold PBS and immediately processed for total RNA extraction. For scRNA-seq, P7 cerebella were dissected from individual pups (one cerebellum per sample, no pooling) and dissociated into a single-cell suspension with a papain-based kit (Miltenyi Biotec 130-094-802); 1 × 10⁶ cells per animal were fixed with the Parse Biosciences Evercode Fixation v3 kit (ECWT3300), slow-frozen in a Mr. Frosty container, and stored at −80 °C until library preparation. For ATAC-seq, P2 cerebella were dissected in cold PBS and nuclei isolated by brief lysis in cold ATAC lysis buffer prior to Tn5 tagmentation. For CUT&RUN, P2 cerebella were dissected in cold PBS, dissociated into a single-cell/nuclei suspension, immobilized on Concanavalin A–coated magnetic beads, and processed for antibody incubation and pAG-MNase digestion. For Bulk RNA-seq, total RNA was isolated from P2 cerebella using the Direct-zol RNA MiniPrep kit (Zymo Research #R2052), and sequencing libraries were prepared with the Illumina Stranded Total RNA Prep library kit (Illumina #20040529) according to the manufacturer's instructions. For scRNA-seq, fixed cells were thawed and loaded onto the Parse Biosciences Evercode WT v3 kit, then processed through split-pool combinatorial barcoding per the manufacturer's protocol with a target recovery of ~100,000 cells. For ATAC-seq, nuclei isolated from P2 cerebella were tagmented with the Tn5 transposase using the ATAC-seq kit (Active Motif 53150) and libraries were prepared according to the manufacturer's instructions. For CUT&RUN, cells/nuclei from P2 cerebella were bound to Concanavalin A–coated magnetic beads and incubated at room temperature for 4 h with antibodies against TEAD1, HA (for INSM1 in Insm1^HA/HA^ tissue), KDM1A, H3K4me3, H3K27me3, or H3K27ac, or rabbit IgG as a negative control; chromatin was digested by Ca²⁺-activated pAG-MNase, released fragments purified, and libraries prepared. CUT&RUN libraries were prepared using the NEBNext Ultra II kit (NEB #E7103) with modifications as in https://dx.doi.org/10.17504/protocols.io.bagaibse. Library size and quality for all assays were assessed on an Agilent TapeStation/ Bioanalyzer prior to sequencing.