Cross-Pipeline RNA-seq Analysis Reveals Core Regulatory Gene Signatures Driving P19 Cell Neurogenesis

I. Understanding the mechanisms governing neuronal differentiation is essential for elucidating neurodevelopmental processes and identifying therapeutic targets for neurological disorders. In this study, we optimized serum-dependent induction conditions and benchmarked multiple RNA-seq pipelines to establish a robust in-vitro model of neurogenesis using P19 embryonal carcinoma cells. Retinoic acid (RA, 0.5 µM) was used to induce neuronal differentiation under varying concentrations (1%, 2%, and 5%) of fetal bovine serum (FBS) obtained from three suppliers. Morphological observation and marker gene analysis (MAP2, OCT4) revealed that serum concentration strongly influenced aggregation, survival, and neuronal commitment, with 2–5% FBS yielding optimal neurogenic differentiation. Total RNA extracted on day 10 of differentiation was subjected to RNA sequencing, and the resulting datasets were analyzed using four independent bioinformatics workflows: a Linux-based R pipeline (HISAT2 + featureCounts + DESeq2), nf-core, Galaxy, and BGI’s Dr. Tom platform. Differential gene expression analysis identified 9,943 differentially expressed genes (DEGs) (FDR 1), enriched in synaptic assembly and axon development among upregulated genes, and in ribosome biogenesis and RNA processing among downregulated genes. Comparison across all pipelines revealed 62 consistently upregulated and 63 downregulated genes, representing a robust core signature of P19 neurogenesis. Together, these findings establish an optimized and reproducible framework for in-vitro neuronal differentiation and transcriptomic analysis, providing a foundation for mechanistic and disease-modeling studies in neurodevelopmental biology.